hey guys, still working out some bugs, would a code 21 or 22 (coolent temp sensor - knock sensor) cause a no start condition? if so does it just cut the spark?

wont stop the car from starting altogether, but the coolant temp prob may make it very difficult.

I have had a coolant temp sensor malfunction (OK-it was unplugged) cause a no-start condition on my car before (SPFI system) - I think it could do the same for the turbo - don't know about the knock sensor - try cleaning the sensor and wiring harness contacts before replacing them

the sensors are good, i probably just wired them wrong. so im assuming the ecu sees it as not there at all. there will still be spark though correct?

the sensors are good, i probably just wired them wrong. so im assuming the ecu sees it as not there at all. there will still be spark though correct?

 

Correct, unless something else is wrong.

allrighty well i go to wait till my buddy gets here so he can tell me if shes sparking!, thanks for the help guys im hoping its just the 2 sensors. thats all the ecu is telling me so fingers are crossed!

Check the minus side of the coil with a test light while you crank the engine. You should see a pulsing light. If the light is on and not pulsing then there is a problem with the pick up loop in the distributor. If the light is not on at all then you need to see why no power is getting to the coil. Check the positive side and if there is power there, then the coil is open.

well i have no spark, so i believe there is a problem with the distributer/crank angle sensor wiring. i know i have the coil and igniter wired right, the coil has power. so the distributer must not be gettign the signal to the ecu/coil. any thoughts. its an 87 mpfi hot wire style engine (optical dizzy)

its an 87 mpfi hot wire style engine (optical dizzy)

Hey Dneu----This is useful to know.

I would pull the battery power to trash the codes after making sure sensor terminals are all clean. After two minutes reconnect battery and then try to restart engine. Then recheck codes. Code 11 will indicate a disty problem.

ive done that and it wont throw a code 11 at me, im all confused now. lol. well i will double check the wiring on the ditsy and then check and see if the ecu is throwing an voltage at the igniter for the coil

well as far as i can tell the disty is wired correctly, red power / black referance / white position / green ground so if that is correct then ecu pin 37 should be firing to the coil/igniter correct? is there anything else thats needed to be hooked up to make it spark!!

Have you checked for coil firing with the test light as above? If not, i would try that to rule out a bad coil.

 

Has this engine been retrofitted?

If so, are you sure the ecu is getting power when the ignition is in the 'start' position?

It really doesn't make sense that the ecu wouldn't give a code 11 if the distributor was at fault, thats why i suspect it may be an ecu or coil issue.

sounds like your forgot about the ignition

amplifier

 

Many posts on the subject

 

it is mounted on the bracket that holds the coil

 

directly under it.

 

The impulse signal from the ECU is too small

and must be amplified to fire the coil

just an idea.. ignition fuse.. this happened to my roomate this morning.. he changed this coil and disty and it still wouldnt run.. I popped the fuse in, boom worked fine

well i have the ignition amp hooked up, ive checked the coil, its getting power but is not firing. i will check and see if the amp is getting signal from the ecu. the ecu appears to be functioning as far as i can tell. im really stumped on this!

The signal is generated by the pickup in the distributor, not the ECU. If you have the transistor also make sure it is grounded well and works.

Glen is correct about the ground, the bracket must be connected to the negitive side of the bat.

 

but

the ECU does send the signal to the amp

 

The ECU gets it's signal from the

crank angle sensor (cas) in the dist.

 

If you hear the injectors clicking the cas

is talking to the ECU

Thanks for keeping me straight Skip. I was thinking the disty was tied direct to the coil like a set of points would be. The memory is going.

Hey dneu----If the coil integrity checks out O.K., i.e. primary- .84 to 1.02 ohms, secondary- 8000 to 12000 ohms, and primary to case- >10 megaohms, then I'd suspect the igniter transistor also.

 

Interesting you mention double checking wiring. Is this necessary because it's a retrofitted engine with an earlier years ECU?

if you haven't found it already - http://www.finleyweb.net/default.asp?id=142

the manual is not complete for turbo cars, but the CAS system is identical for 87+ MPFI turbo and non-turbo - in fact my current CAS is off a turbo car - this should help your troubleshooting because it covers how to test the CAS

 

unless you KNOW the computer is good, I would not rule it out either - I had two bad ones that would display an error code for the CAS, when it was really working fine, and not give me an ignition pulse

 

Good Luck!!!

ok guys just got back from work and checked a few things out, i followed the fsm and determined that the CAS/disty is wired correctly and working properly, however the is no spark. i checked the voltage on pin 37 and found it to be constant, i can turb over the engine and it wont change? any ideas?

First, make sure fuse #5 is good and there is voltage to it. If that is ok then I would check to see that the wire from the CAS to the ECU is ok and that the pulses are getting to the ECU. An O-scope would be nice to look at the pulses with though you may be able to look at them with a digital voltmeter with the AC volts selected.

my FSM says it's fuse number 11 that feeds power to the coil??

 

the power transistor (ignition amplifier) is connected to pins 37 and 43

 

wonder of an open or shorted power transistor would cause a no pulse situation

My manual does show fuse #11 to the coil also Skip. Fuse #5 provides power to the ECU through the ignition relay. Since there are codes being sent out the fuse may be ok but I just wanted to make sure that was ok. I spent a lot of time on a problem once where engine wouldn't fire due to lack of spark and it was because the fuse was not in place.

 

For the transistor, it could be open and have a voltage present that he saw but didn't say how much. If the device was shorted, then he would not have seen a voltage and would be at ground potential.

right you are Glen about the short

 

on the fuse issue he said the CAS was working

 

I have to assume the ECU has power.

 

Maybe time for him to go fishing in the bay of E

 

for a FSM

 

Or download the Finley web copy

 

 

 

 

Why has he never mentioned the ig amp?