I just picked up a 90 GSX today, and it was running fine. I went to VR then on my way home i started to feel a loss of power, i'd step on the gas and it would stutter and slowly rise in RPM and speed...and by slowly i mean like really slow. So i stopped at autozone and bought new plug wires (which i needed anyway), and new plugs. Installed both and it's running a little bit better but it still stutters and takes SO long to get up there when i step on it. Also at idle the exhaust stutters noticably. Could it be the ECU? still bad plug wires? HELP!!

Good luck man. I have almost exactly the same problem but my car no longer moves at all. Its idling between 600 and 800 rpms and when i step on the gas it sputters out and dies. I'm thinking something is wrong with the mas or the throttle ...maybe sensors...

i just called up a local DSM shop and they said it's probably a vacuum leak or my ECU.

Its probly ur TPS.

Is the TPS hard to replace? what's the work involved?

This sounds like a cam timing problem. Me and a friend of mine changed cams in a probe, and this same thing happened. The car was decent at idle, but when you step on it the car stalls. Maybe it skipped a notch on the timing belt?

Well, i just replaced the fuel filter and test drove it, same thing, so i did a comp. test.

Compression Test Results

Cylinder 1 - 150
Cylinder 2 - 140
Cylinder 3 - 0
Cylinder 4 - 150

All plugs seemed to have no oil, so no signs of blown rings on cylinder 3.

Timing Problem, Correct??

it could be mas, make sure that you have your filter on all the time (very important), i would check cables for mas sensor or sensor by itself

I dont think its the HG, because there is no coolant in the oil and no oil in the coolant, Also car does not blow white smoke. Im thinking the timing belt jumped a couple teeth, hope the valves are still ok and didnt get smashed by the piston, anyone w/ experience w/ this problem?

The CAS should be on your list of things to check

peckgsx05 said:

Well, i just replaced the fuel filter and test drove it, same thing, so i did a comp. test.

Compression Test Results

Cylinder 1 - 150
Cylinder 2 - 140
Cylinder 3 - 0
Cylinder 4 - 150

All plugs seemed to have no oil, so no signs of blown rings on cylinder 3.

Timing Problem, Correct??

Click to expand...

Your intake valves are either stuck or bent. If you had a head gasket problem it would either show 2 cyl. low, Have the coolant smell in exhaust, or be blowing your radiator cap off. Also in 99% of head gasket prob. you will have some compression. If your valves don't shut you won't build any pressure at all. Timing problems will also show on at least 2 cyl, usually all 4 will be out of spec. I just finished some head work at my shop on an avenger with a six. It came in with a timing problem. Someone didn't install the belt right and did not tension the tensioner. They even put the tensioner on backwards so you couldn.t adjust it. Anyway the compression was 160-0-160 on 1,3,5 sent the head off and #3 cyl had 2 intake valves not closing. (Enough babbling) While it most likely is a valve sticking. You could also have a hydraulic lifter problem. You should have a reputable machine shop check it out. Since the head work should be getting done, if you have extra $$$ you might want to beef your ride up. Port and polishthe head. Change all the valves, valve springs, and hyd lifters. Personally I would try to get all of this done @ one time so you don't have to go back in there in the near future. You could also get your cams turned which will save hundreds of $$$ compared to buying a new set of cams. Ill end this babble now. If you have any ?? hit me on pm VJB

"get your cams turned"?? You could pull the valve cover to check the cams and valvetrain operation at idle. Probably a head gasket. Mark

The mas? The cas? Timing problem? Huh? Did you guys not see the post of 0 comp in #3?
Have a mech check it out for verification. VR can obviously do that but I can't see you doing anything else but pullin' the head (unless there was a screw up in the comp tester. For shits and giggles you can try that again).
Sorry,
MB
Oh and I think 95gsth...etc. was possibly refering to a regrind on the cams. They build up the lobes and then regrind them to your specs. I haven't heard much good about this process and I don't think you're saving hundreds (but I could be wrong on that one. Never priced it out).
MB

I spoke to the original owner, and they just recently had the head rebuilt (20k miles ago). After the rebuild, the timing belt snapped and he replaced it. Could he possibly have ####ed up the timing and thus bent a valve? Or would it most likely be stuck?

bump

Why speculate? Pull the valve cover and check the valvetrain action and check for dmage. Then most likely the head will need pulling. Ask the owner what he did with valves/head if anything when he replaced the belt. Did this motor run wel when you checked it out for the purchas?Were you able to drive the car?mark

Right now the car is in the shop. Before I bought the car, I compression tested it and it was 150 on all 4. It was running and boosting fine.

if you have no comp in the cydler the that means it isnt fireing or it is firing but not getting any fuel never thought to check ur injector clips i bet it sounds like a wrx or something like that i had a problem just like that shaking real bad too yea thats what it sounds like but i could be wrong just thought i might help alittle

15poundsoffun said:

if you have no comp in the cydler the that means it isnt fireing or it is firing but not getting any fuel never thought to check ur injector clips i bet it sounds like a wrx or something like that i had a problem just like that shaking real bad too yea thats what it sounds like but i could be wrong just thought i might help alittle

Click to expand...

OK, if you have no comp in the cylinder, that means that you have an air leak in the cylinder. Unless you have a big hole in the side the of the cylinder or the head, then it has to be leaking past the valves or the rings. With 0 comp it is usually the valves. Firing or not firing has nothing to do with it. Think about his; when you do your comp test do you have your spark plugs in (the firing mechanism)? Good luck with the problem. Hope you brought it to a DSM literate shop.
MB

15poundsoffun said:

if you have no comp in the cydler the that means it isnt fireing or it is firing but not getting any fuel never thought to check ur injector clips i bet it sounds like a wrx or something like that i had a problem just like that shaking real bad too yea thats what it sounds like but i could be wrong just thought i might help alittle

Click to expand...

If you don't have any compression, it doesn't mean you are not getting fuel or spark, the compression is leaking past something. You wouldn't be getting any spark because the comp tester is screwed in the spark plug hole
Edit: bullettdsm beat me to it !

if you have no comp in the cydler the that means it isnt fireing or it is firing but not getting any fuel never thought to check ur injector clips i bet it sounds like a wrx or something like that i had a problem just like that shaking real bad too yea thats what it sounds like but i could be wrong just thought i might help alittle

Click to expand...

Periods =

check your injectors. mine went bad and my car studder but didnt die like that though!

peckgsx05, did you find out what was causing the low compression?