[CTVTinoco]

No complaints so far, but not sure it'd be worth swapping from one to the other.
I had them fab it with a smaller fill cap (wasnt ever planning on using ice) cap isn't tiny if i really wanted to ice it wouldn't be too hard. And at the time I was gung-ho with insane cooling-cwa400/16an lines. So I had them weld an bungs on instead of the hose barbs. Ended up using the dms cwa150 and 12an hoses. LMP still had it from order to shipped within like a week, including powdercoat.
Would start with pump/hoses if you haven't already before swapping the tanks

Thanks for the update! I did get a CWA 150 so I'll do that first and go from there. Solid build you have.

 

[randeez]

New year update...
Had another issue with the in-tank pumps, symptom- wouldnt maintain fuel pressure again, even worse this time. diagnosed everything i could without dropping tank again but no luck. At this point kind of conceded defeat and external aux pump wouldve been much less drama, if i could leave it alone when aux pump max'd out anyway. so tank had to come back down.
problem this time, was the hose that makes a 180° to the primary pump. the hose was too long (my fault i guess) when you stuff this monstrosity back into the tank the hose was actually sitting against the top of the tank (its offset from the fuel hat). hose didnt rub through or anything, i think it was just smushed in there and ended up splitting the hose. I had a hell of a time getting these corrugated hoses on the first time so i ended up replacing both of the hoses while it was out(shorter hose between these two), re-crimping them. has been fine since.

one other seemingly random issue is my car makes a lazy 4>5 shift. part of it is the larger gap in gearing after 1-4 shifts, but also in the logs shows shift times .7+. so one morning i was just cruising not even really beating on it and went to pass on the highway and it sort of acted like it popped out gear the way an old shitty manual would and rev'd to redline, CEL, then just wouldnt make any 5,6,7 shifts. i didnt have anything to check/clear codes with me, middle of rush hour morning traffic. it would make first couple shifts and get up to like 50-60mph and then you could feather it into 8th and lockup and cruise ok-ish. so i limped it home. i just jumped in my truck and went to work, didnt have time to mess with it. sat for a week or two... i was fairly certain it just wiped all those steels clean. in that time i started looking to see what rebuild/replace was going to cost, 10l90 swap maybe (still a maybe). got around to actually diagnosing. made sure fluid level was good, had a bunch of codes but they were all for like tpms and wheel speed sensors, loss of communication with some module basically threw the trans into limp mode cause it wasnt getting speed signal 🤦‍♂️. i checked over all the harnesses, connectors, harnesses around the headers, inside the wheel wells. couldnt find anything so just rare fluke occurrence at this point i guess. cleared the codes, still makes same sloppy 4>5 shift

next immediate mod:
DSX port controller and dual wideband set up has been ordered (the port rails, plumbing, and injectors have been installed for a few months now).
was going to just order the controller and tune it off the wideband i already have same way it would normally. however, with the additional dual widebands, the controller will provide closed loop fueling 100% of the time via the port injection and will also compensate for bank to bank inconsistencies independent of each other. much of tune needs to be gone back through, rail pressure on the high side wasnt just dropping in high rpm, some wot launch/downshifts got lightened up. so hopefully can feed some power back in those areas.

for those not quite on the mod path yet... while i would say the port injection does have more potential - with what ive now spent on plates/injectors now controller and widebands, going thpsi wouldve been a little bit cheaper. part for part i would be in it around the same cost as a cam/30% injectors. labor if i was paying someone to do it would be more but the setup wouldve been simpler.

 

[CTVTinoco]

Were you using the Katech Dual-Pump? I was having issues with that pump as well and just switched over to the DSX dual pump, which seems more robust and I have also heard great things about it. I am also planning on going the DSX port direction as I now have +30% XDI and Lingenfilter HPFP.

 

[randeez]

Were you using the Katech Dual-Pump? I was having issues with that pump as well and just switched over to the DSX dual pump, which seems more robust and I have also heard great things about it. I am also planning on going the DSX port direction as I now have +30% XDI and Lingenfilter HPFP.

