julesf

Hi Guy's

My car has been running great since forged rebuild by Advanced automotive, plug ;-) I ran the car in as instructed and have covered about 2000 Miles in all.

The other day driving home a little misfire developed. When I got home I noticed that the car would not idle, and if I held the revs at 2K ish fast idle the miss was still there. My car has early Simtek and I have the programming kit so put the lap top on the car and found that all readings where normal and as expected from all sensors etc. I also have wide band which also read a sensible AFR during my Testing. Over a day or so of testing, the fault got better and then disappeared all together with no miss at all, even on max boost.

Sadly that evening the misfire came back again, first a little and then the car would not idle again with missing at fast idle etc.

This morning I went to start the car and it's dead, it cranks but wont start.
It does try and fire, but only a couple of times when you let go of the key, while cranking there is no firing at all, the car smells of petrol so is injecting.

Again I fitted the lap top, all readings normal, the crank and cam sensor can be seen pulsing the cylinder numbers, the tacho shows 170 RPM cranking speed and the sensors all show as expected.

So far I have checked.

Coil pack voltage (normal)
injector voltage(normal)
Ignitor earth (present)
Fuel pressure (normal)

I have also changed

Ignitor
crank sensor
cam sensor
MAP sensor

Although lap top showed good I thought I would change the parts anyway.

I have also checked for Cam belt slipped, timing normal. Again this was just a precaution and was not expected as belt and tensioners are all new.

I dont have an oscilloscope but have tried measuring the pulse fron the ECU with a high impediance multimeter and I am not sure if I am getting a pulse from the ECU, I dont think so.

Could this be a faulty Simtek ECU.

Does anyone know if the ECU could cause this fault, I did have one injector
driver go faulty some time ago, and this was a common problem with Simtek as there was a faulty batch of drivers, though this is all sorted now and they don't fail like this any longer apparently.

I am going to try a stock ECU to see if it will fire on that, if it does it must be the ECU. But there is no support as such, no one that you can contact for advice, and how long would it take to get a repair done.

Any thoughts from anyone who may be able to suggest some further tests or may know the architecture of the Simtek ignitor trigger circuit.

Thanks guys,