Problem with Olds 350. Please help!

[mheath717]

I have a rebuilt Oldsmobile 350 in a 84 cutlass. The casting numbers from the motor say it is a '68-'70 according to 442.com. The motor has a brand new HEI distributor. The engine is not on the computer. It is basically stock except for a little comp cam, and an edelbrock 600 cfm carb. The motor only has about 100 miles on it.

The car runs fairly decent when cold. When the motor warms up, it runs bad and acts like it wants to die at an idle. It will drag really bad when trying to start it. Then eventually it will start up, sometimes. My guess was the timing was off, but i checked and it is set at 20* @ 1100 rpm with the vaccum advance plugged off. Is there any other timing setting that works better? Advance it or Retard it any? Or if not, what could the problem be?

 

[Minion1186]

well advancing the timing to 25 would make you have to run 95 octane to prevent pinging,my 307 likes to idle rough also,but not die.How hot is the cam,maybe it is something with the distributor.

 

[mheath717]

The cam is just slightly hotter than stock. I dont have the card with the specs with me. But I have heard that the cheap chineese distributors are garbage. Thats exactly what I bought off eBay for like $50. It looks like one of them MSD Billet Distributors. But its a cheap one from a guy in California. Could that be my problem?

 

[KrisW]

The distributor certainly could be a problem, but it doesn't make sense for the whole thing to be bad. Your symptoms sound like just a crap chinese module to me.

I would try a used one it and see how it does. Some cheap ones run bad when they get hot like you may be experiencing. I like the MSD or Jeg's HEI module as a replacement, personally.

 

[mheath717]

I've got a brand new Accel 4 prong module at my house. Ill change it when I get back. Hopefully that will work.

 

[mheath717]

I replaced the control moduel, and still have the same problem. I just drove the car about 80 miles on the interstate and the car ran well... but it still has the problem of not wanting to start when hot... The starter really drags... Any other suggestions? Could the starter be bad?

 

[peteyb]

What alternator are you using? If you're using an alternator that matches the vintage of the motor, then it is not designed to run HEI which pulls a significantly larger amount of juice than the points type distributor. I had this exact issue in an Olds 350 I built. I replaced the alternator with the one off of the 307 I pulled and the problem went away.

Another thing to look for is whether the wiring from the alternator is correctly hooked up. Either way, I'm betting you have a charging problem and not a 'distributor' problem.

 

[dan2286]

I replaced the control moduel, and still have the same problem. I just drove the car about 80 miles on the interstate and the car ran well... but it still has the problem of not wanting to start when hot... The starter really drags... Any other suggestions? Could the starter be bad?

So, the other problems went away besides the starter dragging? Are you running headers? If so, it may be starter heat soak.

 

[82cutty]

e only time I have an issue starting any of my Olds engine whether a 307, 350 or 455 if the timing is up and the starter is hot it will hard start. Also depends if you have a regular or hi torque starter. I would try 2 things here..... New distributer and time it and drive it with out hte vacumm advance hooked up. If it runs better back down the timing a bit. If it still dies it it you may have the distributer off a tooth or crappy starter. I run an alternator on my 425 that was for the 425 back in 1965, I have HEI and MSD and have no issues.......

 

[breeaad]

My first car was an 83 GP 305 Chevy. The engine had been overheated pretty bad before I got it. It would hard start when hot just like yours is doing. I tried a few different starters but that didn't help. Retarding the ignition timing would help, but would still crank slow. It was also not a charging issue, as putting jumper cables or a charger on it would not help. I always blamed it on that engine being overheated had tightened the engine up enough to cause problems. Your engine may have been overheated in the past, and as we all know Olds engines don't like to be overheated.