The problem is, my cars runs like's only 3 cylinders are firing, and I can barely rev the engine above 2500 rpms. I check the plugs, only to fund that they were wet with gasoline and horribly carbon fouled. The strange that sets my problem apart from all the other threads with similar problems, is that the factory boost gauge show 7 psi at idle. When I rev the engine, it quickly rises to over 15 psi. My aftermarket gauge reads around 10 psi vacuum at idle, and 0 when I rev the engine(pretty much normal). It looks to me the engine thinks that there is boost, and responds by increasing fuel, which is pretty much tanking the engine. I don't know what the factory boost gauge is based on, so I can't really figure this out. I've played with the timing a but, which only smoothes the engine VERY slightly, and I've changed the plugs (which foul in like 30 secs, literally). I think the key here is the whole boost thing. Please give me some info, so I can get back to driving my fun car. Thanks
Engine barely runs-can't find anyone with similar problem
WanneBe
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The problem is, my cars runs like's only 3 cylinders are firing, and I can barely rev the engine above 2500 rpms. I check the plugs, only to fund that they were wet with gasoline and horribly carbon fouled. The strange that sets my problem apart from all the other threads with similar problems, is that the factory boost gauge show 7 psi at idle. When I rev the engine, it quickly rises to over 15 psi. My aftermarket gauge reads around 10 psi vacuum at idle, and 0 when I rev the engine(pretty much normal). It looks to me the engine thinks that there is boost, and responds by increasing fuel, which is pretty much tanking the engine. I don't know what the factory boost gauge is based on, so I can't really figure this out. I've played with the timing a but, which only smoothes the engine VERY slightly, and I've changed the plugs (which foul in like 30 secs, literally). I think the key here is the whole boost thing. Please give me some info, so I can get back to driving my fun car. Thanks
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88 Posts
1) Re-gap the plugs
2) Throw in some fuel injector cleaner
3) Set the timing VERY precisely...
ground the ignition timing terminal (make sure you have the jumper wire on the right prong in the terminal -- the metal one) with the car off...then turn it on...turn the screw in the throttle body so the idle so it's at exactly 800 rpm -- timing changes based on RPM...so you need to be sure your timing is set @ -5 while @ 800-900 RPM... and then once that's set turn the CAM sensor so that the timing mark is EXACTLY on -5...turn car off...tighten cam sensor down...remove jumper wire...and start back up and see how it runs...
Honestly the timing doesn't allow much room for error...cars that are timed even slightly retarded can run VERY RETARDED. I had timing set @ -3 and it affected the car unbelievably. On the other hand too advanced timing has it's own problems. Anyway give us an update when you're sure everything is in spec. (Follow my steps)
2) Throw in some fuel injector cleaner
3) Set the timing VERY precisely...
ground the ignition timing terminal (make sure you have the jumper wire on the right prong in the terminal -- the metal one) with the car off...then turn it on...turn the screw in the throttle body so the idle so it's at exactly 800 rpm -- timing changes based on RPM...so you need to be sure your timing is set @ -5 while @ 800-900 RPM... and then once that's set turn the CAM sensor so that the timing mark is EXACTLY on -5...turn car off...tighten cam sensor down...remove jumper wire...and start back up and see how it runs...
Honestly the timing doesn't allow much room for error...cars that are timed even slightly retarded can run VERY RETARDED. I had timing set @ -3 and it affected the car unbelievably. On the other hand too advanced timing has it's own problems. Anyway give us an update when you're sure everything is in spec. (Follow my steps)
No offense to the above poster, but don't do any of that shit.
10 inHg at idle isn't good at all. You either have a huge vacuum leak, or your valve timing is off. The first thing you should do is make sure that the timing marks on the belt line up perfectly. Refer to the VFAQ on information on changing your timing belt.
If the timing belt is ok, then build a leak tester and pressure test your intake tract. You'll find information here and there about building one. I don't know any links offhand, but I'm sure you can search for them. Fix any leaks you find.
If those two things don't fix your problem, post again and we'll try to help you out.
10 inHg at idle isn't good at all. You either have a huge vacuum leak, or your valve timing is off. The first thing you should do is make sure that the timing marks on the belt line up perfectly. Refer to the VFAQ on information on changing your timing belt.
If the timing belt is ok, then build a leak tester and pressure test your intake tract. You'll find information here and there about building one. I don't know any links offhand, but I'm sure you can search for them. Fix any leaks you find.
If those two things don't fix your problem, post again and we'll try to help you out.
The ECU reads the amount of air passing through the MAS. It also knows engine rpm and thereby calculates boost. The after market gauge reads actual boost. The difference between the two readings indicates how big of air leak you have.WanneBe said:
The ECU thinks all the air passing through the MAS is getting to the engine and is supplying enough fuel for that amount of air. Hence, you are running very rich.
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153 Posts
sounds like a vacuum leak... if an intercooler pipe becomes disconected on my car this is almost exactly what mine does.. check all of your intercooler pipes... and also check all of your vacuum lines.. especially the ones going to and from the bcs...
