MPS, Rebuilding the MPS Options

[rjames]

ECUs do indeed go bad. You'll find plenty with injector corp rebuild stickers on them as proof. I went through 3 ECUs, inlcuding a NOS unit that accoriding to the shop owner had been sitting on the shelf forever (it looked brand new, too). I chased my tail because my car would go full rich intermittently.

Crossing my fingers that your issue is something as simple as a bad ecu.

[rjames]

duplicate post

[Superhawk996]

Late to the post but I think the suggestions made by the other guys are good ideas. Emery is spot on that you should be able to run it on a short burst of starting fluid but I’m thinking you may have already done that long ago. (IMG:style_emoticons/default/idea.gif)

If it were me I’d just allocate a little time to figure out why you’re MPS is having variability when you assemble it. The screws are m4 so be careful thinking more torque on them is the solution. They strip easily.

I’d make sure all is assembled in proper sequence and that the paper gasket and the big o-ring are lightly greased.

Might even smoke test (no!! not electrically) the other kind of smoke (IMG:style_emoticons/default/smoke.gif) if need be to figure out why the variability in the ability to hold vacuum.

Agree ECUs can go bad but pretty rare. @jeffbowlsby used to be able to test them for a fee I think - a few years back he did a group buy thing and I should have sent a couple to him. Not sure if he still provides that service.

The other thing you have in your favor is that you’re in LA so you’re in parts Mecca. Maybe a WTB ad in forums will turn up a local replacement. A spare isn’t a bad thing to have around if you can get one locally, cheap.

As far as swapping the 1.7L EcU and MPS - that is somewhat of a red herring. Mix and match is not very successful troubleshooting technique since you know it won’t be calibrated for a 2.0L. It won’t run good. And if it sort of runs, is it really answering any questions that help solve your problem and get you past CARB test? It won’t hurt but I don’t see it solving any problems you can’t without that swap. Just an opinion. (IMG:style_emoticons/default/confused24.gif)

[emerygt350]

If it does run it would make searching for or paying to have the ECU checked less of a gamble. Hate to buy an expensive part unless you know it needs it. That said, the fact the 73 just uses a 1.7 ECU makes me think most of the changes to the djet for the 2.0 are richness tuning and although he won't have the spacer in the mps, it won't be doing more than idling. Nothing besides the cht sensor changes in the engine so at most you would just be losing whatever improvements might have gone into the newer ECU, it should still run like a poorly tuned 73.

And even if you did do the ether before, I would give it a go again just to check and make sure, things get jostled.

And do figure out what's up with the leaks. It can only be a couple of things.