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Discussion Starter #1
To run E85 just installed AEM pumps, flex fuel sensor. and ID 1050 injectors. After 3-4 logs did WOT in second gear from 35-40 mph. Went to about 6000 in second and felt like it hit a rev limiter. After playing the log back very slowly.
Fuel pressure starts at 36, drops to 27 as soon as the pedal goes down, up to 42 very briefly, down to 28-30 psi from 4800 -6000 rpm. Fuel pressure does not even start to come up?

Pumps were installed slowly and carefully. Anyone have any thoughts ?


Already had a BAP installed w/ Hobbs switch and a tee in the line from passenger side port in supercharger to solenoid X line. Worked well before. Part of the lines with the tee in it were off to do the injectors. Tool a quick look seems ok. Maybe line slightly kinked, pressure not getting to solenoid? If in fact this has some control on fuel pressure? Will put original line back on and remove the tee to rule this out. Seems like a reach.
 

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Did you use 2 O-rings per pump? That's really low pressure. I'd have to look at a log but if I remember correctly, I have around 60+psi with the same pumps and it holds steady at WOT with no BAP. Kinda seems like one of the pumps is bad or not getting power.

Probably deserves a kick in the nuts for asking but you did retune for the injectors didn't you?
 

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Discussion Starter #3
Did you use 2 O-rings per pump? That's really low pressure. I'd have to look at a log but if I remember correctly, I have around 60+psi with the same pumps and it holds steady at WOT with no BAP. Kinda seems like one of the pumps is bad or not getting power.

Probably deserves a kick in the nuts for asking but you did retune for the injectors didn't you?
Just checked my pile of parts, I also had a complete used unit. I used the white spacer from the original pumps and the original o-ring as the AEM o-rings had a smaller inner diameter and
smaller outer diameter. So I used one o-ring and one spacer per pump.

Yes I am working with a remote tuner, and tuning for the new injectors. Runs great until WOT. No CELS from pumps or anything else?
 

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For some reason I remember 2 O-rings per pump.
 

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Discussion Starter #6
It does show 2 for sure, they are DW's but look the same as AEM or stock. The stock ones appeared to use only one. I remember looking into the housing for the other o-ring after pulling the stock pumps, even taking a pick to pull it out, and was not there.

So you used the 2 o-rings plus the white spacer??
 

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Yes I used 2 plus the spacer
 

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Discussion Starter #8
Yes I used 2 plus the spacer
Thanks Jim. After looking at all other possibilities I think you may be right. Took a stock pump from my pile of parts and w/ 2 o-rings and spacer and it easily goes back into the housing
and clips into place. Pumps back out. Need to drain or siphon 1/2 tank of fuel. Snow rain and freezing rain today and tomorrow. Thanks again!
 

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What is your commanded fuel pressure? Did I miss that in original post?


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Happy to be able to help and trust that fixes your problem.

Why do you need to drain or syphon the fuel? I feel for ya with the crappy weather. A friend in Appleton Wisconsin called this morning and said they have 20 inches of snow now! It will be 80 here today.

Best of luck to you!
 

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I only used the spacers and original O-ring (one per pump) and no issues.
 

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I used 2 o-rings per pump as I followed the video above for instructions on R&R. He mentioned to use 2 or you wouldn't get good pressure. His set of instructions were for the dw pumps though but worked perfectly for me.
 

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Discussion Starter #13
What is your commanded fuel pressure? Did I miss that in original post?
Not sure car is being remote tuned. Same tuner as last year.

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Happy to be able to help and trust that fixes your problem.

Why do you need to drain or syphon the fuel? I feel for ya with the crappy weather. A friend in Appleton Wisconsin called this morning and said they have 20 inches of snow now! It will be 80 here today.

Best of luck to you!
Easier to pull the bucket in and out w/ less fuel. Pulled 8 gallons out through the fuel rail. Have not pulled the pumps back out yet.

I only used the spacers and original O-ring (one per pump) and no issues.
No you got me wondering, if not the absence of the single O-ring? Where else do I look ? Can the pumps be bench tested?
 

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Test them for resistance with an ohm meter to make sure they read the same. I feel pretty confident you'll get the pressure back with the 2 O-ring setup. I know it's not a DW pump but if you watch the entire video posted above, that guy makes mention of using 2 O-rings to hold the pressure. Who knows - maybe one of your single O-rings got rolled or pinched.
 

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Discussion Starter #15
Test them for resistance with an ohm meter to make sure they read the same. I feel pretty confident you'll get the pressure back with the 2 O-ring setup. I know it's not a DW pump but if you watch the entire video posted above, that guy makes mention of using 2 O-rings to hold the pressure. Who knows - maybe one of your single O-rings got rolled or pinched.
So finally got the pumps out last night. Found one pump had pulled out slightly from the white bracket clip on one side. The other side was still holding it in. Thought this would be it, pulled both pumps, and put 2 O-rings on each pump. No kinked lines everything else looked good. Same issue wiil hold 65-70 psi fuel pressure at 40% throttle in 2nd gear 3-5000 rpm. Going 80% throttle 2nd gear 4-6000 rpm drops to 30 psi. ???
 

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Beats me. Seems like you're getting good pressure now whereas before in your op, it appeared your max was 40ish.

If your BAP was good before, I can't see that causing it.

Can you post a log file?
 

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Discussion Starter #17
Beats me. Seems like you're getting good pressure now whereas before in your op, it appeared your max was 40ish.

If your BAP was good before, I can't see that causing it.

Can you post a log file?
At 80 % or WOT throttle it drops immediately, same as before. Pressure will stay up at part throttle when you start to get on it. Thinking the venturi or jet pump part is not working, and bucket is being emptied. This is not my original pump module, mine was leaking at the line fitting. The used one I bought was a from a 2012 w/ over 100,000 miles, and then swapped the AEM's into this one.
 

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Was the used pump module working with the stock pumps? I may have a pump assembly in my spare parts you could try but I would think the module you're using would be good.

Does it drop at 80% throttle below 4k? Could it be tune related? ??

Whats the log file look like?
 

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Is the crossover tube connected correctly to the bottom of the fuel pump bucket assy? If it's not pushed on fully or fitting/oring may not be sealing perfectly then the pumps won't remain submerged in fuel. Also if the bucket isn't clocked correctly the springs may not keep it submerged all the time.

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Discussion Starter #20
Was the used pump module working with the stock pumps? I may have a pump assembly in my spare parts you could try but I would think the module you're using would be good.

Does it drop at 80% throttle below 4k? Could it be tune related? ??

Whats the log file look like?
Not sure if the used module was working, just pulled the stock pumps out and put AEM's in and installed. At WOT throttle it drops as soon as you floor it. Would not think tune related. it does hit 70 psi at lighter throttle settings. I will get a log up later on.

Is the crossover tube connected correctly to the bottom of the fuel pump bucket assy? If it's not pushed on fully or fitting/oring may not be sealing perfectly then the pumps won't remain submerged in fuel. Also if the bucket isn't clocked correctly the springs may not keep it submerged all the time.

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Yes the crossover tube was on all the way, definite audible click on install both times and would not pull back off after hearing click. Fitting seemed to seal, felt solid and not loose. Bucket is clocked correctly. It was marked on first removal, as was the fuel line.

Thinking the venturi pump is the only thing left. I believe it also keeps that small trap door at the bottom of the bucket open as well. May just start w/ a new module at this point. Knowing the original stock module and pumps w/ BAP at 15.2 volts went 133 mph w/ good fuel pressure.
 
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