Ran the old fuel down to about 1/8 tank and filled up with fresh fuel. No change. Never put any cleaner in.
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Hot start issues
Hi folks, I’ve got a cammed, full bolt on V2 experiencing hot start issues. Cold starts are crisp and instantaneous. Hot starts are quite the opposite. Car sputters and stalls out. I have to apply throttle to get it to fire. I suspect this is a tuning issue? Cranking air/fuel needing adjustment? This just randomly started relatively recently, wasn’t doing it previously. Please advise, thank you.
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Since you don't have hpt, you should get that app, Torque I believe it's called and the little Bluetooth dongle. When I had an injector failure years ago I went down similar road; plugs, wires, o2 sensors, coil packs etc. I was logging every time I tried to start it after I did each remedy. Besides the misfires which helped me locate the problem cylinder, the o2 sensor on bank 2 was way off compared to bank 1. Took a closer look at the data and bank 2 was rich when the motor wasn't running and that along with everything I'd done so far pointed to an injector hanging open.
In short, get the app and log some of these parameters on start up. Its also something you can use to read future engine codes on all your vehicles.
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In short, get the app and log some of these parameters on start up. Its also something you can use to read future engine codes on all your vehicles.
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I have a similar issue... cold start it fires right up. But when it's warm/hot, it will crank and crank and finally fire. Sometimes after I apply throttle. My 2012 V had some work done before I bought it - CAI, E85, injectors, bigger HX, reinforced brick, second cat delete, 3" exhaust to Borla mufflers and tuned. When I ran E85 last year, it started misfiring when idling for periods of time (like at the bank). I stopped running E85 and ran SeaFoam and that helped. But every once in a while it would misfire again and I would have to add more SeaFoam (usually 6-7 tanks later). Misfire always started on # 4, so I changed plugs thinking they might have been an issue as I'm at 115,000 and don't know the service history. That didn't change anything. I had been told by several people that it might be the tune - still could be - but one day I hooked my scanner up while I had an issue and watched the fuel pressure. When I shut it off, the pressure dropped from 56psi to 35psi in less than 2 minutes and all the way down to 14psi in 5 minutes. I'm guessing #4 injector has a leak and "floods" that cylinder making it hard to start when hot. I plan to have my injectors cleaned/rebuilt when I park it to replace front control arm bushings.
I have a tendency to prime the fuel pump before starting. I stopped doing that and it hasn’t done it since. Could be just a fluke who knows?
fuel pressure should leak down they do that slowly on purpose, even if its at 0 pressure but the line is full thats all it needs as the pumps priming instantly add pressure, another thing is if it takes a little throttle to get it going then it either needs more throttle in startup tables or the fuel is too rich, sometimes less fuel helps or more throttle, or if u use throttle and its worse then it prob needs more fuel as more throttle would just make it leaner so then adding fuel should help, ethanol cold starts ive found like to dump alot of fuel on the cranking but then when fires only 0-5% richer for a running engine, too rich warmup running engine just takes longer to heat up with ethanol, 1.0-0.95 lambda on the wideband is fine for ethanol cold warmup running, and sometimes lower cranking timing esp if u have a camshaft, hot starts the same just with less cranking fuel to start with
^ lot of good info. Im still thinking injector man. The whole throttle to let more air in bc you're rich and what not...
How does it respond when you remote start it? Also, if you press the pedal to the floor when you start it, it closes the injectors until it cranks obviously and then you get off it quick. Little trick i learned when dealing with this myself. Might be worth trying that; pedal to floor, prime ignition, crank and let off. You mentioned the not priming it helps, def another test you could run to isolate it. I think an injector is starting to go bad and just hasn't completely failed yet.
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How does it respond when you remote start it? Also, if you press the pedal to the floor when you start it, it closes the injectors until it cranks obviously and then you get off it quick. Little trick i learned when dealing with this myself. Might be worth trying that; pedal to floor, prime ignition, crank and let off. You mentioned the not priming it helps, def another test you could run to isolate it. I think an injector is starting to go bad and just hasn't completely failed yet.
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It’s manual I can’t remote start.
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21 - 27 of 27 Posts
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