'87 Caprice engine misfiring and smelling rich and lumpy idle! = help!

Hello Chaps.

Just wondering if any of you could offer advice on my 1987 Chevy Caprice.

She mis-fires at times, you never know when its going to happen, its never on a certain road or specific speed, its almost like a silent back-fire (if you know what I mean)

On idling in traffic or at a stop sign, her idle is rather lumpy, and at times makes the car rock from side to side.

Fumes smell rather rich, and they are very over-powering. Its bad at times.

She's not: over-heating, using oil or water But, she has started guzzling fuel, a lot more than normal.

Any ideas or suggestions are gratefully received.

Thankyou in advance.

Kurty.

 

I'd look at the simple things first:

- Spark plugs, plug wires, coil, ignition module and pick-up module.
Any of these could cause what you describe. If possible, watch the engine run iin a dark garage; if you're lucky, you'll be able to see any arcing or cross-fire between plug wires or from plugs to block.

- Sticking float in carburetor (any wetness on top of the carb or around the carb base/gaskets is a good indication that the float is not working properly)

 

Thanks JMT

Interesting what you say, - although I should have also noted that she came back from a service 2 weeks ago, - I have taken her back and the garage owner cannot remedy this. He's a nice fellow, and I don't wish to upset him, I just won't go there again.

 

I would check for a sticking choke first. That would explain the misfires(fouling plugs) and the rich fuel smell. If the choke sticks that itself can make it backfire. And if you had it in for service a choke pull of isn't a "normal" service item. Unless you took it FOR this reason

 

This isn't going to be simple and if it continues will only get worse and start taking things with it.....your catalytic converter in particular. Very carefully inspect the engine compartment when the car is running and look for vacuum hose problems, broken electrical connections, etc.

If nothing is found, a scanner would be beneficial, but you can also pull trouble codes from the computer with a jumper wire. Once you pull the codes, you have to prioritize them as some problems will cause other components to set codes. Then, there is a specific diagnostic tree to follow for each trouble code. Some of the trees can be several pages long.

Pull the codes and report back. Only then will someone be able to TRY and assist you.

 

You have been given very good trouble shooting advice all around. As for the shop that serviced your car, and if I understand this problem was not there before you had it serviced, and the nice guy can't figure it out....Yeah, I'd upset him in front of other costumers. Sorry if I sound harsh, but that says a lot about the shop.

Hope you get this sorted, again you have been given good trouble shooting advice.

 

Many thanks for your help chaps.

She's booked into another America Car specialist here in my home town now.

So see what this guy thinks, - hope its sorted though as I think this will (as suggested) be abit of a snowball effect!