Yea, still using the katech drop in (DW400s). When i went looking, Katech was the only option. I picked up the vaporworx controller before katech started providing it as a package - I do like how simple of a solution it is to control the second pump. between the pumps and controller the price is pretty much the same as DSXs which comes pumps and controller all together
i think i read DSX uses twin hellcat pumps?? they should be able to provide more fuel and imo be more reliable. not sure what he's doing to control the second pump but i believe its also pwm controlled?
i havent really had problems with the DW400 pumps themselves, its just been the plumbing mostly. which looking at the DSX theres a billet block that the pump discharge connects to and then out of the hat. that is nice and solves a lot of problems. the fixes for this pump setup have been cheap, its removing the tank to do them that is getting old quick

 

[CTVTinoco]

Yea, still using the katech drop in (DW400s). When i went looking, Katech was the only option. I picked up the vaporworx controller before katech started providing it as a package - I do like how simple of a solution it is to control the second pump. between the pumps and controller the price is pretty much the same as DSXs which comes pumps and controller all together
i think i read DSX uses twin hellcat pumps?? they should be able to provide more fuel and imo be more reliable. not sure what he's doing to control the second pump but i believe its also pwm controlled?
i havent really had problems with the DW400 pumps themselves, its just been the plumbing mostly. which looking at the DSX theres a billet block that the pump discharge connects to and then out of the hat. that is nice and solves a lot of problems. the fixes for this pump setup have been cheap, its removing the tank to do them that is getting old quick

Gotcha. Yeah I kept having issues with mine and had the pump tested as well as the controller but everything kept coming back good, though my pressure was still not going above 50PSI. The system had worked well for about 4-months without issue until it I started seeing the PSI issues. The DSX pump uses the OEM module but replaces it with DSX's, they use the same casing for the factory PWM. Definitely a nice unit.

 

[randeez]

Gotcha. Yeah I kept having issues with mine and had the pump tested as well as the controller but everything kept coming back good, though my pressure was still not going above 50PSI. The system had worked well for about 4-months without issue until it I started seeing the PSI issues. The DSX pump uses the OEM module but replaces it with DSX's, they use the same casing for the factory PWM. Definitely a nice unit.

i would say good chance you had similar leak in bucket, we dont get to see pump duty cycle anymore. it would be a an easy indicator that pumps are working way to hard to not build any psi.
also good chance i'll be going to the dsx in tank also if i have to drop tank again anytime soon

dsx port controller was finally available at the beginning of the year, got it ordered and in.... just finishing up the installation with dual widebands, installation was as fool proof as it could be imo. ended up pulling a dumbass and googled the wrong E92 ecu pinout (ls1tech failed me again). breezed thru the install and had problems i chased for a couple days before i found the correct pinout. i think its all done and correct, i have a few other things to finish up and its been raining for the past week so havent been in much of a hurry. have only started and idled, everything showing up in the scanner.

 

[Katech_Mike]

Someone just sent me this thread.

Please reach out to me if you have a Katech module that will not hold pressure.

mike@katechengines.com

 

[CTVTinoco]

i would say good chance you had similar leak in bucket, we dont get to see pump duty cycle anymore. it would be a an easy indicator that pumps are working way to hard to not build any psi.
also good chance i'll be going to the dsx in tank also if i have to drop tank again anytime soon

dsx port controller was finally available at the beginning of the year, got it ordered and in.... just finishing up the installation with dual widebands, installation was as fool proof as it could be imo. ended up pulling a dumbass and googled the wrong E92 ecu pinout (ls1tech failed me again). breezed thru the install and had problems i chased for a couple days before i found the correct pinout. i think its all done and correct, i have a few other things to finish up and its been raining for the past week so havent been in much of a hurry. have only started and idled, everything showing up in the scanner.

Looks like Katech is able to help rebuild these/knows the issue so hopefully you can get that sorted. Good to see they'ew willing to help.

I am also looking into the DSX Atlas controller but I already have XDI +30% and the Lingenfilter HPFP. DSX said they recommend using the stock injectors as they play nicer with their controller - so I'll probably keep mine and wait until I go 2650 to make that jump.

