new member with problems

with the car, i mean. It's a 95 supercharged, high mileage (160k but in extremely good shape though with all maintenance always done), just bought it last week. It sat for over a year, and since it's been back on the road (supposedly) it has a problem: idling in park, it runs a little rough and at about 1100 RPM. Also, when you get it out on the road and it shifts into overdrive it stumbles all over itself... feels like the engine is starving or something. Also, the exhaust stinks really bad, like sulphur or something.

My first thought was that it needed a tune-up. I replaced the plugs, wires, and fuel filter; but nothing changed. Didn't have access to a fuel pressure guage, but it seemed adequate when I removed the fuel filter. Then I did a fuel injection cleaning. At first that seemed to help, but within just a few miles it was back to the way it was. Then, I started looking for vacuum leaks. I heard what I thought was one, but determined the sound was coming from the EGR valve. My dad happened to have a new one and I replaced that, but the problem persisted. I started spraying some electrical parts cleaner around the engine bay, looking for vac leaks again. I found that the pipes going in and out of the EGR were leaking where they went in and out, so I teflon taped those and the hissing sound went away. Also, it didn't bog the engine down when i sprayed that stuff at it. Still, though, it wouldn't idle smoothly and stumbled in overdrive. I put in a vacuum/boost guage, and found the vacuum to be about 15 at an idle and I could pull around 5-7 or so for boost on a brisk take-off. Anyone know the normal parameters for this? Running out of ideas, I punched out the cat converter thinking it was clogged or something, but still no change. Please help me before I wind up in a mental health facility.

Welcome. 5-7 PSI boost is about right. Have you cleaned the MAF sensor? Easy to do, and could help things. There is a possibility this could be transmission related due to your symptoms in OD. The exhaust stink is normal after you gut the cat. Don't breath it - bad for the lungs!

You had a smell before punching the cat ?.. Have you checked or changed the O2?

yes, the smell was before I punched the cat... I don't really smell anything now, I think that may have been leaking from the EGR??? Haven't checked the O2 yet, good advice. I'm having the code reader put on it today, so I'll see what that says.

If the problem occurs immediately when you start the car, I'd say it's not the O2 sensor. Since you're in open-loop mode until the car warms up, the O2 sensor isn't used, and so likely isn't causing the problem. If this is something that happens only when the car is warmed up, then the possibility is there.

another observation... maybe someone has some ideas. In a low RPM cruise when it begins to stumble, the vac/boost guage will come up to 0 (no boost or vac), or even go up to 5psi when it gets real bad. Ideas???

What happens during a 0-60 mph WOT run? Any vibration under hard acceleration? How new are the ignition wires?

in higher RPMs it runs great. She just got some new wires last week...

another update on this, I just wonder if anyone has any ideas. The code reader said something like, "EGR pintle circuit error" and it also threw a multiple cylinder misfire code. Replaced EGR, but no change. I started to notice that when I came to a stop all the lights would dim. I removed the alternator and spun it and noticed it was making a grinding sound. Replaced that. Lights didn't dim any more but drivetrain symptoms persist.

Just yesterday, things started to get really wierd. I stopped at a light and suddenly the idle changed. I don't mean the RPMs dropped, but it kind of just smoothed out a little. When I took off, I heard a kind of whining sound which I think was the blower. I wasn't hearing that before. It seemed to run better for a minute, so I got on it a bit and I heard what I think was a backfire or something... besides that and overall, though, it was running better. No choppy idle or stumbling at a low RPM cruise. Unfortunetely that didn't last long.

Now, when I start it, I notice the supercharger belt tensioner slaps back and forth. The tension on the belt seems good and the tensioner is okay I think. Could my problems have to do with the supercharger coupling do you think?

p.s. the car is for sale on ebay, hahaha. If anybody wants to look at her just type in "1995 riveria".. It's the one located in Maine.

hey guys, remember me??? My '95 had been sitting in the driveway for over a month now because I can't stand to look at it or even talk about it. I'd like to fix it but am completely out of ideas, so I figured that I'd ask you people one last time before I send her to the crusher.

If you recall, the symptoms are a rough idle and severe stumbling in overdrive and under a load, and this has progressed to beginning to "break down" when extra throttle is applied. I have: replaced plugs, wires, fuel filter, alternator, EGR valve, and done a fuel injection cleaning. I also tested the coil packs and the fuel pressure (which runs at about 35psi no mattter what RPM... is that normal?) Some have said that the stumbling in O.D. is the transmission, but I don't think it is because when I serviced it there was no band dust or metal filings in the pan.

I hope someone has some ideas because I'm fresh out. I tried to sell the car on EBAY as a "mechanic's special" but the bidder was dead-beat, as they say.

P.S. 1200 bucks and it's yours!

mines doing the stutter in overdrive but i dont have any of the other problems i also have no idea what it is

I also have a VERY slight stumble in OD, my Boost/vaccum gauge shows that it only when my vaccum is around 15-18, and the needle quivers with the stumble. RPM ramains unchanged. My transmission pan was also really clean with new filter. and has had mostly the same things replaced as you(zombiesarebad). Only other thing im thinking is some electrical thing. A month ago it had much issue starting. I'd turn the key, it would start, and cough, sputter, and chug for awhile. Other times i would turn the key and everything would go dead. no dash lights nothing. everything toast. I check the alternator and BATT, no trouble. After playing with the grounding straps a bit, it has gone away, with this slight OD stutter left behind. Dunno if it helps...

hey mine did similar with elec starting issues it would start sometimes no prollem then sometimes it would just buzzer at me and id have to wait like 10 minutes to try again and it eaither start or do it again

sounds like you might have a bearing going bad somewhere along the serpentine belt trail maybe even on your supercharger.

hey zombiesarebad, i was thinking last night, your reported 15 of vaccum on your boost/vaccum gauge seems like you may have a large vaccum leak still. Mine sits with the needle buried past 30 at an idle. And I know from seafoaming in the large vaccum line for the break that the engine runs like a bag of hammers with even a slight leak.

hey thanks for the input. I'll check for leaks on it again- maybe there's a crack or bad gasket on the intake manifold or something. I'm glad you caught that.

It sounds to me like a cracked spark plug or bad wire. I know you said you just did plus and wires, can you re-check the plugs? I cracked the ceramic on one of my rear plugs once while installing it and had symptoms like you describe.

still haven't had a chance to look over it yet (I work like a slave). I'll check for a cracked plug, but it was doing that before I ever changed them.

nor really related to your stumbling problem, but are you still getting an EGR error ? I did not see that you did the reset procedure after replacing the egr. I'm not 100% sure if it is necessary on the obd1 cars.

I don't think it is, but somebody correct me please if I'm wrong.

somehow I forgot to mention an important development in my ongoing struggle with this infernal machine. The last couple times I drove it, this horrible banging sound would come from under the hood when accelerate or apply even light throttle. It would happen only briefly, but while it was happening it was obvious no power was going to the wheels. I think maybe it was just misfiring like crazy. Ideas anybody???