I've been bringing a '83 Limited Edition back to life and all was going well until I put the car through inspection. The only problem was the belt to the air pump was loose and about to come off so since I was going to replace all the belts anyway I had my service guy do it for me. Before inspection the engine ran great even after sitting for several years, I had put nearly 300 miles on the car before this work was done and now it runs like crap. During acceleration the engine runs strong but when I let off the gas and cruse it runs very rough like it's out of time or running out of gas. It also idles very rough if at all. I looked at the plugs to see if they were fowled and changed them just in case, no help. All vacuum hoses seem to be in place. The car by the way passed inspection. Any suggestions.

Mike

 

im not sure dude, im right here with yaht though.
my car really idles rough.

 

Are you saying that it ran good before it was inspected, but not afterward? Or it ran fine before your man worked on it, but not after?

 

sounds like a cloged pump, take the belt off and see you it runs if it runs better its your pump

 

I think he is referring to the air pump, not fuel pump...

 

Any car sitting for 3 years can manifest all sorts of issues The first being being the fuel breaking down, losing octane rating and and the fuel itself thickening from the volatiles evaporating and turning into a varnish like substance. This thickening can reek havoc on the entire fuel system. The thicker/gooier part of the fuel leads to deposits that will cause deposits, plugging screens, filters, jets and passage ways for fuel.

While you're checking for plugged filters, don't forget the ones around the banjo bolts that hold the supply/retutn lines to the top of the carb. Run a can of Seafoam through fuel tank too.

 

The engine was running good before inspection which is when the belts were changed. The fuel system has been redone all new hoses, filters, fuel pump and a cleaned and sealed gas tank.

The engine runs strong while accelerating (4,000-6,000rpm) than runs rough when cursing (30-40mph/1,500-2,500rpm)and barely runs at idle.

mike

 

Look for vacuum leaks, sometimes a hose will get knocked of while work is being done without being noticed. There is a rubber hose that goes down behind the carb near the passenger side firewall that is very hard to see, it is a large vacuum hose that rots out fairly quickly because it is down by the exhaust manifold, you may not have noticed this one or others, there are so many.

 

Thanks, I have looked over the vacuum hoses (As many as I could find and identify) and all seem in place. It's been suggested that the coils or coil may be the cause. The plugs are dry so it looks like I'm getting spark. Any thoughts?

 

Did you check your fuel filter under the car to see if it's partially clogged?

 

New filter, and pump. New fuel lines as well. The more acceleration the better it runs, just won"t cruse or idle.

 

I guess at this point, I'd try taking the belt off of the air pump...

 

My SE had similar sounding issues, running fine when on it, backfiring and sputtering when off or steady and under a low RPM. I thought it sounded kind of neat actually. Failed a smog test (first time failed in 4 runs=8years) and when I took it to be checked, they (stealership) did something called a port scrub. Cost me $800, I didn't know any better or what to do, but it stopped all the issues.