Help 95 runs terrible
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Joined: Feb 2007
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From: North Carolina
Help 95 runs terrible
The 95 LT1 has 148,000 worry free miles. It has developed a miss or skip. I have changed the fuel filter and plugs with little or no change. The old plugs looked good. I don't know if it is spark or fuel related. It has bad hesitation and sometimes it bogs so bad pulling off it feels like it will stall. If it was the 64, I'd know where to start. But I am going to have to educate myself on the newer technology. Anybody have any ideas on where to go from here?
Le Mans Master
Joined: Jan 2006
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From: Orlando FL
I would get a gauge a check fuel pressure. Normal readings are between 35 to 42 psi. for normal engine operation. You might need to hang the gauge outside the hood while you drive and monitor it. The valve is on the top rear of engine on the fuel line. Remove the right plastic cover for to get in easier. If you don’t get this pressure, possibilities are FPR, pump or clogged sock on pump in tank.
The other possibilities are a bad opti causing bad spark. They cause a lot of problems and can’t really be checked for an absolute determination if defective. Substitution only real way.
Of course there is a pile of sensors and engine monitoring devices that feed back to the PCM that can be checked. But most common problems are the basic ones with fuel pressure problems or spark (opti). Don’t let the complexity get you down. Think basics at first before you go off in a tangent.
If you want to work and learn about the car, get the FSM (factory service manuals) from Helms.
The other possibilities are a bad opti causing bad spark. They cause a lot of problems and can’t really be checked for an absolute determination if defective. Substitution only real way.
Of course there is a pile of sensors and engine monitoring devices that feed back to the PCM that can be checked. But most common problems are the basic ones with fuel pressure problems or spark (opti). Don’t let the complexity get you down. Think basics at first before you go off in a tangent.
If you want to work and learn about the car, get the FSM (factory service manuals) from Helms.
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Joined: Feb 2007
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From: North Carolina
No codes in system. I have measured the resistance of each injector and they all read around 14 ohms. I have also noticed that it doesn't run too bad until it reaches operating temp. Then, like flipping a switch it begins to skip and sputter. I should have bought the manuals before I had trouble, but I need to go to work monday. Its too hot to drive the old 68 P/U but maybe I'm just spoiled. P.S. thanks for the replies. Dennis
Le Mans Master
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From: Orlando FL
I think if it runs good when cold, you can almost eliminate a fuel problem. (I’m not saying don’t check it). But one of the classic symptoms of a bad opti is when it get hot it runs bad. Bucks, sputters misses, kicks under load in high gear, but runs better in lower gear and may have a wandering idle at times. If you have some of these problems if may be an opti.
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From: VA
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Joined: Feb 2007
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From: North Carolina
HAHA! Thanks to all for the help, I am going to get an opti cap rotor and some wires and try that. I just hate to act like the local dealer and change parts until I hit the problem.
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Le Mans Master
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From: Orlando FL
You will probably spend both days of the weekend to get it done the first time. And you can get lots of help her plus do’s and don’ts.
But the first word of advise I can offer is replace the entire opti. The cap and rotor are not cheep either. The work is the same and is would be advisable to change out the entire unit. It is 13 years old. The bearings do wear, and cause wobble, the low voltage section and corrosion on the disk can cause problems also.
But the first word of advise I can offer is replace the entire opti. The cap and rotor are not cheep either. The work is the same and is would be advisable to change out the entire unit. It is 13 years old. The bearings do wear, and cause wobble, the low voltage section and corrosion on the disk can cause problems also.
Last edited by pcolt94; Jun 9, 2008 at 06:12 AM.
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From: North Carolina
Well, just an update. A friend recommended taking it to the local dealer and let them identify the problem. They could scan the system and then I could let them fix it or just pay the diagnostic charge and fix it myself. Monday morn. I took it in. They called about 3 hours later and said it was the EGR valve. I was skeptical but I told them to fix it. After all, I would have to pay the diagnostic fee if I did not let them fix it. Long story short, $275.00 later, it didn't get 2 miles down the road before it started skipping again. I had to get home so I didn't turn around but I called the service writer when I got home. You can imagine what the conversation was like. In their defense, they said they would find the problem and credit me for the $275.00. We'll see how it goes.
Safety Car
Joined: Apr 2003
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From: VA
Ouch. I think you'll come out cheaper eating the $275 and fixing it yourself.
There have been many many horror stories about Chevy dealers diagnosing these cars. They don't know the first thing about any car more than 10 years old.
If they end up replacing the opti, you're looking at $1000-1500 depending on location, and that's without doing the things a DIY would do at the same time - WP, seals, wires, etc. Could easily be $2000 for them to do the basic maintenance that is needed before you can even start to diagnose the problem...
There have been many many horror stories about Chevy dealers diagnosing these cars. They don't know the first thing about any car more than 10 years old.
If they end up replacing the opti, you're looking at $1000-1500 depending on location, and that's without doing the things a DIY would do at the same time - WP, seals, wires, etc. Could easily be $2000 for them to do the basic maintenance that is needed before you can even start to diagnose the problem...