I bought my 91 rs a couple of months ago. It ran pretty good and then one day it started backfiring and jerking pretty bad. It was pretty wierd. I put a tune up (plugs, plug wires, dis cap, rotor button, and fuel filter, oil change) and the check engine light was on. It told me to change the manifold air temp sensor so I did. It did not fix the problem. It does not always run bad, sometimes it runs great but mostly bad and also slow to crank when fired. It has a 350 tbi, with a 6 speed and msd ignition, msd distributor, and msd 6 box but the retard advance is not being used. Any ideas? Not sure what to do!

 

get on msd s website, there should be a phone # to call or a help page or button. ask them what it could be in the ignition. sounds like a timing issue.

 

Would the timing go outta whack like that? It ran fine and then just started acting up. the distributor was never turned to modify the timing. Just wondering if this is a normal problem. Not saying you are wrong, just wondering. thank you!!

 

i was thinking something in the msd system may be throwing your timeing off. i was thinking it could be the timing chain jumped a tooth but that would effect it all the time. now a sticky valve might be something that could do that. do compression test. maybe put a timeing light on it and see what it says when its running good and bad.

 

I restore camaros and corvettes. I have a teal green 92 camaro rs. I have completely remodified it to where nothing is stock. Besides the point. I have a 92 teal green corvette with a lt1 350 in it as well. I have had it for years. Ran like a dream. I maintained it as always, washed it, garaged it. Well, one day I took it to the local carwash and did my usual routine. I left and got about a mile down the road and it started to back fire and act up. Note: I did not wash the motor and have not for a while. I got it home and let it sit for a day or two. Hoping that whatever might have fouled up or possibly got wet, dryed. The problem persisted and starting it was a nightmare, keeping idle was impossible, ran rich and backfired everytime I revved it. I went through everything. I changed out the plugs, wires, oil, gastank and gas, fuel filter, vapor canister, egr valve, every possible sensor. Name it. Still the same results. I thought it might have been a head gasket? Compression check was negative. Everything was fine. I took it to a buddy of mine. He went through it. I had spent hundreds of dollars in parts and you know what it was? The opti-spark distributor had gotten a little water in behind its gasket and over time rusted the bands inside the distributor. So, your coil in yours might have the same problem. Take your distributor out and go through it carfully. There inlie your problem might be....good luck.

 

Thank you for your advise, but I finally figured it out this weekend! I pulled the MSD 6 plus box out and it runs great! I guess the box was messed up. Now I just need to send it to msd for repair. Thank you very much!!

 

I finally figured it out. I took the msd 6 plus box out and the car runs great! Thank you for your help and advise. You were right about the msd system!

 

threads merged. please remember that posting the same thread in multiple sections is not allowed. It does not actually increase exposure under most circumstances, and results in fragmented answers.

 

I would never put a MSD system in my car. All I have heard were horror stories once someone messed with the stock system.

 

Well I guess I have learned my lesson!!