Re: `95 Lesabre engine misfire/shaking badly occassionally/randomly

[carolinaguy]

To read original thread, Click Here
Ok, sorry it's been so long. I appreciate all the advice. I tried a few things. They do have a code they were reading, but I'm not sure off hand what it was. I'm not incredibly mechanically inclined, so I'm trying my best to piece everything together from what the mechanics tell me. I do not have a Tac on the dash, so I can't tell what the rpms are doing.

The guys I took it to thought it might be the ignition coils, so they swapped those out. Immediately after turning the AC on, it started missing/shaking again, so i took it right back in. They took the coils off and put mine back on (w/o charging me at all). Then they replaced the Ignition control module. That set me back a good penny, but seemed to fix the problem at first... sure enough a couple weeks later the problem was back. For a couple months it wasn't nearly as bad as it had been, so I thought that the problem was fixed and the car was just being an old car (missing for a couple seconds occassionally on the highway). Now, though, it had been getting worse and espcially with this recent heatwave we're having, it's been HORRIBLE! Shaking and missing very often at high and low speeds, cool and hot.

Also, a new problem developed that I'm wondering if it might be related. It started having trouble starting, where it would turn over a lot but not catch for several tries. Yesterday, for the first time, I tried to start it and it was completely dead... no lights or anything, just a click. Then i tried it 20 mins later and she started perfectly.

I'm really wondering if there's a wiring issue (which unfortunately i don't have the slightest clue how to check myself), or if it could be the PCM as the guys at Hendrick thought last summer. It seems to me that since all these problems are so quirky and random, that either the PCM is bad or there must be a short somewhere... is that a good line of thought with these kind of issues? If the PCM needs replacing, I know they charge an arm and a leg for it... is it possible to change by myself if i pull one from a junk yard? Thanks for your help!

Mike

[maxwedge]

The issue of no start?/no lights is usually caused by bad grounds or battery connections, I'd start there. As for the misfire there is no quick answer, many things can cause this, lean fuel mixture, erratic maf, bad plug or wire, these things must be checked out especially when the miss is present.

[spinne1]

Originally Posted by carolinaguy

To read original thread, Click Here
Ok, sorry it's been so long. I appreciate all the advice. I tried a few things. They do have a code they were reading, but I'm not sure off hand what it was. I'm not incredibly mechanically inclined, so I'm trying my best to piece everything together from what the mechanics tell me. I do not have a Tac on the dash, so I can't tell what the rpms are doing.

The guys I took it to thought it might be the ignition coils, so they swapped those out. Immediately after turning the AC on, it started missing/shaking again, so i took it right back in. They took the coils off and put mine back on (w/o charging me at all). Then they replaced the Ignition control module. That set me back a good penny, but seemed to fix the problem at first... sure enough a couple weeks later the problem was back. For a couple months it wasn't nearly as bad as it had been, so I thought that the problem was fixed and the car was just being an old car (missing for a couple seconds occassionally on the highway). Now, though, it had been getting worse and espcially with this recent heatwave we're having, it's been HORRIBLE! Shaking and missing very often at high and low speeds, cool and hot.

Also, a new problem developed that I'm wondering if it might be related. It started having trouble starting, where it would turn over a lot but not catch for several tries. Yesterday, for the first time, I tried to start it and it was completely dead... no lights or anything, just a click. Then i tried it 20 mins later and she started perfectly.

I'm really wondering if there's a wiring issue (which unfortunately i don't have the slightest clue how to check myself), or if it could be the PCM as the guys at Hendrick thought last summer. It seems to me that since all these problems are so quirky and random, that either the PCM is bad or there must be a short somewhere... is that a good line of thought with these kind of issues? If the PCM needs replacing, I know they charge an arm and a leg for it... is it possible to change by myself if i pull one from a junk yard? Thanks for your help!

Mike

Yes, you can replace the PCM yourself and it's not horribly hard. You have to get the under dash shielding off on the right side (I think the 95's computer is likely in the same spot as a 92 but I don't really know.) Then, you should see a silver box that is rectangular and narrow (maybe 7 inches by 5 inches by 2 inches.) On the 92 you use a 10mm socket to get the bracket off that holds it in place and then you remove the wiring harnesses (or do it in the reverse order of that) and then you shimmy it until it is free. You'll see what I mean when you are holding it. To install do the reverse of what you did to take it out.

[Blue Bowtie]

No special tools necessary. It's cradled in that white bracket: