hey guys,

here is my problem.

about a week ago my 85 full size blazer shut off on me, but i restarted and it fired up fine, so i did not think much of it at the time. later that week though it shut off again and refused to start again. so I looked over every thing i could think of and still no luck. so i pulled the plugs out and found that they were fouled pretty bad, so i cleaned them as best i could and put them back in, and it fired right up. it run long enough for me to drive about 6 miles, and then it shut off again. so i replaced the plugs with new ones, after that it fired up again and run pefectly smooth for about 30 sec., and then shut off just like you turned the key off. again after that it would not start, it would turn over fine, but it would not even think of firing. however if i waited about a day or so it would do the same thing, fire up and then shut of after about 30 sec., and not start again.

the motor is a stock 350 small block which is carburated, with a acdelco distrebuter.

any help with this would be great. thank you

 

Check your fuel pump pressure.

 

I have not checked that yet, but the carb. is getting fuel, i can see it in the filter that is right before the carb. and if i work the throttle i can see it in the carb. could it be the coil on the HEI Distributor, or the points? I was thinking about replacing those and seeing if that would help.it also has a mechanical fuel pumperthat is onlyabout 8 months old.

 

hey whats going on chief. i have a 88 k5 blazer and had the same problem. What i would do is do a diagnostic test on it to see if there is any sensors that is making the car cut off and if your plugs are looking bad i would also do a tune-up after you see if any trouble codes come up.

 

hey whats up.
my blazer is carbureted and does not have a computer in it so I do not think it has any sensors on it. however I have talked to a few mechanics I know and they think it is the HEI Ignition Module, so I am going to replace it and the condenser and see what happens. I will post another message when I do, and let you all know what happens. I hope this does fix it, I miss driving my truck!!!

 

If you read the owner's manual, it does state there is a computer init. Mine is an 87, it is carbureted and has a computer. It is locatedunder thedash,passenger-side, behind the glove box. Thereis even a section on the computer in the Haynes manual. I can only guess it reads emission-related items (O2 sensor and what-not), since I have not read that section yet.

Keep us updated if the ingnition module was the cause of failure.

 

Pull the coil and ignition module (inside the distributor) and take them down to your favorite parts store and have them checked. I am betting on the ignition module. HEIs dont have points or a condensor.

 

well I replaced the ignition module, and my truck has been run great so for, so that must have been the problem with it. i looked behind my glove box, but I still did not see a computer, and I also know for a fact that my truck does not have O2 sensors on it, (well not any more) it does have the wires for them but are not hooked to any thing. but who knows maybe I just did not see the computer back there, if you say its there I trust you.

Thanks for all the help guys.

 

At some point, your truck probably had the simple electronic controlled carb. There was not really an ECU per say as it was more of just a simple control module. If someone has since swapped the carb, there would be no need for anything else that was used in the system.

 

I see. that is true, cause when I bought the truck the owner had replaced the carb with an edelbrock carb. I have another question for anybody who knows the answer. my fan only blows through the vents, so I do not have any defrost or bi-level. how do I fixthat and is it hard to do?