 

[randeez]

Looks like Katech is able to help rebuild these/knows the issue so hopefully you can get that sorted. Good to see they'ew willing to help.

I am also looking into the DSX Atlas controller but I already have XDI +30% and the Lingenfilter HPFP. DSX said they recommend using the stock injectors as they play nicer with their controller - so I'll probably keep mine and wait until I go 2650 to make that jump.

as much as i appreciate katech, i dont think they want mine back lol it has been working well lately however, when it works it works
i think im sitting on like 73% ethanol at the moment, im using stock gm truck flex fuel injectors(54lb) ive seen as high as about 40% IDC on them and the katech is holding 80psi steady
i think the atlas controller is very dependent on the tune being spot on as far as DI injectors, i can say watching the scanner fueling basically runs DI up to 25%idc@6ms then you start seeing PI come in, but im sure its a whole lot more complicated than that. you dont really tune anything in the atlas, just set the injector data(has a few already in drop down menu and where you want to eq to target)
ported blower/103mm is up next, not sure if im going to hold off for a while tho

 

[randeez]

feel like a dsx fanboy at this point, but the parts are nice.
fuel module, twin walbro ti295 pumps 535lph(?) each. billet bucket, billet hat, billet manifold, retains venturi function, has an 8an port for return thats blocked off if thats how you want to run it
kit comes with second fpcm, complete wiring harness to integrate, .htt file to change all the tables that need changed in the tune, the 2pin connector in the pics below is just for the level sensor, just depin the oem connector and pin the one they provide
the unit itself is still very bulky, without the flexible hoses it seems easier to install however - could just be that ive taking it out and put it in a handful of times now.
i did want it with an -8an on the hat, but the tube inside the tank is also only 3/8 so from a flow perspective wouldnt have made much difference
these pumps have no internal checkvalve so they need to both be ran full blast with return or both by pwm and the second fpcm.
i did install the lingenfelter high flow check valve - Direct Injection High Flow Check Valve Assembly under the car. not sure if i would have any priming/starting issues but i've had it sitting around for a couple months and was waiting for parts to show up anyway.
noticed one of the rear o2 bungs had a bit of soot around the base (where the widebands are currently) like it just didnt penetrate the tubing. so i wirebrushed/cleaned the hell out of it inside and out and ran tig welder over it with a little more filler to hopefully seal it up.
had a couple of broken bolts for some of the undercarriage plates, i was able to just drill and extract them and replace with some new hardware.
the clips for the plastic fuel/vent hoses, i lost one completely somehow and had another that broke one side off of it so it barely worked. i dont think GM sells us the clip so you have to buy the entire hose. plowed thru abunch of google pics and took a chance ordering some dorman plastic hose ends that had what looked like the correct clip and got lucky with these for the 3/8 vent tube that runs over the tank (and should also fit the oem fuel line from the tank if needed)the red clip: Amazon.com

 

[randeez]

not much of an update but need some motivation/accountability
after swapping in the new dual bucket, immediately went on a little road trip about 500mi round trip. filled up with 93oct to get a little more mpg out of it everything seemed to run fine but felt down on power, assuming it was just because i had been running it almost only on straight E85 and that little lack of timing wasnt really as bad as it felt to me. BUT on the return trip home I did a quick data log... fuel pressure was dropping to crap, like only a single pump running kind of pressure. sort of luckily, i guess, i was on 93oct and not e85, or it would have really of taxed a single pump. not sure if it just didnt like running for hours on end or what, checked everything over, rechecked all connections, tested out pumps, it hasnt happened since (few months) but still is a concern. having an issue now where every once in a while it wants to just run 72psi all the time and not ramp down to the commanded at idle/low flow, so going to check it all over one more time and try and figure that out.

im not a fan of gauges but wanted something i could easily watch with having to data log or use a bluetooth app to monitor stuff. sooo went ahead and added P3 vent gauge, it doesnt have anything native to watch fuel pressure, so i had to use one of the analog configurable inputs to another fuel pressure sensor i added to the end of a port injection rail.
the other analog input (has two total) i am trying to get a temp sensor in the sc coolant reservoir to watch that temp. the gauge is looking for a 0-5v signal though and most temp sensors (gm anyway) are just a resistor style and not linear - i've tried a few sensors with a "fast" converter to 0-5v but getting it any kind of accurate across the range is way off. i think i found an "active" linear sensor that will work, went ahead and ordered it to try out.

