Idle Question
 

Hello. I am new to rotarys and have a couple questions.
Vehicle: 1987 13b N/A coupe (base) 95,000 original miles

When I bought the car the Idle was horrible. I changed all 4 plugs (leading and trailing plugs installed correctly) and put on a set of 8.5mm wires and changed the fuel filter. That helped a lot.
After that the car still had a slight but random misfire throughout the rpm range, so the tps was adjusted.
Now the car still has a very, slight but random misfire. and it refuses to keep the same idle speed each start-up. one time it may be 1000~ another time it may be700~ but in that range.
So, my question is thus:
Is there any "tune-up" item I missed or is this a possible vacuum leak issue?

also my reverse lights do not work and the shift up indicator has stopped working, is there a chance that cleaning the 5th/reverse switch will fix thoes two problems?

Thanks
-Pat

I don't think you can clean the internals of the fifth/reverse switch. Try holding the shift lever in reverse and put pressure on the lever from side to side and see if the reverse lights come on momentarily while doing that. Check the fuse yet??????

I did not see a fuse listed on the fuse box.

Lights did not come on while trying your trick.

Have you checked to see if the computer is throwing any error codes? Sounds like it could be a bad TPS.

TPS or control on top of the TB

If the TPS is outputing one volt dc when the engine is fully hot, then it isn't the TPS.

Does this odd idle rpm that changes each time you start the engine, happen after the engine is fully HOT or are you doing this with a engine not fully warmed up?

Could be a misrouted vacuum line at the front of the throttle body. Three nipples.....three different places to go with 'em. On the rear there are two nipples with two different places to go.

ON the front, if the two SMALL vacuum lines are crossed at the throttle body, that can cause a irregular idle. Only one is vacuum. The other comes from a source prior to the throttle plates.

Here's a site that's fairly reliable for setting TPS and checking codes etc.

If at idle you have a slight missing sound, try this. Go to the variable resistor. Look at its screw and note where it is right now. Then with a fully hot engine, turn the screw clockwise to richen the mixture. The pooh, pooh should be reduced when doing that. The screw only turns three quarters of a full turn. Don't try going past the *stops* in each direction.

METER fuse powers the reverse lights.

Sounds like time to crawl under the car and check the wiring to the fifth/reverse switch. Check for power (only one wire has power) and continuity of the SWITCH wires when in fifth then in reverse. I don't remember. It think there two green and two red wires. Two reds go to one switch and two green to the other switch in the switch. Get me? Get on the two red with a meter and when in the right gear you get continuity. Get in neutral and no continuity. Same with the other set of wires.

Thanks for all of the help.
I will do some more testing with the instructions you provided to see if it helps.
Thanks again.


To answer your question Hailers, the idle varies after the engine is hot