Car running like crap...
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Evolving Member
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From: Minneapolis, Minnesota
Car running like crap...
Alright..it's been a while since I have posted but my car is running like $#!t. I though it was my spark plugs, so I ordered new NGKBR7E's. Well, it is still running like crap.
Basically, If I get on it and hit wide open throttle, it bogs down and sounds like the spark plugs are misfiring. If I slowly increase throttle and keep the Air fuel ratio from going totally rich, it will run OK. (Out ran a modded VR6 from a stop the other day doing this...) But, like I said, If I floor it, it seems like nasty fuel cut or misfiring plugs.
So, I'm thinking possibly bad plug wires or a boost leak. Haven't had time to pressure test lately, but last time I had the boost leak it wasn't doing this...
I still have stock plug wires, do you think they have gone bad? Any suggestions would help.. Thanks
Basically, If I get on it and hit wide open throttle, it bogs down and sounds like the spark plugs are misfiring. If I slowly increase throttle and keep the Air fuel ratio from going totally rich, it will run OK. (Out ran a modded VR6 from a stop the other day doing this...) But, like I said, If I floor it, it seems like nasty fuel cut or misfiring plugs.
So, I'm thinking possibly bad plug wires or a boost leak. Haven't had time to pressure test lately, but last time I had the boost leak it wasn't doing this...
I still have stock plug wires, do you think they have gone bad? Any suggestions would help.. Thanks
I had the same kind of probelm $2500 and a month later mylocal shop found it to be a crack in the fuel houseing so i was loseing fuel pressure. The crack came when replacing the fuel pumps. Check that out. But i wen like 4 months checking my MAS spark plugs a new waste gate. And it was the fuel pump housing. let us know
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Originally Posted by NITROHEAD
I had the same kind of probelm $2500 and a month later mylocal shop found it to be a crack in the fuel houseing so i was loseing fuel pressure. The crack came when replacing the fuel pumps. Check that out. But i wen like 4 months checking my MAS spark plugs a new waste gate. And it was the fuel pump housing. let us know
Thread Starter
Evolving Member
iTrader: (8)
Joined: Jun 2002
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From: Minneapolis, Minnesota
alright, update. Pressure tested the system tonight at 13 pounds... Found a nasty leak around the far passenger side injector. We realigned the injector and car held 13 LBS from an air compressor. However, on the way home, I could feel the car was running better but it is still stumbling at WOT... So, either the injector came loose and is leaking agin, or something else is wrong. Anybody know how bad plug wires behave? That's what i am thinking next but not sure...
Well your symptoms sound like they could be a bad plug wire. Stumbling under WOT can definitely happen from a bad wire. I'd pick up a set of Magnacores just to be safe, it's a good investment regardless if the stock ones are bad or not (assuming you don't have Magnacores already). Sucks about the injector, did you grind the rib on the rail down enough for the injector to sit flush? And how does the O-ring look? Just shooting some ideas out to ya. Hope it helps.
mcbrown, i have the same problem every once and awhile. i will be at full boost, but it doesnt accelerate anymore and it chugs somewhat. only happens once every week or so, usually more at the beginning of a car ride.
how about checking for kinks or bends on the return hose of the fmu or the return line back at the fuel pump housing? BOV leaking only under boost?
check wires with an ohm meter. should be less than 19k ohms.
also check your coolant temp sensor. it'll dump more gas if it's lazy and thinks your car is still cold, since you said it's mostly at the beginning of a ride.
check wires with an ohm meter. should be less than 19k ohms.
also check your coolant temp sensor. it'll dump more gas if it's lazy and thinks your car is still cold, since you said it's mostly at the beginning of a ride.
yeah check your vac. lines going to the FMU, i remember you said you had a vac leak somewhere a while ago, if it was there and you replaced the lines with soft lines, the vaccum pressure will actually suck the line inward under high pressure and it will pinch, so when your at WOT the pressure could be great enough to pinch that and decrease your fuel rates.


