I think i might have a bad ecm because my cars timing is all f***** up. How could i go about checking before spending the money?

 

What exactly is it doing? What kind of engine is it?

 

it is a 88 iroc, it just stoped running one day. i can get it to run if i advance it about a full plug but even then it does not run well at all. so i think it is the ecm but not sure?

 

oh by the way it is a 305 tpi, it is not fuel or spark problem have both. When timing is set right it does not even try to start. I have plenty of juice going to the coil, mod in the dist is also good. ???

 

Do you get a check engine light?

 

i have had a on off light for about a year now but was never able to tell what was the cause, so light is not helpfull. But i did not check weather it was on or off when it was running because i was under the hood. It also only runs with the the at 2000 rpm and above. I have also checked top dead center and that is good so it has not jumped time.

 

Have you checked to see if any codes are stored and if you get the normal code 12?
I assume you are checking the ignition timing with the timing connector disconnected.
This should take the computer out of the equation.

 

yes i have the comp disconnected, but i dont have a tech 1 to check for codes so i am not sure about any of that. Thats why i dont know what the light was on for in the first place.

 

Check for codes on the cheap like we did. I was actually very surprised to discover something so valuable could be had for free (Minus the price of the car of course).

On the right side of the drivers side under dash (hush) panel, you will see what appears to be a small cover of some sort, remove it. You will see a diagnostic terminal. Take a paperclip and insert it into the two top rightmost pins shorting them together. Put the key in the ignition and turn it to on but DON'T start the engine unless you wanna enter field test mode. Watch the check engine light, it will start flashing the error codes to you. The first code it flashes is 12. This is a normal handshake code telling you everything is hooked up right and the ECM is ready to begin. It will flash code 12 3 times then move on to the next code. When it is finished giving you all the codes, it will start all over again and flash code 12.

Good luck

 

i was able to get a tech 1 and i got the 12 code and also a 34 for the mass air flow being low but that was all. so i am not quite sure what that is telling me about the ecm. Now i guess all codes are kept in the ecm but can it tell me a code but still be faulty? If not where else can i be looking for the prob that i am haveing? Oh and thanks for the tip on the code checking always good to know! Any idea is a good idea at this point.

 

A bad MAF can cause a rough idle. Look here for some info on a 34.

http://www.chevythunder.com/fuel%20i...0pg%20a.htm#34

 

Its not that it has a rough idle it will not even try to start when dist is where it belongs. If i advance about 1/8 turn it will run but real bad. So i put a timing gun on it, mark is strait up, i then start retarding it and once i get close to 20 deg advanced the car dies. To restart the car i have to advance it once again and so i can't get close to where it sould run. so something is messing with my sparks timing and i don't know what it is, thats why i thought maybe ecm? The problem is much worse then just a MAF.