sc coolant hoses.... have kind of bothered me running over the intake tube. when i had shop do it, it was probably the logical way to do it so i lived with it, till now anyway. started re routing them, knew kong had a new coolant manifold out that i wanted to use eventually. was just going to make the hoses and hope i could use them later but went ahead and ordered the manifold to just make the hoses once. i was able to route them slightly back, under the tube, and one along side/one under the rotofab "housing"

 

[randeez]

Pretty sure we got the fuel system sorted out. I reached out to DSX, as I had a wideband controller go out. Started talking about the fuel system, he mentioned a few people had similar issure where a retaining plate at the bottom would distort under high pressure. And cause pressure to fluctuate. So he updated the plate, made it out of stainless, added ribs to stiffen it. Also mentioned the venturi hose could cause the issue I was having. So he sent out the new plate and o2 controller and I ordered another set of venturi hoses since tank was coming out anyway. Dropped tank for the hundreth time, Got it all swapped out, pressure is a lot more stable
Also along the way, it was breaking up under wot, I had assumed it was fuel issues so I was trying to get that squared away. Logging misfires made it very apparent it was cyl 6 with a couple hundred. Tried the ol' new coil, sparkplug, and plug wire and it , surprisingly, cleared right up. plug wire just fail, created a little blister on the wire, like an inch from the coil no where near anything, not rubbing anything, far away from heat.

Really needed to get back to performance mods... but deal came up.
10l90/converter out of a 2021 zl1, not even 3200miles on it
Had a friend go scoop it up this morning.

 

[Pb82 Ronin]

Pretty sure we got the fuel system sorted out. I reached out to DSX, as I had a wideband controller go out. Started talking about the fuel system, he mentioned a few people had similar issure where a retaining plate at the bottom would distort under high pressure. And cause pressure to fluctuate. So he updated the plate, made it out of stainless, added ribs to stiffen it. Also mentioned the venturi hose could cause the issue I was having. So he sent out the new plate and o2 controller and I ordered another set of venturi hoses since tank was coming out anyway. Dropped tank for the hundreth time, Got it all swapped out, pressure is a lot more stable
Also along the way, it was breaking up under wot, I had assumed it was fuel issues so I was trying to get that squared away. Logging misfires made it very apparent it was cyl 6 with a couple hundred. Tried the ol' new coil, sparkplug, and plug wire and it , surprisingly, cleared right up. plug wire just fail, created a little blister on the wire, like an inch from the coil no where near anything, not rubbing anything, far away from heat.
View attachment 179593


Really needed to get back to performance mods... but deal came up.
10l90/converter out of a 2021 zl1, not even 3200miles on it
Had a friend go scoop it up this morning.
View attachment 179592

That's awesome that she's driving better now. I'm super eager to hear/see your results with the 10 speed. I was thinking of doing that very same mod.

 

[randeez]

That's awesome that she's driving better now. I'm super eager to hear/see your results with the 10 speed. I was thinking of doing that very same mod.

spoke too soon... theres something my car doesnt like about having the second FPCM to control the 2nd pump.
first start in the morning everything runs great, i have +/- hour drive to office so its usually my shakedown run. everything works for that entire time, fuel pressure pid follows very closely, nearly no correction needed.
I'll stop and grab breakfast or something. restart it 10 min later and everything goes to shit, fuel pressure acts like its only on one pump (and dumb on my part) i elected for pumps with no check valve. so if only ones working its pretty much blowing thru the other and i have 20-30psi of fp with the pump forcing 100% duty cycle. and intermittently the second pump comes on, pwm calling for 100% so then fuel pressure shoots up to 110psi, by the time fpcm corrects and brings pressure down second fpcm shuts down again and back to 20psi of pressure. rinse repeat.
so got home yesterday after stressing about it all day; ripped the second fpcm out, put the vaporworx controller back in and wired it to the second pump - i liked the simplicity of the vaporworx controller, its rated for 40amp continuous, power to it - power to pump and a single wire for control, and i never had an issue with it. may be a little more crude than the second fpcm but it was dead on reliable before, and i can jump across it, worst case scenario, to hotwire the pump if have to limp home
it was late by the time i got done, i just started it up and fuel pressure was exactly where it should at start up and then came down to correct at idle/warmed up. really need to drive it for some extended amount of time and make sure its all happy again.
if this doesnt fix it, guess im moving onto return system cause im about sick of messing with it.

