Idle Issues :[

[BlackDynamite]

Ok, i just got through rebuilding a 89 targa NA auto. New everything except the injectors, alternator(from a 89 turbo), and the fuel damper (From a 89 turbo).


The car runs and drives BEAUTIFULLY! But the idle tends to jump around. It normally idles around 1500 rpm.(Checked timing, 10º at NOT, with the jumper) But i drove it around the other day on the break in period and it started to fall on it's face when i was coming to a stop, so i bumped into neutral. It sounded like a v8 with a serious cam...LOL....New wires, Rotor, Cap, and Toyota plugs. Bumped the throttle, and it still did it...Then raised it to about 3500 RPM, and held it. Let go and It went back down to 1500. Idling nicely....

I wanted to check the idle screw, but it wasn't there.... LIKE, there is no hole for one, like it doesn't exist....I've had previous models 88, 87, 86.5, and all have had an idle screw. AM i missing something? Did they change the throttle body again!? I know they changed between the TPS sensors, but wtf...

 

[mkiiichip]

You are correct the later models have no idle screw.

What does "10* at NOT" mean?

Youll notice on the under-hood emissions label the idle is supposed to be like 700-800 rpm (cant remember exactly). If idle is not correct timing can not be properly set. DO NOT try to manually adjust idle you will only be covering another issue.

Question: does the timing change when you put on the timing jumper? or does it stay the same with or without the jumper (at idle).

 

[BlackDynamite]

with a timing light and the jumper, i set the timing to 10 degrees, at normal operating temperature.

Nothing changes on the idle, when i make the jumper. But the ecu light is blinking. It was constant blinking but i checked earlier and i have a code 51.

Which is No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check. Now this car DOES NOT have A/C. All components have been removed.

 

[mkiiichip]

normal operating temp right

Nothing changes on the idle, when i make the jumper.

but does the timing change at all?

 

[BlackDynamite]

If i remember correctly, no.

 

[mkiiichip]

TPS inspection and likely adjustment or replacment.

 

[BlackDynamite]

Roger. I figured it was. Can i use a Turbo TPS? They are the same year. And both TPS's Look i identical.

 

[mkiiichip]

That i dont know (but i think they have a part number on them), if proper inspection says yours is bad, new is best. It is very common for the IDL contacts to wear creating your issue. Your ECU thinks the throttle is open slightly, raising the idle and advancing the timing.

 

[jetjock]

TPS inspection and likely adjustment or replacment.

^ This. Timing cannot be set with the IDL contact open. Nor will the idle speed control system function.

 

[BlackDynamite]

ok, so i got the turbo TPS, which was in great shape, and put it on a 86.5-88 Throttle body i had laying around, with an idle screw. Made sure the Idle screw was all the way in. Installed, and started it up. It ran the same way.... I did the jumper to make sure of codes. It was blinking fine. Then the 51 popped up....Then it went away and started blinking constant again. So i adjusted timing a little. I revved it up to about 3000RPM for about 10 seconds and it idled perfectly at 800. Drove it around and it did fine. Jiggled every wire i could think of.... Even pulled off the tps sensor connector. it didn't throw the 51 code, but idle poorly.......plugged it back in and it ran fine.......still no code....I'm LIKE WTF....also changed out the changed out the vane meter just be sure, when it was idling poorly. But same thing. I dunno....i was thinking maybe there was some bad gas....or some trash in the fuel lines...possibly a sticking injector, or fuel pressure regulator.

---------- Post added at 08:13 PM ---------- Previous post was at 08:12 PM ----------

Or even poor wiring....every clip was broke when i got it... :[

 

[87nasupra]

Don't wanna make it sound like an ass towards you but, have you checked all of your intake/accordian hoses? My 87 and 91 n/a did that...I saw a slight cut in each intake hose that was causin the same type of problems. Just a thought Good luck

 

[TURBO TESLA]

thas a good question every once in while my 7m in my cressida idles down and almost stalls this doesnt happen very often but i shut it off and fire it back up and it hauls ass idk by the way can i use that turbo/at ecm with my nat on my black 87 ?