I was wondering...for those of you that have built a custom motor and therefore have a custom chip.... what would happen if you were out of town...say 500 miles from home...and the ecm/chip went bad. What would/could you do to get back home? (with obd II you could simply get the ecm reprogrammed or replace it, but with a custom chip what then?)

 

If the computer went bad, that's easy just pick up a new one at a junk yard, parts place, not a huge issue.

The PROM "chip" died yeah that would not be fun! That's why I NEVER EVER leave home without my laptop, charger, chip burner, and spare chip in the car. Now if you bought a tune and can't do it yourself, well, your screwed! Tow truck time

At the same time, there is "limp home mode" and my car will run on it without any chip in the ECU at all. It runs like CRAP since it's set up for stock injectors and what not, but it'll move the car. I'd hate to drive far on it though

 

Well, even with OBD-II, unless you have the BIN and the ability to re-flash it, it is no different then an OBD-I ECM. A dealer sure isn't going to be of help.

Best bet is to carry a spare ECM with a 'chip' that runs the engine decently. These ECMs today don't cost much. So just carry a spare. And the chip doesn't even need to be the latest one you programed (unless a major change has been made, like greatly increasing the injector flow rate).

RBob.

 

I've been driving TBI vehicles since the first one came out in a truck in 1987 and never had an ECM go bad. Heard of a few when these were new that went bad do do bad solder joints on boards. GM diagnostic TAP test! If they made it this long they are solid. Other then that it takes help from a human to make an ECM go bad, like wiring, welding, water etc...

I've yet to see a chip go bad? Even if you went to a parts store to get a new ECM it comes without a chip.

 

It happened to me. Well kind of. I ran a Prominator modified 7747 ECU. It uses a flash prom with 5 differing tunes held where I dont know. The eprom failed. I recall none of the 5 differing tunes worked. Yes the calpack functioned but barely allowed the car to run due to mods. Luckly I was not far from home. Limp mode is aptly named.