Been trying to get this sorted out for a couple of weeks now and it's getting pretty infuriating.
After replacing the faulty EGR position sensor, the engine now finally runs at initial 10* BTDC w/ spout disconnected. Previously, it needed a LOT of advance.
So it runs & idles pretty well in park, but once it gets warm/hot, I can't get it to move without bucking/stalling/knocking. It's ugly.
After clearing the codes and running the engine for a bit, I still get a Code 34 and 67. Like I said, I have replaced the EGR position sensor, and also the EGR solenoid, and I cleaned the EGR valve itself, and it seems to be in working order. (I applied mouth vacuum & it opens freely, also opened it with a screwdriver with engine running & could hear the difference). I get 5 volts at the EGR position sensor connector. I also get about a 5" vacuum reading at the EGR hose while revving it a bit.

After clearing the codes, It's still throwing trouble codes 34 (canister or EGR valve control circuit or EVP voltage high) and Code 67 (Neutral Drive Switch fault, switch circuit open/ A/C on during self-test) for the KOEO test and 34 for continuous.

I'm at a loss here. Any thoughts?

FWIW, I've also replaced the 2 coolant temp sensors since the one for the gauge was bad and I figured I'd replace them both and drain the radiator once.

 

I guess I should mention re: code 67 that the van starts in Park/neutral and doesn't start in gear, just like you'd expect. And the A/C hasn't worked since I've had the van, and I don't really care about that. And no, it wasn't switched on when I did the test.

 

Went to the salvage yard & gambled with a Z2D1 1993 F-150 2wd ECU with a 5.0, because I read somewhere (where, I don't recall) that an 88-94 with the same drivetrain should work.
Well, it runs about the same. Same symptoms when it gets warm & I try to drive. Only now, it spits out a plethora of fault codes that I can't make heads or tails of. I'm thinking this computer is not really compatible with my 89 E-150, and that I should just put the old computer back in & keep troubleshooting.
Help. This is getting expensive & frustrating. TIA. Subford? Anybody?

 

OK, I'm not sure anybody is following this, but I'm gonna go ahead & post a follow-up and hopefully someone other than myself can add some input.
I Swapped out the EGR valve with one off another van and sure enough, it got rid of the code 34. So at least there was some progress today.

But I'm still getting a code 67, despite the neutral safety switch operating fine. It starts in park and neutral but not in R or O,D,L.
Is there an easy way to trick the ECU into accepting the current switch or do I need to replace it?

By the way, it still runs like crap. I need to clear the remaining KOEO code so I can finally get on with a KOER test. How do I do this?

 

It's been along time done a self test on on my 94 f150, but I seem to remember that you need to shift out of park during the test as well as turning the AC on and off.

 

As far as being out of park, that's not right, as far as I've ever known & done it. But for these purposes putting it in neutral might not be a bad idea.
The A/C was switched off

 

Nope, that didn't work.

 

FYI, my Innova book says nothing about turning on/off the A/C or shifting in or out of park. I think the presumption is that it is in park. The only thing it does say about anything along those lines is to warm up the engine and to not depress throttle during this test.

 

OK, I replaced the neutral safety switch with the one from the other van. Starts in P & N, not in gear, reverse lights work in R, yet still I get a code 67.
What could be up? Is the switch even adjustable on an AOD? It doesn't seem to be.

 

Maybe that was for the engine on test? The only other thing I can think to try is to check the AC fuses or see if the PO ran a jumper power wire to the clutch to try to make it work.

 

Code 67 is only for the A/C in the KOER test, in the KOEO it's the neutral safety sw/PNP switch (park neutral position).
So frustrating. Thanks for the input though. I would have thought there would be more responses on this.

I did find a bad injector, and replaced it, but even though it idles a bit smoother, it still runs like crap and stalls out in drive