Hey all
here's what I have:

1991 chevy work truck 1/2 T, 4x4, with 4.3, tbi 5 speed manual

At some point in time, the Control Module was fried, I pulled it, and there where numerous chips fried and baked, some pieces where bouncing around in the housing. I replaced the cm with a like module, a 16144288, removed the eeprom and installed the old one.

New battery installed, attempt to start, she winds over real good, but no fire.
Fuel pump, fuel filter replaced, fuel pressure has not been checked.
Upon attempting to start,she spins over good, no start, starting fluid sprayed into intake, she starts, but will not idle, she's doing about 2200-2500 RPMs, and will not take throttle, it bogs down and acts like it wants to die, ease off throttle and she recovers. Key turned to OFF, engine dies, on restart, no start, unless starting fluid applied, same as above, with regards to idle speed.
ALDL jumpered, it shows code 14/15, coolant temp sensor problem, R&R coolant temp sensor, same as before, and same error code, the control module was disco'd from power for approx 10-15 min, no change.

Some additional info:
this truck is used as a snowplowing truck, heavy duty useage in the past, but not so much the past couple years.
it has sat for 1 1/2 -2 years before this was attempted.
It was running fine before this

I would appreciate any info as to how/what I need/should look at.
Thank you
jerry
aka akjerry
bluestrkchain@yahoo.com

 

Are you getting any fuel out of the injectors? Is the check engine / service engine light coming on and going off when the key is turned on? Does the fuel pump run for a few seconds when the key is turned on? If the ECM was fried it may have damaged other sensors. Are you sure the original chip (eprom) is good. Just a few ideas. Keep us posted.

 

Yes, fuel is coming out of the injectors.
SES lite, with the eeprom from the replacement cm the lite comes on when the key is turned on, and goes off when the engine starts, with the original eeprom, the light is flashing, very rapid, and throws code 14/15, coolant sensor problem, R&R coolant sensor, no change, Fuel pump runs for a couple seconds then shuts off. Also temp gauge inop. If I ground out the temp gauge wire, the guage will move.
thank you
jerry

 

Ok you are definitely on the right track. When you replaced the coolant sensor does the SES light come on and turn off now? I would check fuel pressure which is a pain on these - you will need an adapter that replaces the fuel filter and has a schrader valve on it to hook the gauge to. If it will start when you spray starter fluid that tells you there is definitely a fuel issue. It could also be the fuel pressure regulator. I would start by checking the fuel pressure, if that checks than I would look into the regulator or the injectors themselves. How does the spray coming out of the injectors look? You say it will not respond to throttle once you get it started, but will idle. Sounds like you have a fuel starvation situation. The spray out of the injectors should be strong cone shaped. If all that checks than you might have a sensor (possibly TPS) that has gone bad.

 

ses lite on, then off on engine crank, but still throws code 14/15.
can't really say that I see a spray pattern from the injectors,with the engine running but can see fuel hitting the butterflies, with the key in on position, and engine not running, should there be fuel sprayed into throttle body when the linkage is operated?
thanks
jerry

 

If it isn't running it won't spray anything.

 

ok, I'm building an interface, aldl to computer, that will allow real time troubleshooting.
will let you know how it goes
thanks
jerry

 

update, this morning on starting the truck, she fired up with no starting fluid, a bit hard to start, but it did start. took a chance and drove down the block a short distance, lots of black smoke out the exhaust, but it seems to have plenty of power and a bit boggy, it did clear up when I got home.The high idle problem is/was still present, I had previously replaced the coolant temp sensor, and on some advice, disconnected the wires to the sensor, with engine running, the RPM decreased and again increased when the connector was reattached,so there is still a problem there, not sure if I should replace the sensor again or replace the connector.
still working on the aldl to computer cable.
thanks
jerry

 

BOY, do I feel dumb!!
In my first post, I stated that this was a 1991, WRONG.
Looking at the VIN plate, I see, manufactured in 1992, go get insurance card, it says 1993, do a VIN check, and it's a 1993.
Man I hate going back to parts stores and admitting "I" made a mistake, let alone declaring it here.
I apologize for the mistake.
I'll try and be more careful in the future.
thank you
jerry

 

Don't feel bad I wet to get my tune up parts the other day for my 1995 truck and had my 1997 Suburban on my mind. I got half way home and realized that I had ordered all the parts for a 1997 Truck. I felt real stupid because the parts guy told me Vortec and I say no it's the last year of the TBI and he kind of looked at me crazy. I went back with my tail between my legs. He loved it because I always rub it in his face when he is wrong.

So did you get it running right?