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Engine Sputters

Old Mar 15, 2012 | 11:24 AM
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Engine Sputters

I just got an 86 GS with 59,047 miles and has 100% original engine/powertrain. It is constantly sputtering and accelerates/decelerates (revs up/ revs down) when idle ... It accelerates strong with rarely a missfire when driving until I idle.

I replaced the Mass Air-Flow sensor, Air filter, Spark Plugs, Spark Plug Wires, Battery, Installed a Voltage Stabilizer with new grounds, replaced BAC and Temperature Air Sensor, replaced Fuel filter with fuel pump, the coolant reservoir and Sub-Zero reservoir are full, had a professional fuel system flush. I'm STUMP!!!

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Old Mar 21, 2012 | 10:39 AM
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I really need some guidance with this issue... please?
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Old Mar 21, 2012 | 06:16 PM
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I don't know if those models have a TPS. If they do, then I recommend to check it and adjust/calibrate it.
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Old Mar 21, 2012 | 07:13 PM
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Originally Posted by Eduardo Santos
I don't know if those models have a TPS. If they do, then I recommend to check it and adjust/calibrate it.
Boom..right on the money.
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Old Mar 22, 2012 | 09:18 AM
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Excellent! That is on one the few things I have not checked or replaced... thanks for the lead. I'll post the result after trying this

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Old Apr 2, 2012 | 04:47 PM
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Well, I replaced the TPS and I'm still having the same proplem... I guess the only thing left to replace or check is the Throttlebody and Injectors.... I will most likely start with the throttlebody. Let me know what you guys think!
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Old Apr 2, 2012 | 05:25 PM
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Well, you replaced the TPS, but did you adjusted/calibrated it? If you just put a new TPS and don't calibrate it, I don't think it will work properly...

Last edited by Eduardo Santos; Apr 2, 2012 at 05:35 PM.
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Old Apr 2, 2012 | 06:20 PM
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Make sure your TPS is calibrated properly.

Check for vacuum leaks, just spray propane or carb cleaner on all your vac lines, and see if the idle changes, if it does you have a vac leak.

Spray propane/carb clean around intake gaskets, to check for more leaks.

Inspect the intake passage between the MAF and the Throttle body for holes or leaks.

Get some throttle body cleaner and a rag and clean out the throttle body, especially around the upper butterfly valves. If its all clean and shiny, then check the adjustment for the upper butterflies and check their clearances. (you want to concentrate on the top 2 valves because those are not monitored by the TPS. So if too much air is getting by them, you will get essentially a massive vacuum leak.
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Old Apr 3, 2012 | 05:36 AM
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Originally Posted by k4killer
Make sure your TPS is calibrated properly.

Check for vacuum leaks, just spray propane or carb cleaner on all your vac lines, and see if the idle changes, if it does you have a vac leak.

Spray propane/carb clean around intake gaskets, to check for more leaks.

Inspect the intake passage between the MAF and the Throttle body for holes or leaks.

Get some throttle body cleaner and a rag and clean out the throttle body, especially around the upper butterfly valves. If its all clean and shiny, then check the adjustment for the upper butterflies and check their clearances. (you want to concentrate on the top 2 valves because those are not monitored by the TPS. So if too much air is getting by them, you will get essentially a massive vacuum leak.
Just make sure the engine is not too hot when doing so, or it may caught on fire.
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Old Apr 3, 2012 | 10:11 AM
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Lol yeah, don't spray Carb cleaner on the exhaust XD.
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Old Apr 13, 2012 | 11:17 PM
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try this www.aaroncake.net/rx-7/grounding.htm
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