An 88 prom/ECM won't work on a 89 correctly on startup cuz of the no cold start, correct?

My 89 runs pretty good, but is a bitch to crank. Im using a 88 ECM.

-- Joe

 

ECM's are the same, but you're correct, the '88 has the Cold Start Valve to add fuel, the EPROM in the '89 does not. The '89 EPROM adds fuel via injectors at cold starts. Could be the '88 EPROM is not giving enough fuel at startup.

But, many have mentioned with thier '86-'88's they have removed the CSV and still use the stock EPROMs, and don't have starting issues...maybe your problem lays somewhere else?

 

If you have an 89, you can use the 88 ECM but not the 88 Memcal (as mentioned by Mike). My suggestion would be to purchase a 1989 Memcal, if you aren't using it already.

 

Hey,

Thanks for the response.. Once its started it runs ok. I've got a weird floating idle tho. Sometimes it idles around 700rms. Other times it bounces way up to 1700..

I have a SLP camshaft. I think its like 212/214. 355cid, with sportsman II heads..

My ECM unfortunately is from an 88 cuz I don't have an 89 ECM. I'm wondering if the prom is just freaked.

I'm also wondering if I should just buy a prom burner and start messing with images. I havn't burned computer proms in years (wasnt for cars) but I think I could get the hang of it for cars.

- Joe

 

The memcal is part of the prom or is the prom or?

The whole ECM came out of a 350 formula, but 88..

Im gonna start reading up on burning proms.

-- Joe

 

Glenn is right, you need a chip from an 89. Without the cold start hooked up, all the cars I have checked have extended cranking during startup to get the car running.

 

Thanks Max.

I think I'm gonna get involved with burning proms. Figure it'll cost me like 250-300.00 or supplies. Then I can start tinkering with things.. If I buy proms they'll cost 100-150.00 a wack anyway so might as well make my own.

-- Joe

 

That is why I got into eprom burning. In fact, I decided to start with my basically stock engine so I had a "safety", plus it would allow me to do more analysis of how the various constants and tables affect the stock settings. It's a heck of a lot easier to start burning proms before I REALLY need it as I am not fighting tuning issues while I am also learning. Now that I am very comfortable at burning proms myself, I am now debating what I want to do to my engine next.

 

Hey Man,

So what direction did you go? I'm looking at the pocket programmer, an tunercat.. What do blanks cost for 85-89 ecms??

-- Joe