I'm driving kind of hard. I stop at the 7-11 let her cool down and shut it off. Then come out, start her up, having a very hard time. Then she starts but cant go over 5mph and no boost at all and as boost is about to hit the car stumbles and almost stalls out. I make it home and see that a vacuum line that popped off what i think is the dump valve? I reconnect it and i still have no power and zero boost and she is hard to start and then still stumbles on the point boost would hit. All the vacuum lines seem good, the air side of the turbo spins free. I just cant get boost, the car stumbles and almost stalls at the point boost would start.

All inter cooler hoses are tight and crack free. I changed the air meter and went over the motor with a fine tooth comb. New plugs, cap and rotor. I cant figure this on out. I checked all coeds and everything is spot on. Waste Gate seems fine too. Im searching for a vacuum leak but.. get this i played with the car then when i got up to normal temp it was fine and ran mint with full boost and no issues at all. I let it sit for 45min then the problem was back.

Try to stay positive about it. There is a solution. Logic prevails and anger leads to broken parts or wasted money, right? It does for me anyway heh.

Anyway, you can also try unplugging the AMM when it's hot and see if that improves the performance. It could be failed and keep the engine running rich - which will work decently at lower temps and then make it run like crap when warm.

Also, what about the EGR?

Also, I would pull off each and every intake tube and reattach it. You could also have a crack in your intercooler or be missing the plug (to drain accumulated oil). It's found in the bottom driver's side.

You *might* have an intake hose collapsing once it gets hot, or an airbox thermostat that's failed in the "hot only" position (though my 90 doesn't even have the airbox thermostat, maybe they brought it back for the 900's).

If you think the cat is plugged, running seafoam through the engine should make a difference - either improve it or make it worse. The metal may be rusted and crumbling, but if it's blocked, at least part of the blockage should be soot(carbon) and whatnot.



Most importantly, I'd find out exactly what hose came off and what you reattached it to. Maybe it was supposed to be attached to something besides what you attached it to.

The dump valve (wastegate) usually connects straight off the turbo's output (cold) side with a very short (six inches or less) hose. If that's not working, you'll get too much boost, not too little. The CBV (which feeds the turbo output back into the turbo's intake) needs a vacuum line attached to it.

You can directly monitor the O2 sensor with a simple, cheapo analog multi/volt-meter (about $5-$10) on the 1.0V range. If it stays constantly to one side of .5V, you have a flakey mixture or a dead O2 sensor, though that probably won't cause the problem. If the O2 sensor is working, you'll be able to tell if the mixture is changing like it should - the voltage should sweep between 0.1V and 0.9V and should spend equal amounts of time on each side at idle, at steady non-idle rpm, on increasing rpms, and on decreasing rpms.
If it's a mixture problem, it should be really really obvious like the meter is pegged at 0.9V all the time. I believe that higher voltages indicate rich mixture.

Did you try the OBD1 test mode? I think it's mode 2.

Also, what does the turbo gauge do? Do you have one? If not, can you beg/borrow/steal/buy a vacuum gauge? You might have developed a leak in a metal portion, in the exhaust before the O2 sensor, in an intake or exhaust manifold....

Did anything weird happen just before it started acting up?

Did you check the resistance of the ballast resistors and of the coil? The power stage is always suspect in heat-related issues, but usually fails completely or works fine.

You can clean the ground plate that feeds multiple wires to ground on the fender wall under the hood.

Cheers! and Good Luck!

Perhaps the catalytic converter has collapsed internally blocking the exhaust. Easy diagnosis - start it up and hold a rag over the tailpipe while someone revs the engine in neutral. You'll feel if no or very little exhaust gas is escaping. Worth checking.

Dear librick,

Hope you're well. As this failure seems heat-related - car runs well, once "warmed-up", but runs poorly when cold - I think you should check:
(a) the engine coolant temperature sensor (on the driver's side of the head, towards the back (North American models) and
(b) the ignition power stage. This is mounted on the inner fender wall, just behind the headlight. On a turbo-equipped engine, it may be on the passenger-side fender of the engine bay (normally-aspirated, on driver's side of the engine bay). It has a single electrical connector, is mounted on an aluminum base, and has a pale gray "cap".

The ignition power stage more often fails when hot, but I recall seeing posts, when failure occurred when the engine was cold.

Neither of these is a super-costly item. A failed engine coolant temp sensor usually will set a code (1-2-3).

Hope this helps.

Yours faithfully,

Spook

No luck with anything, im going to just junk this car im so mad..

Played with the car today, same crap. let the car run for 30 min, issues are GONE.. As soon as she is cold, ISSUES ARE BACK.. Madness!

i took some time off and im still going insane with this issue! UGH!!

Hello,


What is the fuel pressure?


Goatman

I never tested it, but i just put a new FPR in. Its madness.. I then though if one of the fuel pumps went that could be it, but then i said.. no why would it run best hot.

Like is say tho, i throw no codes at all, i did everything listed here

http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

And no-dice.

I went crazy assuming it was the controls for the heat and AC, messed around replacing that too.. Nothing conclusive.

I replaced the ignition amplifier, nothing changed.. I replaced the climate control unit nothing changed, when hitting gas and when shutting down i hear a his in the inside of the car coming from the middle right side of the dash.

"no codes at all..."
So, do you get 1 1 1? or, do you get nothing of any kind? If the latter there is something wrong with the process or the OBD.

yes i get 1 1 1

1 1 1 is the code i get

For the most part, with that OBD system, various ignition components can fail without recording a fault code. The OBD is better for tracing down sensors out-of-range, etc.

Several people have reported that unmounting the ignition power stage and cleaning up the interfacing surfaces of the module and the fender cured their problem. A light coating of dielectric grease can help delay future oxidation. I'm nearly certain that neither a failure of the power stage or its grounding with throw a code - nor will a bad spark plug, plug wire, dist cap, rotor, coil....

Im going to try this, i also just replaced the FPR with no luck. Ill keep you guys posted.