and put in the order for the powertrain swap solutions 10sp swap kit. talking with the few tuners i know, they havent noticed any shortcomings with the kit, all functionality is retained. trying to do it all natively with oem ecm/tcm, repinning plugs, changing vins etc isnt as straight forward as i thought

 

[Pb82 Ronin]

spoke too soon... theres something my car doesnt like about having the second FPCM to control the 2nd pump.
first start in the morning everything runs great, i have +/- hour drive to office so its usually my shakedown run. everything works for that entire time, fuel pressure pid follows very closely, nearly no correction needed.
I'll stop and grab breakfast or something. restart it 10 min later and everything goes to shit, fuel pressure acts like its only on one pump (and dumb on my part) i elected for pumps with no check valve. so if only ones working its pretty much blowing thru the other and i have 20-30psi of fp with the pump forcing 100% duty cycle. and intermittently the second pump comes on, pwm calling for 100% so then fuel pressure shoots up to 110psi, by the time fpcm corrects and brings pressure down second fpcm shuts down again and back to 20psi of pressure. rinse repeat.
so got home yesterday after stressing about it all day; ripped the second fpcm out, put the vaporworx controller back in and wired it to the second pump - i liked the simplicity of the vaporworx controller, its rated for 40amp continuous, power to it - power to pump and a single wire for control, and i never had an issue with it. may be a little more crude than the second fpcm but it was dead on reliable before, and i can jump across it, worst case scenario, to hotwire the pump if have to limp home
it was late by the time i got done, i just started it up and fuel pressure was exactly where it should at start up and then came down to correct at idle/warmed up. really need to drive it for some extended amount of time and make sure its all happy again.
if this doesnt fix it, guess im moving onto return system cause im about sick of messing with it.

and put in the order for the powertrain swap solutions 10sp swap kit. talking with the few tuners i know, they havent noticed any shortcomings with the kit, all functionality is retained. trying to do it all natively with oem ecm/tcm, repinning plugs, changing vins etc isnt as straight forward as i thought

Dang man...that's a large uncertainty volume. IMO I wouldn't do the 10spd swap until the car was reliable and consistent. No need to start wondering if your brand new trans swap is adding to the current issues. That sounds like a recipe for pre-adult hair loss (translation: a bad few years).

 

[randeez]

I like the abuse

 

[randeez]

i was left unsupervised for too long over labor day weekend.

went ahead and swapped out the fuel pumps... kinked that chintzyass plastic fuel hose coming off the tank right where it reconnects. not sure if maybe someone had already done it before me cause i wasnt forcing it or anything. either way i barely trust it as it is so i ordered a new one - may try and change it over to an/hard line (again) but its just an awkward piece that includes the fuel pressure sensor and quick connects.
i rushed ordering the PSS swap kit because i heard they could take a few weeks to get the order out, ordered and delivered in like 3 days. the PnP nature of it i think it going to annoy me, mostly because it basically just leaves the 8sp connector wiring in the car. depending on how anxious i am to get it all back together i may strip it out of the harness after i make sure everything works
since i had the exhaust and driveshaft out anyway - i went ahead and started the 10speed swap. 8speed is like 98% ready to come out, only thing holding it in is the mount for it. my transmission jack is toast i havent used it in years so i had to order a new one i could prob get it out with a floor jack and not give a shit about it, but would still need to put in the 10l90. pulled the wiper cowl to get to the top bellhousing bolts....i may end up re doing some of the fuel distribution and a few things while its all open and accessible behind the supercharger, but that led to another distraction...
the mighty mouse catch can needs to blockoff the valley cover opening, so i pulled the supercharger (really just needs to be loosened and lifted up a few inches) but since i was there anyway i pulled it off completely. prob shoulve done catch can a long time ago, a little oily inside but not worst ive seen. getting sent out for kong xport and 103mm.

