I have a 93 formula auto that I recently decided to make some upgrades on. Lt's cai tb mail order tune etc. In the process of all of that, the car died and wouldnt start. I changed the icm coil opti and already had new plugs/wires. Everything is new and still no spark. Come to find out I damaged my memcal during chip install. Found an exact match memcal to replace it and still nothing. All of my wiring harness appears to be in good shape no corrosion or apparent breaks. I dont know what else to try ....can my ecm be bad? Is there anyone who can refurbish them?

 

i dont know if this is much help but i was having a similar issue my problem was that my opti wasnt at tdc

 

What do you mean? The opti only installs one way.

OP, what sort of opti did you replace it with? In my personal experience, 50% of the parts store optis are complete duds to start with; the other 50% might take a couple thousand miles to take a dump. GM or MSD is the only way to go.

I guess it's possible whoever tuned it screwed up the PCM?? Who tuned it? Is there anyone around with a similar car that will let you try their stock PCM?

 

IIRC you can install the opti off by 180°

 

Not really 180 degrees but there's 3 holes on the late 94-97 vented optis but it's pretty obvious which one it is. The 92-94 spline drive opti is basically impossible to do wrong unless you force it on with a hammer lol. You can get the rotor 180 off though.

 

First replacemt opti was a delco....ive since swapped it for 2 other brnds with no different results . I have the notch on the rotor lined up and wires routed correrly I tried 180 deg just out of curosity. Solomon with lt1pcmtuning did the tune. Ive been in contact with him he said hes never had an issue. But I also had no speedo odometer my oil pressure was through the roof .At first if I put the stock tune back in it would start now it wont even do that.......thats kinda where I am at trying to find another 93 ecm

 

sorry I meant the rotor of the opti, not the complete unit

 

Does the starter work? Will it turn over?

 

Yes starter battery altenator tensioner belt ignition switch Icm coil opti plugs wires coolant temp air temp tps oil pressure map sensor almost every part on this car is new or been touched. I looked up the testing procedure on shbox about trying to test individual ignition parts. Ie high/low resolution how much volts I have on each wire etc but I dont have a meter or scanner to go any further myself. At this point I dont think its the opti but I could be wrong....is there a cam ot crank sensor that can be causing this or it has to be in the ecm? Anybody know of someone who can test or refurbish ecm's anybody have a 93 ecm I can borrow or buy to test if thats the problem....I cant find one anywhere

 

The opti is the cam position sensor

 

So I got fed up with the car and called a friend of mine borrowed a trailer and snuck it in the back door of a local gm dealer. They were able to pull codes etc and Come to find out they found a problem with the security system/vats. did I cause this by deleting the vats with my mail order tune? I dont have all the details yet picking the car up later today but at least she runs !!!

 

Ha! Somebody should have mentioned to look for the "security" light...no idea about the tuning question, although I had a similar issue last weekend when I replaced the PCM to my Regal GS with a zzperformance tuned PCM; it would not turn over.....I left the key in it and tried to reset the pass lock system; 15 minutes later it started up with no issues and has been fine ever since.