What would cause my car to run (when it does) pig rich. My piping came apart on my s/c last Sat. now my car will only run after cleaning the plugs and with the bap fuse out. It will start and run if you keep your foot on the gas at least 2k rpm as soon as you let off the the car dies. Black soot is all over the tail pipes and when you pull the plugs after running for just a few mins. at 2k rpm or more they are black with soot and gas. I have un-hooked the battery and re-loaded the tune nothing helps. Like I said the only way it starts is after cleaning the plugs, removing the bap fuse and keeping the rpm's at least 2k. My tuner said the bap don't act this way, but then why will it only start with the fuse removed but still run pig rich. The car was running perfect before the connection came loose. I have checked every connection to the s/c they are all connected and tight. Could I have fried my pcm ? Since my tuner is 4hrs. away and I have no way of getting the car to them, I have no choice but to take it to the dealer, and of course pay big time. I talked to the service manager and he assured he had some one he felt confident in looking at it. But just wonder if anyone on the forum might have an idea.

 

Let me make sure I understand everything completely. The piping that came apart; do you mean a loose clamp or boost caused the pipe between the blower and TB to come off? Do you have an in-line air-to-air IC? Were you under boost at the time?

I'm not familiar with the Paxton setup. Is the MAF upstream or downstream of the blower?

Also, how do you have the BAP connected? Does it turn on at 3-psig boost via the supplied Hobbs switch or do you have it continually working (not using the Hobbs)? Also, when it does work, where do you have the rotary **** set at?

Without knowing the answers, I'm suspecting the MAF was blown out or a small chance there is an injector problem...

 

Yes I was under boost, I do believe it was a loose clamp I found it laying in the road were it happened. The Maf is near the air filter. The rotary **** is in the trunk and is set at 50; I believe its always working, I don't know of any Hobbs switch. I was also thinking of the blown maf.

 

I have a sneaky suspicion that it's your MAF. I burned up my MAF once during a burnout. When I released my line lock and let up on the gas, the engine died and would not restart....

I think datalogging MAF airflow values will aid in diagnostics but not positive as I've never done this on this car. Is this possible?

I believe the reason why the engine won't even start when the BAP fuse is in is because it's set at maximum voltage (50 on the ****). Even without it, you're running pig rich. With it, it's even worse, probably so bad that it won't start....

Do you have the 20 or 40-amp BAP? I have a 40 and it uses a Hobbs (vacuum / pressure) switch. See attachment.

Willie

 

just curious- if the tube came off under boost, at heavy throttle, would it cause the engine to run lean due to intake being wide open, or would the MAF stilll be showing high airflow due the the suction side of the compressor?

seems like if tube on suction side of supercharger came off, things could go dangerously lean- but if the pressure side popped off(most likely to blow off) that It would just think it was full throttle even after backing off the throttle due to the suction and keep pouring the fuel...just curious if anyone else thinks a loose suction side tube might result in severely lean run...

hopefully just burnt the the MAF- isnt there a way to read the output voltage with a voltmeter to see if its 'stuck' or open circuit?

 

I believe I have the 20 amp., but I'm not real sure.

 

I appreciate any other suggestions, I miss drivng my stang.

 

Can you datalog? It will tell us what your MAF voltage is.

Willie