Wonderboy893

I own a 1986 Chervolet Sprint
I bought it a few months back
It was almost in perfect condition .. spotless inside and out (including under the hood) .. and only 37,000 miles incredibly ....


Well, it was driving fine for about 2 weeks, then all of a sudden started doing something strange

I will be driving down the interstate .. and all of a sudden the car just sorta stops .. and everything quits on me ..

sometimes, if I hold down the gas pedal, it will kick back in and backfire, and I can start driving again .. other times, it will just shutoff and after a minute or so I can restart it ...

Well, I took it to the local chevy shop ..
And here's everything that they replaced:
1. Sparks, Plugs and Wires
2. Fuel Filter
3. Fuel Pump
4. Checked all the gas lines
5. Carborater

They said at one point, you could see that the little glass thing on the side of the carborator wasn't getting gas when it would cut off .. well, now it's getting gas .. but it still has the same problem


Today they said that they give up .. and they're giving me the car back, and I don't have to pay anything ..

So my question is .. what else could I possibly replace that could correct this problem?

I really like this car, and would love to actually get it going again ..

Do any of you guys have any ideas?

blazee

Check your coil. Ignition wires. Computer.

The backfire is a result of your car coasting while in gear. The engine continues to turn, which keeps dumping gas in the cylinders, the vapors build up in the engine and exhuast pipes, when the engine restarts all these trapped vapors ignite causing a backfire.

The backfire lets you know that the problem isn't in the fuel delivery system. Which means that the Fuel filter, Fuel pump, gas lines, and Carburator were not the problem.....also means that holding down the gas pedal does nothing, you just get lucky sometimes and it restarts.

The problem lies somewhere in the ignition system. The ignition is turning itself off and on. This could be caused by a faulty component or even a loose connection. (don't be confused I'm not refering to the ignition switch, often called the ignition, I'm talking about the whole system)

The ignition system includes the supply from the battery, the ignition switch, relays, fuses, coil, distributor, points(if equiped), rotor, distributor cap, plug wires, and spark plugs. Which are all controlled by the computer, although in 86 it may just be a brain and not an elaberate computer system. It sounds complicated but it isn't that bad.

tom3

Usually this type of failure is the ignition module. Not sure how the Sprint ignition is set up but there will be a module that controls spark and timing, and when they fail, often it will be when they get hot. After it cools a bit it will run normal for a while. This is where I'd start anyway. Autozone can test many of these and they'll usually test several times to heat it up.

public

Also check for a loose ground. This can mimic a fuel filter.

__________________


Yes, I am retarded.

Mikes Mechanics

I have seen a few of the Japanese cars have this simalar problem. You said that the site glass on the carborator shows that there is no gas when the problem happens.

This could be one of 2 problems they had back then. First the Japanese put a wire mesh screen inside the carb at the fuel inlet to stop dirt particals that get past the filter. Sometimes they will clogg and stall the engine only at high rpm. The dirt will block the screen thus starving the engine but there will be enough room for a little fuel to pass by and keep the engine running at low rpm. If this is the case just remove the screen.

Second there is a fuel cut off solenoid on these carbs. It could be failing when the voltage is raised at high rpm. This is caused by the higher voltage over heating the coil in the solenoid and shuting it down shutting off the fuel to the carb. Since this solenoid is so small it cools down quite rapidly and starts working again till it heats up again.These solenoids are never cheap and no way of testing them.

I hope this helps you.