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88 Posts
Michael said:
Damn guys, thanks for all the replies. My timing is right on so it definitely wasn't that. Low and behold, I noticed one hell of a leak from between the engine and the exhaust manifold. Of course, when I went to tighten the stud, it practically FELL right off. I'm serious, I put like zero pressure on the nut and the stud came right off. Anyways, does a leak at the exhaust manifold sound like it would cause the problem? Thanks for the help guys!
Alright, I can't hear/see any leaks. The only thing I can hear is the air going through my K/N, and air going through the throttle body and elbow. All the hoses look secure and they're all in good condition. The car has been sitting a while waiting for the new tranny. You don't think it's possible the last time I put gas in (in Sept) I happen to get bad gas and since then water has condensated in the tank. This is the only thing I can think. I'm going to try to siphon the tank and put some new gas in. Any thoughts. Thanks for the help so far guys.
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330 Posts
You DID make a intake leak tester didnt u? I dont think you did because in your last post it says u can hear air going through your K&N and if u have a leak tester u take the whole inlet pipe off. It is almost Impossible to hear a leak w/ the car running... What u need to do is build a leak tester.. should cost no more than 10 dollars.... check out the VFAQ's and it will tell u everything u need and pictures. Its soo worth it. and when u do the leak test hold the throttle plate open also... If you hear a leak but still cant find it.... put soapy water on all of your hose connections and look for air coming out.
Other wise.... u really wont beable to find a leak.
-Dan-
Other wise.... u really wont beable to find a leak.
-Dan-
No, no, no, no, no, no, no, no, no . . . well, ok - if you're really bored.
I'll say it again and this is the last time. 10 inHg at idle isn't good! It's bad! Mean big problem! Something not right! Air not get in engine properly!
You either have a big-ass vacuum leak, or your valve timing is WRONG.
You said you checked the timing, but I don't believe you. Did you remove the upper timing belt cover, the driver's side motor mount, the power steering belt, the alternator belt, the AC belt, the water pump pulley, the crank pulley, the lower timing belt cover and make DAMN SURE that the timing marks are properly lined up and the tension on your timing belt is within spec? If you did, then my apologies. If you haven't done that yet, then do it before you run the car any more.
IF your valve timing is right on, then build a leak tester and find the vacuum leak. You'll need 3 things for a cheap leak tester, and 4 for a slightly better leak tester.
PVC end cap.
Valve stem.
Air compressor or a bicycle pump.
Large radiator hose (optional).
Drill a hole in the PVC end cap - insert the valve stem into it. Detach lower intercooler pipe from the turbo and insert the PVC end cap with the valve stem pointing out. Clamp it down. Block the throttle open. Pressurize it with the air compressor or the bicycle pump. You will hear air hissing out wherever the leak is. Then fix that leak and repeat until there is no more hissing.
If you use the large radiator hose, then insert the end cap into one end of the hose, and slip the other end of the hose onto the air inlet of your turbo. Continue as instructed above.
That's how you fix it.
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268 Posts
One thought - I agree the timing should be checked, but a compression test will tell the tale right away...
Alright, I checked for leaks, found one at the UIC->intercooler, and one at the throttle body. My throttle body gasket had practically disintergrated. I fixed both, started the car, same problem. Let it idle for a few minutes as I double checked I tightened everything. Still 10 in/Hg, rev the engine a little (2500) and magically, it started to idle like it was supposed to. Vacuum went to 20 in/Hg, the factory boost controller stopped reading boost, and things were looking good. I gave the car some gas, but it won't go above 4000. It hits 4200 then starts sputtering and backs down to around 3000. I don't get this at all. I'm going to recheck the timing this weekend, and recheck for leaks, but I'm still confused. Thanks for helping me through my ignorance guys.
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72 Posts
Since you seemed to have fixed some things and it showed some good signs, you should probably pull the negative lead off the battery for a minute or so to 'reset' the ECU. You know that it remembers stuff, and sometimes it's best to make it forget!
ok sounds like a problem i have, it seam to be ok till you give it some gas. Well wires and plugs are cheep and maybe need to be replaced anyways, ecu that is bad can do it, i just found out that my mass is bad and my knock sensor is out to. i made one of those code cheker for this web sit to find out what was wrong.
http://207.154.72.181/archives/m/1998/09/19980907.txt/23.html
But also it could be a long list of other things. Could you give me a more info on how it performs?
dose it run fine when first started up??
is it always at 4000-3000 rpms?
can you take it out or gear and it still wont pass 3000-4000 rpms?
http://207.154.72.181/archives/m/1998/09/19980907.txt/23.html
But also it could be a long list of other things. Could you give me a more info on how it performs?
dose it run fine when first started up??
is it always at 4000-3000 rpms?
can you take it out or gear and it still wont pass 3000-4000 rpms?
The car still starts just like before, and stays like that for a few minutes. I changed when I blipped the throttle. All this is at idle. If I try to drive it around, it starts to crap out on me like before. Under load, I can't go over more than 2500 RPM. My wires are pretty new Accels, so I really doubt they are bad.
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72 Posts
Maybe you could be having a fuel problem. Have you ever changed your fuel filter?
Why can't you get it above 2500? What happens exactly when you approach 2500?
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