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.

[Ron914]

Well here is the long awaited update on my MPS/poor running problems I have been fighting.
MPS-I took it apart once again checked my notes for my caliber measurments. When I disassembled it I had 1.72mm for the stop screw and 5.46mm for my inner/outer screw assembly , I actually had two measurements for my inner/outer screw one for the center pin which helped me get back to where I was before I disassembled the MPS , my stop screw protruded by 1.72mm and the inner screw measured 5.46mm .
I did a vacuum test and although it not as good as I had it once my last test showed it held vacuum for 1 hour plus.
Next I tried the ECU and MPS that was loaned to me as a test and no difference at all and I would say ran a bit worse.
I tried spraying starter fluid as it died and. while I had someone turn it over for me and it did not want to ruin.
Now I decided to replace some ignition components. I replaced the coil with a new Bosch blue coil and changed out the points and condenser again . Set the points as closely to 0.016 as I could .
Rotated the motor as I checked for the TDC mark I found on the flywheel pulled the distributor cap ,rotor was pointing at the #1 plug slightly off the center mark on the dist. housing , I then static timed it and when done the center of the rotor lined up with the groove on dist. .
Everything seemed lined up so I tried to start it and it started . I have since driven it around ~ 17 miles.
I have discovered the oil temp still seems to me to be getting to hot and I still need to do a proper timing with the light ,I also need to get a bung welded into my muffler so I can dial in the MPS /CO readings .
For the purpose of this post I am satisfied and I will start a new post for the next issues I need help with.
Thank you ,
to all who have helped me on my journey I couldn't have done it without you .
@emerygt350 , @Superhawk996 ,@TJB/914, @ChrisFoley , @rjames , @JeffBowlsby and all the others I have missed .

[JeffBowlsby]

(IMG:style_emoticons/default/thumb3d.gif) We admire your persistence Ron. What a great feeling to succeed.

[Superhawk996]

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[emerygt350]

Yeah! If you are still at static timing that could cause your heat problems. Glad to hear things are progressing!

[rjames]

Congrats! Way to stick with it!
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[Ron914]

Yeah! If you are still at static timing that could cause your heat problems. Glad to hear things are progressing!

I agree , I will address timing and MPS tuning in the next post I will start soon .

[Ron914]

Congrats! Way to stick with it!
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Thanks for your help .

[Ron914]

(IMG:style_emoticons/default/smilie_pokal.gif) (IMG:style_emoticons/default/beerchug.gif)

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Thanks for your help , I have more questions for the next post I will start soon.

[Ron914]

(IMG:style_emoticons/default/thumb3d.gif) We admire your persistence Ron. What a great feeling to succeed.

Thanks for your help Jeff. If there is one thing I am persistent , I like to figure things out myself ( with everyone's help of course) , much more rewarding and I am learning a lot .