Well I recently went through 2 turbos due to my oil feed being clogged up...I now have a spanking new (but still an ebay :P) t3 turbo. The last turbo did this too after I fixed the oil feed line, so I know it's not the turbo itself. I am simply at a loss though...

When I accelerate at WOT, it is slooowwwww. I have a video I'll post up tomorrow probably to show. But it won't boost (should be hitting 7psi) and it has a hard time even getting to 0. The car had difficulty starting a few times and holding an idle, so I tried replacing the throttle position sensor with no success.

I did a compression test today and everything checked out. All 160-180. The wastegate isn't stuck open. I have an open dump, so I'd hear if it was.

Even when I try to rev it up out of gear, it revs to about 5 maybe 6k then just kind of hovers. The throttle is opening all the way, verified that with a buddy.

The car isn't sputtering or anything. It actually runs really smooth...But that's about all I can think of now. If you guys have any ideas I'd reeeealllly appreciate some input. Thanks!

I am going to go with lack of fuel pressure or possibly tune up or clogged exhaust. Plugs will tell you if its leaning out. Is the turbo spinning while you try to rev it up? If the turbo is not spinning or for some reason is locked up then it will restrict the exhaust to the point the motor wont run very well at all especially on the high RPM range.

Terry

Could also be a large boost leak.

Thanks for the replies. I forgot to mention I did about 3 boost leak tests ha ha. There are no leaks what so ever.

I'll definitely try disconnecting my downpipe at the cat and see how it runs then.

Oh I also forgot to mention- I just installed a wideband literally last night. According to that I'm running about 14-15 at idle and probably 12-14 under load.

The turbo doesn't sound like it's spinning as fast as it should. I mean I can barely hear the BOV chirp when I let off a WOT run and I know it should be louder when it spools.

Well the cat isn't the issue :(

What type of fuel system are you running? (pump, injectors, management, etc)

Just a 12:1 Vortech FMU, Walbro 255, and stock injectors.

Could very well be the fact that you are running stock injectors. Are you able to monitor idle and WOT fuel pressure?

How many miles are on those injectors? Have they ever been cleaned or replaced?

Yeah I had the injectors out and cleaned probably less than 2k miles ago. There's a little over 100k on the car/stock injectors.

If I were to guess anything with the fuel system, I'd probably say FMU first personally. But I'll start fuel system troubleshooting now I suppose!

is your fuel pressure rising with boost? you still should feel SOME kind of power when the turbo spools. You said you did a boost leak... try a smoke test on your exhaust. you may have a manifold leak. btw, stock injectors on a 12:1 fmu are fine w/ 7psi

Originally posted by 420agreenvilleSC
is your fuel pressure rising with boost? you still should feel SOME kind of power when the turbo spools. You said you did a boost leak... try a smoke test on your exhaust. you may have a manifold leak. btw, stock injectors on a 12:1 fmu are fine w/ 7psi

I don't have a way to tell right now if my fuel pressure is rising, no guage :(. There is less power than if the car were NA actually ha ha.

No exhaust leaks, I made very sure to seal everything up this time around.


I just remembered today that a few weeks ago when the car was running with a new T3 setup (switched from a small 16g) I was doing a WOT 4th gear pull on the highway and the car just fell flat on its face. It stopped boosting randomly, and when I stepped back on the gas I had no power. After a few seconds of normal driving, it picked back up. What could this be an indicator of?

What kind of FCD are you using??
Also if you have a spare MAP sensor I'd swap that and see what it does.

Originally posted by Nightfall
What kind of FCD are you using??

was my next question.

if you don't have a gauge to monitor if fuel's rising w/ boost w/ an FMU that's designed to do so, that's a big no-no. For all you know, the fuel may not be rising at all and you're running like 18:1 AFR's.

Is this the same FMU that you were running before? when was the last time your car actually SAW power under boosted conditions and how was ITS setup different than what it is now?

I don't need a FCD, it's a 95.

I might swing by auto zone and try out a different MAP sensor.

Originally posted by tec_41
I don't need a FCD, it's a 95. I might swing by auto zone and try out a different MAP sensor.

don't do that. If it's responding well under NA conditions, it's not your MAP.

I replaced the fuel filter for the heck of it, no luck.

Here's a video of a WOT run and a few revs. It's a little blurry, but notice how it doesn't boost, and drops off into vacuum even under WOT -
http://img502.imageshack.us/img502/3873/s8002059.mp4

And here's a strange thing my buddy and I noticed-
http://yfrog.com/hts8002065j

The wires from the cam position sensor look all hacked up. Is that normal, or could it be a potential problem? Notice how the wires are of different color after the crimped area.

EDIT: I found out the wires are different because it's a 97+ CAS...

Check the camshaft timing. kinda wondering if it jumped a tooth. enough to affect performance but not ability to run. lack of top end would indicate too much advance on the cams.

That crossed my mind too. I'll check it and see what's up...


The only reason I think it might not be physical timing is because it had these symptoms 2 times on the highway, then ran perfectly normal for a little while with boost. But ya never know!

I read this about the 95 ECU's...can anyone verify this info? Especially the last part about the injector driver.

"These can also cause issues with erroneous check engine lights, idle control problems as well as emission control & cold or hot start problems. I have also seen fuel pump relay turn on faults (ECU won't turn on the fuel pump), as well as an condition where the high speed injector driver has failed. This causes the car to sit and idle fine, but it won't accelerate."

Also, is the ECU supposed to make a high pitched whine for about 30 seconds after the car's been shut off?

Yes the ECU should make that noise

When you say your A/F is 12-14 under load, do you also mean at WOT? What is your A/F @ WOT specifically?

Originally posted by ez
When you say your A/F is 12-14 under load, do you also mean at WOT? What is your A/F @ WOT specifically?

12 to 12.5 I would say at WOT

That probably means that your fmu is working. Even if it wasn't, your turbo should still boost what the wastegate is set at, the only difference would be lack of power but you should still see boost.