General 90 EPROM ECU in a 91?

[Ben]

I will, but I have a fairly new battery, and a VERY new mitsubishi alt.

 

[steve]

I also do not have power steering or A/C, and Do have a good, functioning ISC motor. But my idle drops to 500-600 when I turn the headlights on. and I have the idle set about 1000 rpm so it's a huge drop.

You can't have a 1000 RPM idle with a functioning ISC unless you have reprogrammed the ECU and then adjusted the BISS for the change. The stock ECU setting is 750 and the ECU will fight with you to change that unless you drive the ISC out of range with the BISS at which point the ECU can't control the idle speed anymore.

Or as we discussed you don't have the IPS connected correctly so the ECU doesn't know the throttle is closed and it's to maintain the idle speed.

 

[Ben]

You can't have a 1000 RPM idle with a functioning ISC unless you have reprogrammed the ECU and then adjusted the BISS for the change. The stock ECU setting is 750 and the ECU will fight with you to change that unless you drive the ISC out of range with the BISS at which point the ECU can't control the idle speed anymore.

Or as we discussed you don't have the IPS connected correctly so the ECU doesn't know the throttle is closed and it's to maintain the idle speed.

Dang you hit the nail on the head every time!!

My keydiver chip is on it's way here with a target idle of 950. and I still need to find someway to hook up a closed throttle switch. I think I'm going to use a wot switch from a nitrous kit.

 

[steve]

I still need to find someway to hook up a closed throttle switch.

If the casting is broken off you need a new TB since that not only holds the IPS but the IPS acts as a throttle stop to keep the butterfly from closing too far.

If it was just a missing IPS you can buy new one MD614216 or use a bolt and wire in a 2G TPS with the IPS built in.

 

[Ben]

If the casting is broken off you need a new TB since that not only holds the IPS but the IPS acts as a throttle stop to keep the butterfly from closing too far.

If it was just a missing IPS you can buy new one MD614216 or use a bolt and wire in a 2G TPS with the IPS built in.

I drilled and tapped a hole through the spot where the IPS would make contact and put a bolt in there. the head of the bolt meets part of the tb that held the IPS. it acts as a throttle stop.
How do i know where to adjust where the plate stops??
I really need another TB, but this one's been ported.
what's this about a 2g TPS?? I will look into this more.