Now that I have you attention my car died out of knowere and would not start.I noticed that when I turned the ign on the SES light did not come on.So I went home and grabbed the ECM out of my 91 4.3 sonoma,plugged it in reset the batt and she fired right up.It seems to run ok maybe a bit stubbly but that could be from not full tightening the batt cables down.Is it ok to use until I located a proper replacement?

 

I did a search and s10 owners say the ecms are the same and that my car will run lean (which it is) and that I can switch the proms from my car to the 4.3 ecm.can anyone verify this?

 

They're wrong, lol. So wrong it isn't even funny, like ah... hmm... it's just easier if I call them stupid .
The chips don't interchange and your 91 4.3 doesn't use the same ecm as your camaro. If it did it would have the same number on the outside. Your ecm is a 8746, this means it's different, different as in the ROM code that's built in. Basically speaking if you put the a chip in from a different ecm number it won't run! Code is stored in the ecm (rom) and they look up different locations in the chip (eprom).
The ecm itself uses very similar inputs as your s10, this is why it runs. I think you had better get a replacement ecm before you blow up (apart) your engine. ECMs are a lot cheaper than the engines... at least where I'm from they are. Not to mention the time it takes to actually replace....

 

Could you send me the link that has an s10 owner telling you they are the same and that it will run lean.

 

Join Date: Dec 2002
Posts: 17
Post Per Day: 0.02
Location: south jersey

Trader Rating: (0)

User is: OffLine

Hi,Up to 1992 s10 4.3L V6s USE a 700r4 trany,If you use a 305 or a350 Chev. The ECMs are the same,but you will need a PROM chip from a 1/2 ton P-U the same year as your s10, with the same options.For 1993 to 1994 the 4.3L uses a 4L60E tranyThe 93 or 94 ECM#16196395 or 16197427 are the same for 305 or 350 chev but you will need a 1994 1/2 ton p-u PROM same options this makes everything work. (DTNLUB) TOM

http://www.s10forum.com/forum/showth...&highlight=ecm



My engine will blow up? can I used a ecm from a fullsize LO3 pickup?

 

To my understanding truck ECM's are also non compatable without a lot of work. Just get one out of an LO3 car in a junk yard. There are millions of them out there. By blow up he means irreversable damage due to improper fuel and spark management. Even a new ECM at autozone is like $70. Why risk it.

 

That guy isn't talking about the 8746, he's talking about the 7747 which came in the trucks. A 7747 will plug right in, you'd still be shooting yourself in the foot.
Your engine won't blow up, but it could be damaged. Just get an 8746 from a full size b-body (caprice) or 89-92 TBI f-body. You could also get an ecm from an 88 but why bother with the vats issue, just get the right ecm.

 

The real issue with using a V6 ecm is that the ecm will register the rpms as higher then they actually are with a V8 since there will be 4 reference pulses rather then 3 per revolution. The fueling and spark will also be off but maybe not by too much.

Just get another 8746...

 

Update I plugged in my old ECM and boom it now works.But before the SES light would not come nor would the car start.I drove it all day and it ran great.Maybe I should buy a backup?

 

I certainly would.

 

When you reset the batt, did you also happen to clean corrosion off the batt and/or off batt cables? I know mine is really picky about clean connections. If you did clean corrosion off, that may have been your problem from the start.

 

Gnarley...if you want to test another one out....to help diagnose...I live in the "sauga...so just south of you....I have no problems doing so.

Dave