alconk

I just did the EBL ECM upgrade to my 82 but haven't tuned it yet. After putting the ECM back into the factory location I started the car and idles really good. Next morning I went out to start it again and now it won't start. The injectors squirt fuel but shut right back off and when doing so the car will start for a second. Could the fuel pump relay be bad or maybe I knocked it when putting the ECM back? And if it went bad would it even start for a second?

AL

usmilret

AL Try reinstalling the old ECM and see if it runs.

alconk

I swapped back the factory ECM and still won't start. Does the same thing. I have the fuel pump relay out and it has 5 terminals, not sure on how to test this. I took the cover off to see the coil and it all looks fine. It has alot of gooey stuff on the terminals though and looks like tar. That might be a factory corrosion coating?

alconk

I just swapped the air flapper relay for the fuel pump relay (same ones) and still does the same thing?? Could something be fried in the distributor?

gjohnson

Is the service engine light on? Check 4 codes. A bad oil pressure switch or connection will keep it from starting. Good luck keep us up-to-date

terry82

are you getting spark when you are cranking it?are the plugs wet?

alconk

Yes I'm getting spark and the plugs r slightly wet. The injectors fire for a second and it will start up but then the injectors shut back off . I have the factory service manual and read something in the distributor has to sense a signal or it will shut the fuel pump off. So far though I have not pin pointed information about my scenario in the manual.

BLUE1972

I'm not positive on your year, but it sounds like the oil pressure switch ( on some it's next to / behind the distributor ) If it senses no oil pressure it shuts off the engine / fuel pump.

JUST A GUESS..

terry82

IF the car wants to start ,I would turn over motor and pour a little gas down the tbs. if it runs the the problem is fuel.If its fuel, check to see if pump is getting power.if its not look into why.Check all your connections that you worked on .

alconk

Ok this is weird! Go out to the garage this morning turn the key and car starts right up?? I check for codes and shows faults pass. That is with the old ECM, now I'm going to try to switch back to the new one and see what happens.

alconk

I switched back to the new ECM and now I'm back at square one. Doing the same won't start. No CEL light and when checked the reader is saying try again miscommunication?? Switched back again to the old and still the same no start and no CEL. This is frustrating!

alconk

I also noticed when the key is turned into accessory position the tach needle stay put where normally it should drop to 0. The only thing I have done is switch ECMs so I wonder if I pulled on a wire somewhere in that area??

alconk

Well I'm following the service manual to trouble shoot and the first thing is to check for a CEL. After back probing pin 16 I have no power so it tells me to repair open or short to ground in CKT 439. Where can I find circuit 439? I have scanned the manual and doesn't tell me.

I also have a Powermaster III that will check for opens but have never used it so looks like I finally get a chance. I just need to know where that circuit is.

Ok I figured out the circuit # which refers to the pin # in the terminal block but I have no power going to the ECM fuse and still tracing wires but man this is frustrating. Anybody have any ideas where to check?

Buccaneer

Al, in the back of the book (pg 8A-87, sheet4) in the diagrams it shows all the circuits. CKT 439 goes from the white plug (ECM) pin 16 to ECM 10amp fuse on fuse box. That is the +12 v ignition switched signal. You may have an issue with corrosion at the box giving you the intermittent power or the ECM end at the plug. Good luck with the troubleshooting, you'll find it.

lionelhutz

I'm a little late, but I would check that the ignition switch is not having an issue and only providing power when you have the key in the crank position. So, you turn the key to crank and the engine fires so you let it back to run and the power cuts off and the engine dies.

The injectors firing says that the distributor is OK and that the ECM is getting the ignition reference pulses from the distributor, since it fires the injectors once for each ignition reference pulse.

The oil pressure switch shutting the engine down is a complete red herring. It'll even run without the oil pressure switch connected to the plug.

alconk

Ok I found that and have no power there. However if I take my Powerprobe and apply power on that pin by back probing I get my CEL comes on and the tach drops to 0 like it should. I tried starting the car with the Powerprobe but battery was going dead.

Also I have continuity on pin 12 (450) for ground but none for pin 13 (450). I tried taking a jumper from pin 12 to 13 while plugged into the ECM but still didn't start. Still trying while pulling my hair out.

alconk

Well that's just it I'm not getting power when the ignition is in the run position?? Could the ignition switch be causing all this mayhem? I don't see in the schematic where it runs through that switch. And better late than never!

Buccaneer

OK, so if you have no power at pin 16, but when you apply 12v to it things start to work...kind of. That would tell me it's on the fuse box end or somewhere in-between like maybe at the ESC where CKT 439 splits off to ECS 12v Ignition fused. Keep plugging at it.

alconk

Hurray I believe I have narrowed it down! . I pulled the cover off from underneath the steering column and the large black wiring harness mounted along side the steering tube has the same pink with blk stripe wire going to it. All I did was move it and heard the relay engage and saw the CEL come on and tach needle drop to 0. Turned the key and started right up. Then while it was running I moved that harness and it would cut the engine off then back on so I know the problem is there just got to find exactly where at.

Thank you lionelhutz for the idea of checking that area and to Buccaneer for helping me understand the schematic.

Not sure what that harness goes to yet but the car is running and it's pin pointed!

Buccaneer

Nice!! Take a look at page 8A-11, 8A-40 it may help a little more. See, you just have to keep after it and you'll find the issue sooner or later. Nice job...Now back to tuning.