 

[CTVTinoco]

Nice build, man! i am wondering if you've had any hot start issues, as I developed one with similar mods with me running port injection on Atlas

 

[randeez]

Nice build, man! i am wondering if you've had any hot start issues, as I developed one with similar mods with me running port injection on Atlas

this from a few posts up is about the extent of what i had problems with, not really a tuning issue my fuel pressure was just crap ~20-30psi at hot restart:

"I'll stop and grab breakfast or something. restart it 10 min later and everything goes to shit, fuel pressure acts like its only on one pump (and dumb on my part) i elected for pumps with no check valve. so if only ones working its pretty much blowing thru the other and i have 20-30psi of fp with the pump forcing 100% duty cycle. and intermittently the second pump comes on, pwm calling for 100% so then fuel pressure shoots up to 110psi, by the time fpcm corrects and brings pressure down second fpcm shuts down again and back to 20psi of pressure. rinse repeat."

I thought it may be because of the twin fpcm, one of them faulting or not communicating or something. i removed the second fpcm and put the vaporworx back in to control the second pump and the problem was "fixed" > ie no more hot start problems, BUT i noticed my fuel pump duty cycle way high just at idle and cruise (65%+) just to maintain ~50psi with zero engine load. WOT had great pressure, and i probably couldve left it for a while and been fine.
can only speculate at this time but im thinking the twin fpcm was probably fine and the pumps may have been the problem. going bad or sucked up some debris maybe - after running the pumps for a while (daily commute is hour+) exacerbated the issue. putting 12v on them now on the bench they "work" fine, you can move the impeller without much resistance, but im thinking the low PWM signal had a hard time getting them spinning.
pumps are now swapped, but wont know if its fixed till it gets put back together - aside from obviously providing sufficient fuel WOT, that would be seeing the duty cycle for the fuel pumps back down around 30% with little to no load to know that there arent any underlying problems

 

[CTVTinoco]

this from a few posts up is about the extent of what i had problems with, not really a tuning issue my fuel pressure was just crap ~20-30psi at hot restart:

"I'll stop and grab breakfast or something. restart it 10 min later and everything goes to shit, fuel pressure acts like its only on one pump (and dumb on my part) i elected for pumps with no check valve. so if only ones working its pretty much blowing thru the other and i have 20-30psi of fp with the pump forcing 100% duty cycle. and intermittently the second pump comes on, pwm calling for 100% so then fuel pressure shoots up to 110psi, by the time fpcm corrects and brings pressure down second fpcm shuts down again and back to 20psi of pressure. rinse repeat."

I thought it may be because of the twin fpcm, one of them faulting or not communicating or something. i removed the second fpcm and put the vaporworx back in to control the second pump and the problem was "fixed" > ie no more hot start problems, BUT i noticed my fuel pump duty cycle way high just at idle and cruise (65%+) just to maintain ~50psi with zero engine load. WOT had great pressure, and i probably couldve left it for a while and been fine.
can only speculate at this time but im thinking the twin fpcm was probably fine and the pumps may have been the problem. going bad or sucked up some debris maybe - after running the pumps for a while (daily commute is hour+) exacerbated the issue. putting 12v on them now on the bench they "work" fine, you can move the impeller without much resistance, but im thinking the low PWM signal had a hard time getting them spinning.
pumps are now swapped, but wont know if its fixed till it gets put back together - aside from obviously providing sufficient fuel WOT, that would be seeing the duty cycle for the fuel pumps back down around 30% with little to no load to know that there arent any underlying problems

Interesting. This is all helpful and adds to my suspicion that it is fuel-related, which is why I asked. I am thinking of checking my check valve or tuning my pumps to be on at all times, or having them prime for longer.