I can't win with this car. So. Pretty sure this is my fuel pump but wanted to float it past you all first. Car starts strong, idles for 4-5 seconds, stalls out. No change in idle time between attempts. Full tank of gas. Over the past week or two I've noticed a loss of power at wot between like 4K and 6k rpm's. I'm thinking this all points to one of the two fuel pumps quitting. Exhaust smells really rich. Another curiosity though, tried to log the few seconds of run time and every time I start the car the Cobb loses its connection. Any ideas?

 

Are any codes stored?

 

Didn't think to check, I was late for work this morning.

 

You checked the air filter and pipes connecting the maf's?. How is your boost level. Just a shot in the dark.

 

Air filter was changed in December. I'll check the pipes after work. Boost was fine yesterday, can't build boost quick enough before the stall happens.

 

It's the rich exhaust thing that doesn't make sense.Do you have an obd reader besides the cobb unit?

 

All I have is the cobb.

New updates though. Got some logs, no stored codes. I plugged in a batt tender and reflashed the tune, the car idled a smidge rough but strong and lasted probably 3-4 minutes. I unhooked the tender, waited, hooked it back up, engine stalled out maybe a minute later. After the reflash the exhaust cleared up some of its richness but still had a hint of rich.

 

Did you run the car without the tune? Try going to stock and check it. You can also try re downloading the tune from cobb. The file may be corrupted. The tune tends to bring otherwise unnoticeable problems to light. Like a weak maf signal or other components.

 

So I flashed stage 0 back on and it tried to stall out the same as the tuned map but caught itself a few times and then started running like normal. Stage 0 should run rich on my car as I have 1000cc injectors (no other mods, long story). Flashed back to tune and no change. So something about stage 0 allows it to power through the stall attempts and then level out.

 

The injectors are a pretty big piece to the puzzle. I would say that's going to be at least part of your problem. Is the cobb tune your using made for those? You really need a data log showing what's going on with fueling. I may be way off but if it was my car I would start there. Take a good look at the engine also to make sure nothing came off or loose. It was obviously taken apart or dropped to do the injectors.

 

The tune is custom (done on dyno) to this car. It's been working well since December. I have a bunch of logs that I sent over to Cobb and my tuner, awaiting feedback. Right now I'm kind of just trying to figure out if I should tow it to the dealer or see if a tune tweak can fix it (doubtful).

 

In that case I would do a thorough check of all air inlet spots. It must be getting unmetered air or your maf's are an issue. Is it a mafless tune? The ecm is not doing it's thing due to something being different in the scenario. Is this an e85 setup? if so then maybe your pumps are messed up like you first thought. I'm sure mitch will figure it out.

 

I don't know enough about the tune to know if it's maf-less or not. I know it's base tune is a stage 3 modified on the dyno for less bolt on mods. No e85.

I checked the engine for obvious signs of something out of place but I deff don't know everywhere to check.

 

So the COBB unit doesn't see any codes when you read the ECU or you don't see a check engine light on? You can log with COBB even before starting the car. Turn the key to on, wait for the dashlights, select log feature in AP, start logging, start car, stop logging right before the minute is up since you said it runs for a minute. That should help your tuner know what's going on. Have you checked your FPR vacuum line at both the FPR and plenum feed? Do you have the original copy of the custom dyno tune? If so, try deleting the tune from the AP itself and readding the original copy back to the AP and flash that tune back on the car.

It sounds like it's fuel related in someway. Odd part is that you mentioned it's been running fine since December.

 

Figured it out, fuel pump 2 went bad. Pulled the fuze for 1 and she died almost immediately. Pulled the fuse for 2 and she's running fine. Thanks for the input everyone!

Now does anyone know if I can buy just one pump or do I have to replace the whole fuel basket assembly?