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A friend has a 1985 Cadillac cimerron with a 2.8 v6 and only 80k miles. Not even rusty!
We recently did a tune-up which was made easier by removing the upper intake. There is a block that has hard fuel lines screwed in, and that block was cracked. We replaced that block with a salvage yard part and added new gaskets all over. He even has an fsm, but it’s not an easy read. It didn’t even have the firing order listed. I did verify and triple checked the firing order, and it’s spot on. New plugs and wires were installed one at a time also. We’ve check spark on all six plugs, definitely has spark. We can smell a bit of gas from the intake also. We replaced nearly every vacuum line carefully. It ran fine before this, but since the valve covers were leaking quite a bit, we did a precautionary tune up too. Rotor and distributor cap looked nearly new, so those remained. It cranks, but you have to mash the gas down to get it to catch, then it backfires and dies.
Please help! No codes will read either.
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This is a variation of the common cavalier and sunbird. Believe it’s also an Olds firenza. Iirc the 2.8 v6 was a pretty common gm motor in many vehicles
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sorry posted didnt post…. I would check if you have a PCV…. sounds like a compression issue… that is what backfireing is caused by… probly not then the engine seals or anything like that….but its probly compression related. or timing related… because of backfireing
compression or air in or exchost, timing… is where the problem would be…. could be flooding
if toyu have a carberator on it… clean it and check it out therially
ya if you have a carboratyor… it hands feul and air ratio… would be very high on my list of suspectsThe car is injected. It has barely 80k miles on it and it ran fine before this. I’ve been back over this a lot and my brain is locking up.
As discussed before, it ran perfectly before changing out the valve cover gaskets and it barely has 80k miles. It never failed to start and it never backfired before. Never.
The “block” that you replaced, Was that the fuel pressure regulator? It sounds like it. Did it start having issues after you replaced that? May want to take a look at that….
The fuel rail is very wide and flat on top, it looks like part of the lower intake, hit its not. The block I spoke of is on the end of the fuel rail nearest the distributor. The fuel pressure regulator is opposite of that. This partnis not available new from any vendor, so he had to go with a salvage part. I checked the flatness of the new part and the fuel rail before assembly, all good.
I was thinking this weekend when I go back, I will see if the distributor is loose, as in did the hold down clamp come loose, allowing it to turn when it got bumped in the process. I also noticed that the coil is a tiny bit loose in its bracket. The wires connecting to the ignition module are also held in via zip ties. I’m going to see if the distributor turns by hand, then play with that until its times right then secure it. I’m also considering looking much closer at the two molex connectors for the ignition module.
I’ve also triple checked the firing order, and it’s spot on with new plugs and wires.
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