Gerald Kamenski Posted April 5, 2022 Report Share Posted April 5, 2022 (edited) I have an 87 Starion finally up and turning over. Runs beautifully in higher rpms but clunks out when off the accelerator. The AFS is all connected and a fresh, cleaned out fuel system. The timing is 10 deg btdc but besides that I have no idea what could be causing this. I'm open to any suggestion cus I'm at a roadblock with this project. Update: I saw the TPS/ISC Reset post and the MPS and TPS sensor voltage readings were all good. I didn't know how to set the idle speed so I'm still figuring that out and I didn't run jumper wires to simulate the closed IPS. Another Issue is that I cant tell if the TPS is "zipping" or "oscillating" as the post says. Its more like a "whirring" sound which I think is the bad one of the 2. There may be a rocker cover gasket leak that is being addressed and will perform a vacuum test with carb cleaner to find any leaks that could be in the system. Edited April 10, 2022 by Gerald Kamenski Link to comment Share on other sites More sharing options...
GoldStar Posted April 5, 2022 Report Share Posted April 5, 2022 What else have you tried? Link to comment Share on other sites More sharing options...
Turbo Cary Posted April 6, 2022 Report Share Posted April 6, 2022 Did you try a TPS/Idle reset? Link to comment Share on other sites More sharing options...
Caliber308 Posted April 6, 2022 Report Share Posted April 6, 2022 If you have never done the TPS/ISC reset here is where to go. You will need a multi meter that is digital. FAQ Section, Fuel/Ecu System. TPS/ ISC Reset (87 -89) by KO. Good Luck, Bill Link to comment Share on other sites More sharing options...
TexasQuest Posted April 7, 2022 Report Share Posted April 7, 2022 I highly recommend performing the TPS/ISC reset. Link to comment Share on other sites More sharing options...
860QuestTuner Posted April 9, 2022 Report Share Posted April 9, 2022 The procedure for the tps reset is in the how to section under fuel/ecu. If you read through and get everything prepped before you start can really help, just inspect the wires well and be careful with the old connectors and idle control. I would also check all piping connections, especially behind the mass air sensor Link to comment Share on other sites More sharing options...
GoldStar Posted April 9, 2022 Report Share Posted April 9, 2022 5 hours ago, 860QuestTuner said: I would also check all piping connections, especially behind the mass air sensor Definitely do this. I'm running into the same issue (won't hold idle coming off throttle, super rich AFR when it does idle), and I recently figured out that my 1g DSM blow off valve is causing a vacuum leak. As soon as I plug the "horn" opening with my hand, it holds idle great and AFRs go right back to stoich. Link to comment Share on other sites More sharing options...
Caliber308 Posted April 9, 2022 Report Share Posted April 9, 2022 A lot of things will cause a car to drop at idle and die. To check for a vacuum leak start the car, at a warm idle spray carb cleaner on all hoses and connections, if you hear a idle increase, that is most likely where the leak is. Try the easy things first. I would still do a ISC/TPS Reset. Bill Link to comment Share on other sites More sharing options...
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