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DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
So I have a 1226870 ecm and it was running like crud figured it was the injectors (it's been sitting for around 20 years and fuel pump went out). Anyway took it for a hour test drive before driving 5 hours home and the ecm burnt up. Opened it up and the middle and left quad drivers (I think could be wrong) are burnt to a crisp. Does anyone know what these correlate to and do I need to worry about wiring?
P.S. spent the weekend undoing hackoiry from both my father trying to remove the old school security and the security itself.
So I have a 1226870 ecm and it was running like crud figured it was the injectors (it's been sitting for around 20 years and fuel pump went out). Anyway took it for a hour test drive before driving 5 hours home and the ecm burnt up. Opened it up and the middle and left quad drivers (I think could be wrong) are burnt to a crisp. Does anyone know what these correlate to and do I need to worry about wiring?
P.S. spent the weekend undoing hackoiry from both my father trying to remove the old school security and the security itself.
Last edited by Makeitreal81; May 24, 2021 at 07:36 AM.
Reason: Pictures
May be. When it burns to the ground you may have wished you would have done away with all that rotten wiring. If it was a running car and this was a new issue Id be thinking differently but 20 yrs of mice chewing wires Id be getting it down to bare minimum wiring. Probably atleast look into a new harness altogether.
May be. When it burns to the ground you may have wished you would have done away with all that rotten wiring. If it was a running car and this was a new issue Id be thinking differently but 20 yrs of mice chewing wires Id be getting it down to bare minimum wiring. Probably atleast look into a new harness altogether.
No evidence of mice present unless you consider my dad and the alarm installers mice😂😂 Its funny cause my dad was 6'2". Now the vehicle has spent most of its time sitting in a nice garage so the majority of everything is good and intact. The fuel pump/tank rotted from the inside out gotta love ethanol.
I would but cars 5 hours from home and I just ordered a new ecm. I found someone else and it was suggested that it may be a bad solenoid so I'm going to ohm out all the solenoids and hope that it's one I can temp run without like evap or egr
You need to check every actuator that the ECM controls. Such as the TCC solenoid, fan relay, EGR solenoid, CCP solenoid and so on. Otherwise the next ECM will look the same.
Get the wiring diagram for the EFI/ECM, unplug the ECM, and measure the resistance of the actuators from the ECM harness end. Any that are lower then 22 ohms are bad. It may even be that some wiring is shorted hot to the q-driver.
You need to check every actuator that the ECM controls. Such as the TCC solenoid, fan relay, EGR solenoid, CCP solenoid and so on. Otherwise the next ECM will look the same.
Get the wiring diagram for the EFI/ECM, unplug the ECM, and measure the resistance of the actuators from the ECM harness end. Any that are lower then 22 ohms are bad. It may even be that some wiring is shorted hot to the q-driver.
RBob.
Thank you so much. This is what I was looking for, but I had found it by doing a more generalized search yesterday. So that's the plan and fingers crossed whatever it is it'll be able to live without so I can get it home. Tempted to tear apart my trans at home and pull the solenoids out of it so I have them ordered new injectors already and I can open the circuit for the fan if its needed.
So update I got it home!!! Although it did destroy the new ecm. Stupid egr solenoid almost caught on 🔥. So my question at this point is do I replace current ecm or do I upgrade or go to megasquirt? Is there anyway way to protect the ecm when a solenoid goes bad? I work on high end cars and it seems rediculious to me that a solenoid WILL take out an ecm. If I have to fuse every line or install bypass resistors I will.
Replace the three quad-drivers with newer ones. They are over-current protected. GM did this same thing after finding what you found. Recall that '85 was the first year for this style ECM.
The TI/Nat-Semi DS3668 is still available and is a direct pin compatible device.
If the PCB board is still OK you may be able to repair the two ECMs you have. Every now and then the bad q-driver will take out the chip that turns it on & off.
Replace the three quad-drivers with newer ones. They are over-current protected. GM did this same thing after finding what you found. Recall that '85 was the first year for this style ECM.
The TI/Nat-Semi DS3668 is still available and is a direct pin compatible device.
If the PCB board is still OK you may be able to repair the two ECMs you have. Every now and then the bad q-driver will take out the chip that turns it on & off.
RBob.
Thank you. That's so helpful. I'm not great with repairing microchips, but I can upgrade the ecu to a newer one and not be worried about it as much. I was wondering why I didn't have these issues with my old '87 and '89 tpi camaros I had when I was younger. They had other issue like rust, but the ecus worked good😁
