Narrowed it down

[tommey66]

I am working with a 1987 iroc tpi 350 motor, wiring harness and the 1227165 computer. Went to fire it up today and it just cranks, verified there is good spark at the plugs, verified there is 45psi in the fuel rail. Noid light will not light with all injectors unplugged. Verified there is pulse coming out of distributor and into computer, No ground coming out. All grounds were verified good, so im pretty sure that computer is fried. Can I take my memcal out of my computer and put it in another 1227165 computer, or are the injectors driven by the memcal? Also can I use any of the 1227165 computers? Thanks for the help.

[tommey66]

can anybody read this? on my computer it just shows up as a complete black back ground with a couple words in white letters

[dave w]

can anybody read this? on my computer it just shows up as a complete black back ground with a couple words in white letters

I don't know what happened with the text color. I changed the color.

To answer your questions: The memcal you have can be used in any 1227165 ECM. The injector drivers are in the computer, not in the memcal.
dave w

[tommey66]

Not to be a pain in the arse, but, are the injector drivers for ground in the memcal or computer itself?

[buddrow]

As Dave W stated the grounds are hardware in the ecm itself not the memcal. The memcal holds calibration files. Do you have the chip in your key? I have run into many a vehicle no-start condition traced back to a broken signal wire from the chip to the pk module.

[tommey66]

If im not mistaken 1987 didnt have VATS. And honestly, I would be kinda screwed if I had to figure that all out as this motor, ecm and wiring harness are installed in a 1993 gmc k1500.

[buddrow]

wd2.jpgDo you have any way to view data from the ecm? Do you have any history on the donor vehicle ecm,harness, etc..? Hard to tell for sure. Looked at the wiring diagram for the '165 and it does indeed have vats input. Check out this pic...Pin B6 is vats input so you're going to have to overcome this in either the bin change or grab a 5k pot and start turning and testing until it starts.

[tommey66]

Dont know where intake setup, harness and ecm originated from, was told from an 87 camaro. Motor is a 400 sb with vortec heads and some other work done to the insides, dyno sheet says 468hp/ 453tq. The motor was just pulled from a 1990 chevy k1500, was running and driving, just swapped for a 496 stroker. Nothing was cut, was a complete take out. I have no wire going into B6

[dave w]

If im not mistaken 1987 didnt have VATS. And honestly, I would be kinda screwed if I had to figure that all out as this motor, ecm and wiring harness are installed in a 1993 gmc k1500.

If I wanted TPI in my 93 K1500 (5.7 liter / 4L60E), I would upgrade the original PCM (computer with red / blue connectors) to Port Fuel Injection mode. Some solder spliced wires, a simple solder modification to the PCM main board and memcal would make a conversion to TPI much easier. Not many people know about the Port Fuel Injection modification, so the usual plan to convert to TPI is use a TPI computer and wiring harness. See attached .zip file on how to convert to a PCM for Port Fuel Injection.

Given the circumstances your K1500 is in now, I would recommend purchasing these few items from Moates.net that allow you the ability to reprogram the PROM. Sure, there is a learning curve. Were here to help.

http://www.moates.net/burn2-chip-pro....html?cPath=94

http://www.moates.net/c2-sst-27sf512....html?cPath=26

http://www.moates.net/g1-memory-adap....html?cPath=64

dave w

[Six_Shooter]

wd2.jpgDo you have any way to view data from the ecm? Do you have any history on the donor vehicle ecm,harness, etc..? Hard to tell for sure. Looked at the wiring diagram for the '165 and it does indeed have vats input. Check out this pic...Pin B6 is vats input so you're going to have to overcome this in either the bin change or grab a 5k pot and start turning and testing until it starts.

A 5k potentiometer will have no effect trying to get around VATS. The VATS signal to the ECM itself is a square wave 50% signal at 50 Hz, not an analog voltage.

Besides that, it sounds like this truck was running previously, and unless the OP can verify 100% that the truck was fitted with a way to bypass the VATS externally we have assume that the EPROM has been programmed for no VATS.

If nothing has changed, where it was running then shut off and then won't run again, I would look at the ICM first. I have seen a few where there was spark generated, but no DRP signal to the ECM. The ECM as a failure would be one of my last things to look at, since they rarely ever actually fail, at least to the point where LHM is also not functioning. How did you verify the signal between ICM and ECM?

There should be no reason whatsoever to grab a programmer and start throwing software solutions at what sounds like a hardware problem. Software never goes bad or wears out (just gets outdated), so when something randomly fails, there is a hardware issue that needs to be found.

[EagleMark]

I am working with a 1987 iroc tpi 350 motor, wiring harness and the 1227165 computer. Went to fire it up today and it just cranks, verified there is good spark at the plugs, verified there is 45psi in the fuel rail. Noid light will not light with all injectors unplugged. Verified there is pulse coming out of distributor and into computer, No ground coming out. All grounds were verified good, so im pretty sure that computer is fried. Can I take my memcal out of my computer and put it in another 1227165 computer, or are the injectors driven by the memcal? Also can I use any of the 1227165 computers? Thanks for the help.

Is there power to injectors?

[tommey66]

Thanks for all the input, figured it out, had power going to one side of injector plugs not the other. Started probing around the ecm connectors with a test light and found no power going to the ecm, fixed power source, truck fired right up. Yes this combo was in a truck a couple months ago and was running, I am assuming with the work thats been done to the motor that the chip has been tweeked.