Hey yall,

I have an 86 2.8l MPFI Camaro that won't start and I'm really stumped on this. I'm getting spark at all cylinders, getting fuel, engine is cranking, but no start. I'm fairly certain I have compression and nothing has been done to the timing since it last started a few days ago. Voltage is reading 12.4 in accessory and around 10.4 while cranking. Let me know if some of yall could help me out here.

 

Any codes? I can grab some diagnosis pages out of the 88’ Firebird service manual if you want the “official” diagnosis procedure. Some stuff wouldn’t apply to your 86 but the engine stuff would be identical.

 

An engine requires spark, fuel, compression, and air---all on time---in order to run. You have one or more missing.

Shoot some brake cleaner into the air intake and then try to start it. If it fires momentarily, you have a fuel issue; if not, you likely have an ignition problem.

 

"Getting fuel", meaning, it has fuel pressure? Or?

 

Have you checked timing? Are you certain youre getting spark when need or just intermittent spark? My 1st 87 Firebird with the 2.8 had an issue with the pickup coil in the distributor. It began as an intermittent issue then one day stopped running altogether.

 

Fuel is getting into the cylinders and when I pull the spark plugs, after cranking on it for a bit, I can smell the gas strong.

 

I haven't touched anything with the timing at all but I suppose it could be that, but if so that may be out of my range of expertise. And I am certain all cylinders are getting spark, though maybe not at the correct times, but I can hear the car backfiring a bit when holding the gas while starting it.

 

I'll get back to you on that, I haven't checked any codes as I didn't think it would help me here.

 

That sounds like timing off.

 

If you haven't touched the timing (as in loosened the hold down bolt & moved the distributor) the only way the timing would move would be if the timing chain has jumped a tooth. Without moving the distributor, you need to find out if this is so. You need to put the engine at a few degrees before TDC of the compression stroke of the #1 cylinder, and then verify whether the distributor's rotor is actually pointing at the #1 cylinder's wire.

Edited to add this clarification,

This statement;

"If you haven't touched the timing (as in loosened the hold down bolt & moved the distributor)"

means; "IF YOU OR NO ONE ELSE HAS RECENTLY LOOSENED THE HOLD DOWN BOLT & MOVED THE DISTRIBUTOR"

And the bolt is properly tight as it's presumed to be, , , , ,

The timing doesn't just change on it's own.......

 

Or the dist was left too loose after the last timing adjustment, and it spun the housing.

Was timing adjusted previously to this:

 

This could be an indication that you're getting too much fuel. Check the fuel pressure regulator vacuum hose to see if it smells like fuel. You can further diagnose fuel issues with a fuel pressure gauge to see if it's holding pressure after key on engine off after the 2 second prime. You can try a WOT start to see if that improves the "attempts" to start. IIRC these engines also have a cold start injector that could be leaking. An erroneous coolant temp sensor that tells the ECM that it's colder than the actual ambient temp can provide too much starting fuel as well.

 

Thanks for the responses yall. Been busy the past few days due to the Holidays and what not. I should have clarified that the distributor was replaced about a year ago by the previous owner.

 

had a similar problem with 86 2.8.. was getting spark but it was intermittent weak spark which i didnt realize at first, tried everything to fix the intermittent no start.. turrns out once i replaced the ignition coil all my problems were fixed. that's when i realized even though i was getting spark.. it wasn't strong enough.

 

I thought of that when I was going through the whole mess and replaced the ignition coil. Found out after that was that the distributor was 180 degrees out of sync from when the previous owner had replaced the distributor. Was a headache for me to figure out with my little experience. Runs right as rain now