After test-driving the code “60” didn’t return. While sitting in park the engine ran smooth but as soon as I applied the brakes the engine started to run rough, a hard miss, like I lost a cylinder or two, just like when I put it in drive or reverse. The car drove and shifted fine, on acceleration through, again with the rough miss. any Ideas? Oh Ya the TPS tested good, (0.5v closed/4.5v @wot)
Trouble code 60 implies problems in the cruse control circuit. Isn’t the cruse control vacuum influenced?
Wouldn’t the brakes be affected if the booster was bad?
I agree vacuum is the culprit.
Needle in the haystack time.
Well, you can try inducing the code 60 again if you want.
I still don't have a service manual, but I'm pretty sure code 60 sets when the driver sets the cruise control but the transmission pressure switch indicates that the car is in park or neutral. When the code is set, the cruise is disabled.
Usually this code comes in a pair with code 91, for a PRNDL switch problem. Just to be safe, you should double check that the PCM signal for the PRNDL switch is correct. It could either be bad or misadjusted. However, since there is no code 91, it's probably fine.
Either this code was set accidentally by you physically bumping the cruise while in park or neutral (most common) or the pressure switch is actually bad. Take the car for a ride and try setting the cruise, see if the code sets again.
The cruse control disengages sometimes after the engine is at top temp and wont activate until the next time the car is driven. It’s been an intermittent issue for a while now. Also the last diagnostic, running through the switch test, step #5 “shift the transmission lever into reverse and then into park and observe code .7.5.” took a few times before it displayed the switch OK code.
Would a bad pressure switch cause internal pressure to increase causing fluid seepage at the axel dust seals?
Well out of frustration I went back to square one trying to figure out what the hell.
1. The spark plugs. All 8 were in good condition with no re-gapping required. (I replaced them a while ago)
2. The distributor. The cap was shot, full of carbon, center pin gone! And the terminals corroded. The rotor still had a batch number stamp on it? Factory? Replaced with new OEM along with new cables.
3. Test drive. Started right up, still idled rough, ran worse after reaching operating temp. Surging and then Stalling.
4. Check for codes. NO CODES! Hmmm
5. Check EGR. Some carbon but moved freely. A hand vacuum pump test showed good.
6. Check vacuum hoses. All in good shape and property routed. (I replaced them a while ago)
7. Check throttle body to manifold seal. Was able to get about 1/8 turn on two and almost half a turn on the third.
8. Check ICS. Operational.
9. Check PVC. Operational.
10. Check air horn damper. Operational.
11. Check TPS. I had checked this recently and was OK, but I re-tested it again with using a new multi-meter. This time the readings showed .5 volts on the idle and 3.9 volts at full throttle. Recommended is 4.5 volts at full throttle.
This is where I’m stuck! I cant seem to locate a replacement TPS for the 83 model. I searched my local U-Pull yard and found 4-84 HT4100’s. The TPS’s are different, the harness plug pins are reversed and mounts vertical rather than horizontal.
Until I can locate one I’m unable to test drive. Although I did locate a major ignition problem as well as a loose throttle body, I’m sure I’ll see improvement.
I wouldn't jump straight to tranny, it might be something simple like TPS
ehall! The TPS along with fried cap and rotor as well as a loose TB. Thanks for setting me thinking in the right direction.
Now the idle is to high, probabley the reason it ran at all in the first place.
Next step! Adjusting the ISC...
Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
Re: Transmission acting funny
I presume the ten degrees seen was with the green connector unplugged behind the distributor? 4 pulses means the ISC is misadjusted and is searching for the proper opening angle of the throttle. The ISC is the most misunderstood item on this engine! With the engine running and the throttle held slightly open, push down forcefully on the ISC shaft and keep applying pressure till it fully retracts, bottoms, within the unit. Then QUICKLY unplug the wires to the ISC. Then gently lower the throttle arm. It should be barely running somewhere around 400 to 450 RPM. Then with a .060 inch feeler gauge placed between the throttle arm and the ISC shaft adjust the arm to get that .060 inch gap. Shut off the engine reconnect the harness to the ISC. wait 10 seconds and restart the car. The code related to the cruise control and the gear shift out of position is usually related to worn out and/or missing shifter linkage bushings. Most common at the shift lever at the trans itself. Too much play in the shifter rods and cross shaft above the driver side exhaust manifold will cause faulty readings on the back up light switch and cruise control intermittant operation.