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Tue Apr 19, 2016 8:15 pm

Okay I seriously need help.
My 72 Squareback had dual carbs on it when I got it, but I'm a purist and love originality. So I put the original fuel injection back on. I got it running and it seems to run good. I set everything by the book. It starts up every time and idles perfect. But..... there's one issue I'm having with it that I can't figure out. Basically it acts like it has a rev limiter. It will idle all day perfectly but once you drive it down the road it'll do good until you get to a certain rpm then it'll start cutting in an out really bad. Like really bad to where even if I do full throttle it won't do any.
Today I put new injectors on it. I for sure thought it would be fine. But now it's running worse. I've tried different trigger contacts, tps, coils, and intake air temp sensor. Fuel pressure it at 28 psi. It definitely feels like an ignition problem to me. Timing is set by the book. Dwell is set. I'm starting to think something is wrong with the distributor itself.
If anyone has any ideas or has experienced something like this please tell me what's going on.
Thanks

Tue Apr 19, 2016 8:23 pm

Did it run like this with the twin carbs?

Are you using the same distributor?

Tue Apr 19, 2016 8:34 pm

No it didn't. It had the twin pdsit stock carbs with an 009 dist.

Tue Apr 19, 2016 8:50 pm

72squareguy wrote: No it didn't. It had the twin pdsit stock carbs with an 009 dist.

OK, then, verify that both distributor advances are working.

1972 had a D injection system with a dual vacuum distributor unless it's a late '72 California model with an E system and five prongs on the throttle switch and single vacuum.

Which system do you have?

Tue Apr 19, 2016 9:00 pm

I have the E system. 5 prong switch.

Tue Apr 19, 2016 9:03 pm

72squareguy wrote: I have the E system. 5 prong switch.

OK, can you verify that the ECU and MAP are correct E units also?

Do you have a single vacuum distributor?

Tue Apr 19, 2016 9:27 pm

Yes they are e components. And yes single vacuum. Distributor number is 311 905 205 AG

Tue Apr 19, 2016 9:37 pm

What is your FI wiring like?

Tue Apr 19, 2016 9:39 pm

72squareguy wrote: Yes they are e components. And yes single vacuum. Distributor number is 311 905 205 AG

OK, verify that both the mechanical and vacuum advances are working, please.

Tue Apr 19, 2016 10:07 pm

Okay and mechanic advance is working and dash pot is holding vacuum.

Tue Apr 19, 2016 10:08 pm

Wiring was kinda rough at first I had to clean lots of grounds.

Tue Apr 19, 2016 10:23 pm

The fifth terminal on the TPS is for full throttle enrichment. It's possible that this is not working.

Tue Apr 19, 2016 10:49 pm

The terminal on the switch itself or thru the harness?

Tue Apr 19, 2016 10:58 pm

72squareguy wrote: The terminal on the switch itself or thru the harness?

Either one is possible.

Tue Apr 19, 2016 11:10 pm

Okay. Can an out of adjustment MAP cause issues ? I know mine is supposed to have the black platinum cap on it but its gone. Someone might of screwed with it.

Tue Apr 19, 2016 11:27 pm

Wed Apr 20, 2016 8:57 am

72squareguy wrote: Okay. Can an out of adjustment MAP cause issues ? I know mine is supposed to have the black platinum cap on it but its gone. Someone might of screwed with it.

Sure it can. The plastic cover is often removed even if it has not been tampered with, so that's not conclusive. I would not further complicate things by trying to adjust it, at least until you have everything else set right (not just FI, but ignition as well).

Wed Apr 20, 2016 9:01 am

Do you have a vacuum port on the left side of the iad? It should be below the throttle cable. My 72 fastback does and that is where the distributor vacuum line connects. If I connect it where you have yours hooked up, it runs like crap. Your iad may be different...but it's worth a check.

Wed Apr 20, 2016 9:39 am

Yeah ktphil that's why I'm so lost on it now.

And fasty I found out about the other vacuum port the other day an I've already checked for it. It doesn't have that port on it so I'm good there.

Wed Apr 20, 2016 10:09 am

72squareguy wrote: Yeah ktphil that's why I'm so lost on it now.

And fasty I found out about the other vacuum port the other day an I've already checked for it. It doesn't have that port on it so I'm good there.

Yes, that other port was for '72 only with the D system. Yours is a 1973 E system that was also fitted to some late 1972 California cars.