I was driving home from work today, and when i stepped on the gas a little in third gear it basically fell FLAT on its face. It was like the car was hitting a brick wall, it nearly died and was enough to lock up and chirp the tires a little. So i was thinking it was just in need of some heating up. So i let it get up to normal operating temp and i got on it a little at low RPM and it seemed fine. So i downshifted and tried it agian only to have it lock up even harder and stall out this time. The car works fine when driving normally. But it seems like as soon as it hits WOT mode it basically quites working. I am quite baffled, i would really like some help or ideas on this one.

 

When was the last time you did a tune up? Plugs, wires, fuel filter...

 

plugs and wires are pretty new and in good shape.....fuel filter well i have no idea, but i know i have good fuel pressure at idle i have never left the guage hooked up for a run through.

 

I would recommend changing that first, and maybe run some injector cleaner through it.

 

The next thing to think about is the opti did it fall on its face then pick up or did it continue to miss?

 

Yeah take a look at your ign system, make sure your coil wire terminals on wire and coil are clean, check your Grounds by your ign module, and on the pass side of the block.

 

Yup, classic symptom of a burned/bad wire...check all along all the wires/coil in the dark with the engine running and look for a lightning show.

 

It's hard to believe personally that you have a bad wire when you just did a tuneup (plugs, wires, and maybe an opti) unless a wire fell off one of the fasteners and got burned by your headers. Usually if a wire goes bad, it'll make the car miss and hicup just driving normally even. But if your fuel filter hasn't been replaced before, then replace it. If it's really dirty or hasn't been replaced, it's also slowly killing your fuel pump too.

Jason

 

More often than not, it seems that when people have problems like this, the first thing they do is rule out the wires because they recently replaced them...a better troubleshooting method is "what did I recently change" and look there first. Quite often they find it ends up being a burnt or loose wire..unfortunately, it's usually after they change many things, including a perfectly good Opti.

When my #6 plug wire went bad, the car was perfect at light to medium throttle, all the way up to redline. If you tried to quickly accelerate, it would nose-dive and cut-out.

 

Well i appreciate the ideas, i think i found it there is a plug wire #8 that keeps falling a little and hitting the headers. I got it worked up off of it but when i take a hardish right hand turn and give it some gas, it does the same thing.....oh well at least it is good in a straight line for now, i will work on rerouting it this weekend....THANKS guys-carl

 

hey buddy
i had the same problem with my car , a year later after storage it still did it and some time after my fuel pump died, get ur fuel pressure tested also and c how that is

also many ppl have reported VATS(Vehicle Anti- Theft System) to be teh problem , if u have it check that out while ur at it, im not sure but u might be able to dissconnect it and c what happens,

 

A brick wall is what most use to describe fuel cut such as a rev limiter, speed limiter, or over-boost. Replace your fuel filter. Run injector cleaner FIRST so when it breaks crap loose from your tank it doesnt clog up your new fuel filter.

 

Ya i am not sure, i have hit fuel cut before in my old talon TSI, but this almost seems worse. Maybe it is the fact that it is a V8 binding up not a little 4 cylinder. It hasn't been really bad lately but i am kinda afraid of really getting on it. I am gonna try a new fuel filter, and i am planning on a fuel pump install with in the next few months so i may just speed that up a little. Would it be better to run fuel injection cleaner or to just pull the injectors off and clean them one at a time?

 

Run "Guaranteed to Pass Emmissions" through it. That is a very good cleaner. Then replace your fuel filter since that will be clogged with stuff it has cleaned from the tank. With your TSI (my previous cars was TT 3000gt) you have a lower compression ratio so with fuel cut and 4 less cylinders the instantly slowing will seem alot less. I'd hit fuel cut from my speed limiter and believe me it hits hard.

 

OK update...today i got up to go to a training class i was scheduled for (i am in the Airforce). My car wouldn't even start, it turned over fine and everything looked normal, but it just wouldn't fire (not even a cylinder here and there). So i took my g/fs car so i wouldn't be late and when i came home i played with the car a little. I hooked up my fuel pressure gauge and it was reading low 40's with just the key on, and when i was turning it over it was dropping just a little. So i disconnected that and threw my OBDII PCM back in. After turning over a few times it started. So i let it idle for a little and all seemed well. Back in goes the OBDI PCM, and all is well, starts idles and drives. So i parked it and grabbed some lunch and headed for work. I got about a block away and it died agian. So i did a quick roadside swap of the OBDII PCM back in. It ran but died twice more before finally getting me to work. When i left work 6 hours later it once agian wouldn't start. So i played with the PCM's some more and finally disconnected the MSD box just for the heck of it. All the sudden the car started running normal agian. Tomorrow i am going to swap the OBDI PCM back and see what happens. My question is, is it possible for the MSD box to have been fried and making the car run so funny? Also today i noticed that the problem seems to worsen when i am in a turn or when i am stopping. I don't know if that helps anyone but this stuff is really making me angry.