90 throttle body/isc

[Custom GSX]

Hey guys I just had a few questions on the 1g throttle body's. I have a 90 eclipse gsx and have found that everything is different from the 91-94 1g but I had got a 91 throttle body to replace mine but have been reading that it can't be done or that's it is difficult.

Q1 can you swap the throttle bodies with sensor? Even re wiring sensors?

Q2 is there any benefit to going to the 91 tb for my 90?

Q3 is there any benefit to removing the FIAV ?

Or should I just look for a isc to fix my idle issue. 2k cold and 1300 rpm warm???

Thanks for any tips and answers guys!!!!!

 

[PaqueDSM]

Do you check yours??? What´s exactly bad with your throttle body?

 

[WES_393]

Q1 can you swap the throttle bodies with sensor? Even re wiring sensors?

Yes, you can install a 91-94 throttle body. It's not worth it IMO. Check out the link below.

http://www.dsmtuners.com/forums/articles-intake-exhaust/301466-1990-swap-91-94-throttle-body.html

Q2 is there any benefit to going to the 91 tb for my 90?

FIAV block-off and easier to find/cheaper ISC motor.

Q3 is there any benefit to removing the FIAV ?

You can remove the coolant lines, so you won't have 200* coolant running to the throttle body.

Or should I just look for a isc to fix my idle issue. 2k cold and 1300 rpm warm???

Have you tried adjusting the idle? Have you checked for vacuum leaks? The vast majority of idle issues are caused by those two things, not a failed ISC motor.

http://vfaq.com/mods/BISS-1G.html

 

[Custom GSX]

So I did a EGR delete and plugged all vacuum me lines. But befor I did this my idle was surging when warm and coming to a stop. Then it quit that and just started idling real high. Started at 1700 rpm and then I adjusted the tps and only got it to 1300rpm. So there's my dilemma. But I got a free 91 throttle body with sensors.

 

[BoostedBeaver]

There is no reason to throw a complicated part at the car when you are not sure what is wrong. Troubleshoot the part (sensors, BLT, ect) to find the cause and then replace the part that is not opperating correctly. This will save you time and money in the long run.

Robert

 

[Custom GSX]

Already done the bot test which is good. I haven't got a logger to check tps % and or voltage on isc. But I'm in no hurry. This car is a weekend warrior if that (600 mi a year). So I'm just trying to get feed back on if there was any gain besides more available sensors to this swap. Plus free parts are free parts. But thanks guys for the in put. And with me eliminating the cruise control could that of had any effect. I know the cable has very min slack befor pedal is engaged so its not holding it open more then it should.

 

[OakStreetTuner]

Have you adjusted the biss screw? I have rpm surge coming to stops and it helped my issue greatly.

 

[Custom GSX]

So I know what the screw controls but how much can it actually change with in the idle?

 

[WES_393]

So I know what the screw controls but how much can it actually change with in the idle?

It can change a lot, the BISS screw is what sets the idle. Hence the name Base Idle Speed Set Screw. If your BISS is way out of adjustment or has a missing/damaged the O-ring, then the ISC will have to adjust to compensate. The ISC can only move so far before it's completely closed an can't adjust the idle anymore. That's the point of grounding the ECU pin in the engine bay before adjusting the BISS. It locks the ISC in the middle of it range so once you get the idle to the correct speed the ECU has full control. It's all in the VFAQ link I posted.

And trust me, I had huge idle surge issues when I first got my DSM running. It took 10 minutes with a scan tool and a screw driver to get it purring at 700rpm.

 

[Custom GSX]

Cool that should work for me. Next question since I tried compinsating with the tps, which is all the way decreasing the idle. What will that effect with the biss?

 

[WES_393]

Before you adjust the BISS, I would get the TPS back to 0%. The idle is steadied now because the TPS is giving a false signal. Otherwise you would be surging at anything above 1500rpm. But overall the TPS has nothing to do with adjusting the idle speed, you just want it at 0 when idling.