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Car is hard/ impossible to start when warm.

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Hi, I have recently wired up a Haltech PS 1000 on my Corolla 7AFE engine, everything works well it starts just like stock when cold and seemes to be running like it should. But there is this one thing I just cannot figure out.

After a drive lets say 30 minuts when i stop the car it wont start again. I have traced the problem to be the injectors not firing when when the engine/ecu is warm, if the car cools down for 10-30 min. then the injectors starts to fire occasionally every now and then and the car will starts but is hard to start.

The ecu is reading both trigger and home signal when this problem occurs, a fited a diodetestlamp on the earth side of the injectors just outside the ecu and when I have this problem I'm not able to see any pulses from the ecu.

But the car will start if I put it in gear and release the clutch while rolling.

The car is cranking at 200-230rpm wich i belive should be sufficent.

Btw if I spray som starter spray in the airfilterbox while the problem is there the engine will pick up speed from the spray/gas and the ecu starts firing the injectors and the car starts.

It looks like the the ecu needs to se a lot more rpm when engine is warm.

I'm leaning towards a deffective ecu, remember the car is fine when it is cold.

BTW I noticed the ecu displays a 9ms fuel pulse whie cranking even when the ecu is not triggering the injectors.

Any help on this issue will be very much appreciated.

I have had a similar issue with a 3sgte, the reluctor CAS on Toyotas are getting of ages and when they get hot they can loose signal strength.

solution is to lower the voltage threshold to between 0.1-0.15v at 200 rpm I believe.

I did this and my car hasn't had an issue starting since, but im yet to get it to a track day and get it real hot.

but try this it cant hurt, ideally you should use an oscilloscope (I didn't as I don't have one) to determine the voltage and set the threshold to about 1/3 I believe.

Andre will correct me if I got something wrong?

Thanks, that is something I haven't tried yet, will give it a try tomorrow. I know that the distribuator that I'm using is an early type 4afe that is identical to the one on my 3sgte except from the housing off course.

But then again I doubt that it is going to help as the problem seems to be the injectors not firing even thoe the ecu reads both trigger and home while the problem is there.

But it cant hurt to to give it a try.

Thanks to Josh2703 the problem is now fixed.

After trying to alter the voltage threshold for both trigger and home fixed the problem, I tried lowering the values at cranking speeds when the car was warm and didn't want to start and guess what i started right up just like it should.

I tried to set it back to the old settings and the car wouldn't start again, but once I lowered the threshold the car started right up. I switched back and forth about 10 times just to make sure and every time I lowered the threshold everything was just fine.

Thanks a lot.

thank Andre, he told me!

just passing on information

Hey, do you by chance happen to have a good base map that could be referenced from your 7AFE? I've got a 7AFE wired to an Elite 1500. Haltech sent me a throttle position based map from a 4AGE but been trying to find others who've wired up a 7AFE

Do you realise the post is nearly 9 years old?

Well you responded to it

... and provided about as much help as you can expect from it ;-)

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