Hi thridgen, just curious what and how I could tell if my ECM went bad or no longer works ? my 86 which won't start and I don't have power to anything and the "service engine" light won't come on, is this a sign ?

 

Check the fuel pump/ecm fuse. Ecm doesn’t sound powered up .

 

Is that the fuse located next to the battery? I changed it I also tested that power was running to the ECM but nothing was happening.

Second question is power suppost to be running to the ECM all the time, even with the key off ? I tested and it constantly has power, just curious

 

C16,B1 hot all the time from the fuse next to the battery. Accessory turn on is A6.
if those are good check grounds behind passengers side cylinder head.

 

Thanks I'll check them this morning and I'll get back to you

 

If nothing has power, no headlights, cranking, or whatever. Check the battery cables first. Then the fusible links that hang off the starter solenoid stud.

RBob.

 

Sorry I should have been more specific I have power cranking headlights blinkers, cabin lights, I don't have injector pulse, fuel pump won't come on, I checked the ground on the passenger side block and it has 12 volts when I use a multimeter. I'm testing everything now so let me know if you have any suggestions any info would help

I replaced every single fuse in the car just for ***** and giggles just to let you guys know

 

Also I have one more question if I do replace the ECM, I did an engine swap to change the 305 to a 350 and that's where most of my problem started, should I find an ECM for a 350 or will the 305 ECM run it just fine for the time being ?

 

Stock 350 with 22#hr auto or manual transmission ?
Btw I didn’t know, no power inside the car ? Fusiable link as rbob suggested if that’s the case.

 

Ok so from what I can tell I don't have cabin lights, like the instrument cluster lights don't come on when the headlights turn on. And I don't have over head lights. Where is the fuseable link? Is it coming off of the positive cable ? And how do I test it ? Thanks guys

Also I just replaced the starter on it if that's any help

 

And just a little more info, my instrument cluster is working like the fuel gadge and the battery gage
oh and it's an automatic transmission and it has a 350 in it, but it originally came with the stock 305.

 

The engine swap shouldn't cause the problem you're having unless something was not hooked up right. Did the power loss start with the swap or some time after? If the swap was for the same setup, TBI to TBI the old ECM should make it at least start and run.

 

It's a TPI, and it happened after, it hasn't ran in awhile, update though I moved some of the fusible links by the starter and bam I have a brake light on the dash which wasn't there before ! I noticed some say 6 and another 20 I think 🤔 any idea which one I need to change? And is it possible that if one those is bad the car won't start?

 

I tried starting the car I have all the cabin lights working now, but still no service engine light

 

Hey guys hopefully this isn't to much trouble to you guys I appreciate all the help ! Ok so I tested every pin on the ECM harness with the key on and I have the correct voltages, as well the grounds are reading. Any other suggestions or is it just a bad ECM at this point?

 

Does a5 of the ecm ground koeo ?
no fuel pump prime I’m guessing?

 

engine specifications? Injectors used ? Do you have to pass emissions if other than a stock engine?

 

It's pretty much just a crate 350 that rebuilt we beefed up the cam a little bit, that's about all I know about it. We used 22 lb fuel injectors, and yes I'm CA so everything would have to be smog legal, but I figured they wouldn't notice a 350 instead of the 305

It's an 86 camaro iroc z

 

You might leave well enough alone if it passes now. The only way I know is to do a custom tune and datalog to refine fueling. Can also use a wideband to monitor air fuel ratio to help get dialed in and pass emissions.

 

I appreciate the advice, just gotta get it started first. Its been 12 years since the last time it fired up so any ideas on what to check next ? Or just replace the ECM or could it be a PROM issue ?

 

I have a hypertech prom in the ECM is it possible the PROM is failing ?

 

If the ecm
isnt powering on it’s unlikely it’s the memcal. You would get a rapidly blinking light if failed more than likely.

 

Ok if I have power going to every pin that it should be from the engine harness to the ECM and I have no response from anything, is that a good sign it's the ECM ?

 

https://www.ebay.com/itm/14505575833...mis&media=COPY

this has a 87 350 non vats chip automatic transmission

 

Sweeeet just picked it up thanks for the heads up hopefully this fixes everything I'll keep you posted

 

Before I get and put it in, is there a way to tell its not a VATS system ? I just want to make sure I don't have any issues

 

The broadcast code on the chip says it doesn’t have vats. Vats started late 88 on f body

 

Gotcha but does the 86 corvette have a VATS system ?

 

Or is it just about the broadcast code on the chip?

 

yes it does

 

Ok so my question is since I don't have the VATS in my 86 camaro the computer will shut it down right? And if so do I need to.wire in resistors?

 

are you running a 86 Vette chip ? Your car is not equipped with vats so there’s no passkey module to bypass. If you’re trying to use a corvette memcal you won’t have injector pulse. There’s a few ways to bypass. Reprogramming or a hz modulator.

 

The computer I bought has the vette memcal, but if I run the stock camaro memcal am I all good to go?? No worry about VATS ??

 

if you bought the one I linked it’s not a Vette memcal it’s from
a 87 f body

 

Yes that's the one I bought, so it's just 87 vette ECM with a different memcal than stock ?

 

the 1227165 ecm was used in 86-89 tpi f and y body. The chip is from a 87 f body not y

 

Ok understood thanks for all the help ! I'll update you this weekend if I can get this pig started, or if I can't 😅