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86 ESi-R TPS/ISC Reset troubles


Coke
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I followed step by step in the FSM, then after I set the TPS.... I go to start the car make sure idle is correct after I plug the ISC connector back in, the idle is much higher, like 1200 RPM.

 

Am I missing something? Like I said, I followed the procedure step by step. Am I supposed to adjust the idle AGAIN, after the TPS set? Doesn't seem right....

 

http://www.starquestclub.com/forum/index.php?showtopic=27979

This is the same as what the FSM says to do...still confused.

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I forgot what I did on my '86 ESiR, but when I followed the book (several times) it would idle high like that. I studied the procedure and saw a step that didn't make sense, so I tried what did make sense to me, and it idles and runs great now. I would look at the procedure and change a step. It was something about when to turn the key back to 'on' I think. I'd have to look at it again, but it was night and day and ran much better.
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Yes! That's exactly the same confusion I ran into. I'm glad you understand my frustration. Can you remember what step you changed?? I'm not good with stupid stuff. lol
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Follow the steps exactly, I've done it this way on several 86's and they idle like a dream. You should sweep test the TPS, and check your ISC for smooth operation.

 

1. Engine must be at operating temperature. All accessories OFF, front wheels in forward position (Minimal RPM strain from power steering pump)

 

2. After engine is warmed-up, turn ignition off.

 

3. Loosen accelerator cable so it is completely slack

 

4. Loosen TPS screws and rotate TPS all the way clockwise and secure screws

 

5. Turn ignition switch ON for more than 15 seconds then turn OFF . (This sets ISC to it specified position.)

 

6. Disconnect ISC motor connector

 

7. Start engine

 

8. Set idle speed with adjustment screw. (850 RPM +/- 100 RPM)

 

9. Stop engine

 

10. Connect voltmeter to top terminals on TPS connector. (See page 14 -12 of Factory manual)(http://www.starquestclub.com/forum/style_emoticons/default/cool.gif= Black & (GW=Green w/White stripe) Mike C likes to pull the rubber insulator out of the top of the connector to get a good connection on the wires. I like to use T-Pins to probe in through the top of the connector then attach with alligator adapter clips to the voltmeter

 

11. Ignition switch ON do not start engine

 

12. Loosen TPS screws and slowly turn TPS counterclockwise/clockwise to set correct voltage.

 

13. Set voltage to 0.45 - 0.51 ( optimal=0.48 )

 

14. Tighten TPS screws without changing setting achieved in step 13.

 

15. Snap Throttle plate ( pull up on "throttle lever" vertically and let go ) (use throttle lever not cable incase cable kinks or binds)

 

16. Re-check and if needed re-adjust TPS to correct voltage

 

17. Re-connect ISC motor connector.

 

18. Start engine

 

19. Adjust idle to (850 RPM +/- 100 RPM)

 

20. Shut engine off.

 

21. Turn ignition to the ON position for 15 seconds then turn to OFF position

 

22. Tighten and adjust accelerator cable - 1+ mm free play

 

23. Make sure ISC control switch (just) touches stopper on throttle lever (lever accelerator cable is attached to)

 

24. Start engine

 

25. Confirm Correct Curb Idle Speed

 

Steps 1-8 are resetting the lowest idle point in case of ISC failure. Then you set the TPS to the correct position. Then you "fine tune" the idle position in step 19. Step 25, confirm correct idle speed... meaning if it's not right, do it over again. Sometimes it'll take a few resets to get it just right... but it sounds like you're not completing the entire instruction list.

 

Doing any of these incorrectly will result in an incorrect idle... assuming you've done a sweep test, checked the ISC for proper operation, ensured proper grounds for the idle nose switch, have a CTS in the correct ohm range, checked the injectors for leaking, and don't have any vacuum leaks.

 

-Robert

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Yeah, I don't have my '86 manual handy, but I don't see the conflict in what Robert posted. That procedure is not the same as the manual I used. I'll look at what I used and post it soon, with the change I made to it. I really think it was a misprint in the manual because it won't work the way they laid it out.

 

It looks to me that what Robert posted should work fine.

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Yeah, in the FSM's step 15/16, it merely says to reconnect the ISC and "make sure the curb idle speed is correct". Coke was using the list posted, however, so in step 19 it clearly says to adjust the idle after reconnecting the ISC.

 

One thing I'm remembering that I might do after reconnecting the ISC, I let it adjust itself by turning the ignition to the on position for 15 seconds... and then start the engine.

 

17. Turn off ignition switch. Re-connect ISC motor connector. Turn on ignition switch to on position, listen for ISC motor to adjust itself within 15 seconds.

 

18. Start engine

 

19. Adjust idle again to (850 RPM +/- 100 RPM)

 

20. Shut engine off.

 

Give that a shot, I'm thinking this might help. When I do TPS/ISC resets, I've done them so many times I'm usually "in the zone" and tune by feel... LOL...

 

-Robert

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if it idles good you can back the screw off a bit on the 86. i don't have an isc but mine started to idle up a bit after sitting awhile. a little oil on the spring and cable at the tb took care of it.

glad you picked that 86 up, i was thinkin about it. nice car.

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Thanks guys. I did it the way Robert said, and it worked out. Unfortunately, I still have a miss at idle when warmed up. On cold start, it idles like a top. Once warmed up, it has that random (and mild) miss at idle. I did check the diagnostic port next to the air canister and it appears to be throwing an o2 sensor code when warm. I tested the sensor's readings while running with the ECI Checker and it's voltage outputs appear to be normal? Not quite sure where to go with that. I kinda want to rebuild the distributor, too....for good measure.
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