Hello All,

Just joined your Forum. Been having a problem with my '93 Flairside.

A little history:

Bought used two years ago with 150,000 miles showin'......Check Engine light came on and would go off periodically right after purchase.

Replaced O2 sensor, new plugs, wires and rotor to correct engine performance problem. Didn't fix it..........

Took it to a local engine analizer guru...........

Found bad sensor in engine management circuit. Replaced it.

Ran.......Okay for short while.......(50 miles)

Took it back for misfire. Found bad (new) plug wire. Replaced it.

Engine would still periodically have a slight hesitation and misfire.

Took it back to guru. He discovered NOTHING! Said that my Check Engine light was triggered by a code stating that there was a loss of comunication to the main computer.

His fix? Recommended replacing the WHOLE wiring harness but, didn't sound confident that I'd find a replacement at the junkyard worth installing.

His reasoning is that during troubleshooting the cause of the light and consequent code displayed, that there was a connector that wasn't staying connected together for good contact between the pins. He basically left me with this delima.

His suggested remedy would possibly cure the problem but, where would I find a replacement harness......and does this sound like a solution?

I can't believe that replacing the harness is the solution. There's got to be a more cost effective solution, besides, I can't afford a new one.

The engine in it, has been abused by the previous owners. Oil pressure on gage seems to be above midways of gage. Doesn't run hot but, it's got a loud main bearing (deep) noise coming from it on intial start up and a ticking lifter on the left bank. So, when my budget permits, I'll pull it for a rebuild.

In the meantime, what can I do to replace all of the connectors that are installed on the factory harness and is this the problem?

I still get a Check Engine light.

My interior fan/blower output switches over from the dash and floor circuit to the defroster circuit when using the airconditioning and excellerating. Like it's a vacuum issue. I've sprayed the vacuum hoses under the hood without finding any problems.

The Check Engine light goes out by the way..............

I'm at a loss on what to do next.........short of buying a new truck but, I'm not going there. I love this one and want to keep it.

Any idea's on what my next move should be will be appreciated. I have limited knowledge of these newer trucks. Way to many sensor's.......LOL! Give me back my simple carburated engine without.........the computer and I'll be happy. But, they don't make 'em like that any more.

Thanks All,

Coster
Bonaire, GA

 

Don't think harness is cause, maybe something like cap or coil intermenent.
replace PVC
A/C think check valve to vac tank

 

Thanks for the input cctxfish......

Since I've already replaced the distributor cap, it's unlikely that the problem woould be that. Although it's possible. I'll pull it to check for cracks.

I've read about the check valve for the vacuum circuit. The thing is, I don't know what I'm looking for. I can't find a check valve in any of the vacuum hoses that go to and from the canister/tank. Could it be that the previous owner removed it without reinstalling it? That's the only thing I can think of. It's not a very big valve is it? About one inch long and three quarters of inch in diameter?

Thanks again..........

Coaster

 

Look for any type of moister in dist.
check valve is about 1" dia. and 1/4" thick. heck just add one and check for any leaks in tank and hoses.

 

Thanks for the tips cctxfish.

I'll get a check valve and install it. The thing is, which hose should it be installed in? Before the tank so it will insure that the vacuum pressure is kept in the tank and is not drawn out for engine use. Correct?

Later,

Coaster

 

on the passenger side of the engine on the fender well there is supposed to be a tomato can looking vacuum tank check to make sure it isnt rusted out at the bottom seen that alot

 

Hose going to engine, suck on valve the side you can draw air goes to engine side.

 

Good point hockeyhitman69. I haven't removed that can/tank yet but will do it and check for holes from rust.

Thanks for the tip.

Coaster