Engine is loading up with fuel causing it to bog...
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
Engine is loading up with fuel causing it to bog...
Car is loading up on fuel causing it to bog and loose rpm like crazy when you punch the throttle. Once it does this then it takes a second or two for the engine to recover and the rpms to come up again. It also does this when you punch the car in neutral. Anyone know what causes this? The car did it without the blower belt connected to the blower also, so it's not even fuel injection related.
Combo is:
383
vortech s trim
speed density
crane hi 6 box and msd coil
plugs gapped at .34"- they're new
wires are 17k old
38 lb injectors
The car only does this from a punch of the throttle. It doesn't ping like some blower cars when they go lean from the fmu kicking in, in transition from vaccuum to boost. It seems super rich. It's very similar to me kicking on my alky system with the car idling; it floods the motor.
Can this be cleaned up with simply a chip? If so, who should I contact. Car is obd 1 and I'm in CA, so it would have to be a mail order chip probably.
Any input is definately appreciated.
Combo is:
383
vortech s trim
speed density
crane hi 6 box and msd coil
plugs gapped at .34"- they're new
wires are 17k old
38 lb injectors
The car only does this from a punch of the throttle. It doesn't ping like some blower cars when they go lean from the fmu kicking in, in transition from vaccuum to boost. It seems super rich. It's very similar to me kicking on my alky system with the car idling; it floods the motor.
Can this be cleaned up with simply a chip? If so, who should I contact. Car is obd 1 and I'm in CA, so it would have to be a mail order chip probably.
Any input is definately appreciated.
Team Owner
Joined: Aug 2000
Posts: 24,125
Likes: 3
St. Jude Donor '14
Sounds like you've got too much fuel at idle. Rather than just getting a mail order chip. Go to your local dyno shop with a WB02 and get a reading of how rich or lean it is throughout the rpms. Then you have something to go by. You can try backing off a bit on the fuel pressure till you get it tuned, this will help with the rich condition at idle. Just don't drive it hard till it's properly tuned. You don't want to be lean during a hard pass.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
there's obviously a chip in it right now, but I'm not sure of the specs as I'm not the original owner of the car. The car doesn't run visibly rich at idle which stumps me. It even passed California emmisions testing without doctoring the car to run lean or cleaner.
What I'm trying to determine if this is a hardware issue with parts on my car like the fmu, map sensor, ect or if it's a software issue with the chip programming.
The car runs fine other than the throttle response is jacked.
What I'm trying to determine if this is a hardware issue with parts on my car like the fmu, map sensor, ect or if it's a software issue with the chip programming.
The car runs fine other than the throttle response is jacked.
Team Owner
Joined: Aug 2000
Posts: 24,125
Likes: 3
St. Jude Donor '14
Have you driven it with the FMU disconnected ( no wot of course ) and see if your problem clears up ? Other than that, you'll need to hook a fuel pressure gauge to it and monitor the pressure as you drive. I use 200 mph tape (duct tape) to tape the gauge to the windshield. Also, if you have access to a scanner, have it scaned. Take a peek at the 02 sensor while your at it.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
that's a great idea. I do have a fuel pressure guage in the car, but I have to hook up the electrical wiring, so it's not working yet.
BTW, the fmu should only be seeing boost, not vaccuum right?
BTW, the fmu should only be seeing boost, not vaccuum right?
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Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by qwiketz
that's a great idea. I do have a fuel pressure guage in the car, but I have to hook up the electrical wiring, so it's not working yet.
BTW, the fmu should only be seeing boost, not vaccuum right?
BTW, the fmu should only be seeing boost, not vaccuum right?
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
turned out to be the coolant temp sensor. The wierd thing is before upon startup with the sensor connected it ran like garbage for about 30 seconds. With the sensor disconnected it ran good cold but ran increasingly rich once it got hot.
Now that I installed a new sensor, it is back to running rough when cold and stalling when I change from park to gear.
Now that I installed a new sensor, it is back to running rough when cold and stalling when I change from park to gear.
