I have just fitted my 77 impala with a '89 MAF TPI, Painless harness, and new ECM, with 19LB injectors. All of my relays and sensors are new except for the MAF and the injectors. After burning my PROM with definition 6E minus VATS, I finally got the motor to run. The motor runs OK, but seems to have very little power. The check engine light is constantly on, and when I jumper the ALDL to get the codes, it stays on continuously. I can not read the codes, and it seems to me that there is some type of hardware problem I have to overcome before I can tune any further. Any suggestions on where I should look???

 

I am guessing you tried to reset all the codes???

 

I have tried to reset all of the codes, and that did not help. The engine does not seem to run very strong and it is my guess it is not coming out of closed loop mode, but I am stumped from here.

 

Check for the SES blink at key-on, engine-off. That will verify that the ECM is actually running from the PROM.

At key-on, engine-off the SES must turn on, blink off, then turn on solid. Without the blink-off the ECM is running in true limp mode.

RBob.

 

When I turn the key to on...the SES light illuminates, then as I turn it to crank...the light goes off until the key returns to the on position. When I turn the engine off, the SES light just goes out, no blink. Can I run in true limp mode if my vehicle has to have a custom PROM w/o VATS? When I take out the custom PROM and replace it with stock MemCal, engine just turns over w/o firing.
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I also read the thread "Service Engine light would not flashing. " from this January, seems like he had the same problem, but me ECM is new from parts store. My spare ECM does the same???

 

If the light doesn't blink when you turn the key one click past off, before you engage the starter, then your running in limp mode. Check the pins inside the ecm by removing the memcal. They may have gotten bent over while installing the new memcal. If none of the pins are bent then theres something wrong with the aftermarket memcal. The reason the stock memcal wont start the engine is because of vats turning the injectors off.

 

I have a spare MemCal and I will try that tomorrow see if it works. I hope that gets it!! Could it be that I burned and incorrectly made .bin to the chip? I have the software/burrner, and I did it myself. Would that cause the SES light to stay on?

 

Yes absolutely. But first we need more info on the modifications you made to the memcal and what type of burning hardware you used to burn the chip.

 

I used the 89vets.bin from www.diy-efi.org as I have a MAF setup. I reduced the injector size to 19LB/HR as I have small injectors. I then disabled the VATS. I am using TunerPro free v4.14.0379.The burner that I am using is from Moates.net and is a Burn1 Flash and Burn with a G1 Memory Adapter and a C2 SST 27SF512 chip. I am new to this, so this is my first burn, but I read up as much as I could. I didn't actually crack open the original memcal, yet used an adapter to bypass.

 

With the '89 MAF BIN and the 27SF512 chip you need to either quad stack the BIN or offset burn it to the top of the chip. Moates.net has the required buffer/chip offset values. Tuner Pro can be used to quad stack the BIN.

RBob.

 

RBob, I actually just read that myself. I was not aware of that previously. So am I to understand that all I need to do is set the value to 8000 hex for a 27SF512 chip replacing a 27C256? I have read that the 27C256 is the most common original factory chip. I just want to know if there is anything else I should expect, or may run into. Does the other chip burning items sound "within parameter"? Do you know the process for quad stacking within TunerPro? I definitely appreciate the help!!