1983 "L" with emissions problems

[wv109323]

I have a 1983 "L" model 2.3 with a 1-bbl carb, auto transmission. The car is running rich. All plugs are black with carbon. The car has 85K miles. Also the exhaust is running cherry red from the rich condition and apparently the air pump is not being put into bypass when the throttle is WOT. The WOT switch is working but there is no voltage to it. The car has set 20 years
Also at a warm idle the RPM pulsates 500-1250 . I can not find a vacuum leak anywhere. Any suggestions? comments?
I replaced the PVC valve. I recently blocked the EGR valve with a plate between intake manifold and ERG valve. New fuel pump.
Gas mileage is poor at 16-18 MPG.
Would a clogged exhaust cause these symtoms?

 

[ethangsmith]

This could really be a multitude of things. But, yes, clogged exhaust can cause some bad problems. It sounds like you also have some other issues going too. I can't remember, does the 83 have a computer controlled carb and ignition or is it still Duraspark ignition? The way to tell if you are unfamiliar is the Duraspark has a vacuum advance on the distributor, whereas the computer controlled ignition has a grey module on the side of the distributor. A computer controlled carb would have a fuel control solenoid on it (red and white/red wires coming to it) and a throttle position sensor on it. If you've got a computer system, I would scan for codes, but I don't think the 83's had the computer. If not, I would start with new exhaust and a carburetor rebuild.

 

[wv109323]

Thanks ethangsmith. After I did some thinking I agree. The 1983 did have the Duraspark ignition and no computer.
The carb has a micro switch that is activated by the mechanical linkage at WOT. This switch along with a electric/vacuum relay is suppose to put the smog/air pump into the by-pass mode at WOT. The extra air ( caused by the air pump continueing to pump ) into the exhaust allows additional "combustion" to take place in the exhaust system causing the exhaust pipe to turn red hot.
My problem is tracing down all the associated components. Once the wires leave the micro switch they go into a tree of wiring that I can not trace. Any knowledge of where these components are located would be appreciated. Again thanks.

 

[hotcobra03]

A clogged cat can cause it to turn red as will muffler.my olds 442 had a 4bbl quad jet and the dump valve went bad that so carb can cause it.as to emissions you need egr system working .gases need to be recircleated .as old school system it will require everything working to pass test.the guy who used to help me in N.J. Would put in it was a rotary engine and ac on high .and if that didnt work we stick the tube in a different car. That was back yrs ago good luck

 

[ethangsmith]

I know on the early 80's cars, the Thermactor vacuum switch was located on the firewall. The relay was located behind the passenger side kick panel where the later cars had the computers mounted. None of the components are made anymore. I tried to make a rigup on my car like that, but couldn't get parts. Your only hope is a junkyard.