bronto

This is the first injected car I've had that I actually work on, and I'm not sure what to make of it. If it were carbureted, I would say that the choke is stuck. What do I look for on my '79? After it's up to operating temp, it's still not perfect but is barely noticeable.

RicerSchnitzzle

Does it start right up.

First thought is always temp sensor that controls start up valve. If it starts fine, then it could be the warm up regulator or vacuum line leak.

bronto

Yes, starts right up but idles rough. Has trouble getting above idle for a few seconds, then it settles down. But it really doesn't like revving until it's at op temp. I don't think it's a vacuum leak, since it's a cold/hot issue. Unless the leak effects cold operation controls only.

devilinblack

Do the 79's have the aux air valve? I removed mine for troubleshooting and blocked the lines and the car started and ran, but idled like hell for the first few minutes.

bronto

No idea. Anybody?

Ben Allison

could be a partially clogged injector that's not opening properly at the lower system fuel pressure when the engine is cold. Rapping each injector with the end of a wrench will often dislodge any accumulate dirt in the injector.

Might not be the problem, but it's an easy one to check and cheap to fix.

devilinblack

According to wikipedia and the PET you have the same Auxiliary Air Regulator as my 78. There's a bunch of good articles on rebuilding but the testing is pretty simple. Remove it, place it in the fridge/freezer and verify that it's opening. Remove from the freezer and connect 12v to it and verify that it closes, I think I read 10 minutes is the allowed amount of time to completely close, but mine took just over 3.

It's a pretty quick and easy thing to check, so I'd start there.

bronto

I looked in Pet and it seems inconclusive as to part number. From the schematic in PET, I at least know what they are supposed to look like, and yes, there is something like that near the front on the plenum, mounted to the block or some part of the cooling system. It's got a big arrow on the top point forwards.

I'm a bit confused about which is the one i've got. What's in PET seems to be for an '82(?). 928intl isn't clear on model year. Pelican parts doesn't list anything for 78-79, '80 and up is NLA:
http://www.pelicanparts.com/catalog/...FULint_pg1.htm
The part listed in PET does not say it's for a 928:
http://www.pelicanparts.com/cgi-bin/...606-102-00-OEM

Looking for that rebuild thread now.

bronto

I found this Scott Mohr thread:
https://rennlist.com/forums/928-foru...de-an-aav.html

So it seems you have to drill out the rivets to test it? Certainly to "rebuild" it, although the rebuild seems to be more like monkeying with it until it works...

Looking at the dissembled unit images, this thing looks really simple. Why do they cost so much? It also seems that a functioning used one might be as good as a new one. Or at least a functioning used one might be better than a "rebuilt" one. ?

jpitman2

As devilinblack said, open up the AAV and fix it. My 83 Kjet was like this for a long time, but after opening the AAV and adjusting so that it openend more when COLD,all is good now. Its really quite simple inside - as above, put in in freezer, bend the arm the return spring is on until its 80-90% open,check that its close to fully closed when back to ambient, or after a minute or two with +12V on it, and close it up. IIRC I used M6 bolts to close it up again - the thing will need to be air tight at the joining face. Very cold starts now I get an idle at 1100-1200rpm, and no more stalling out, even though that was rare.
jp 83 Euro S AT 52k

devilinblack

I didn't disassemble or drill anything out to do the tests I described. Yes, you'd have to drill them out to adjust and refurbish it.

Mine wasn't working, but was the opposite of your problem, the valve was opening but was taking forever to close, it turned out to be the power going to it, once I replaced the plug it was fine.

Dennis Wilson

Try unplugging the cold start valve after initial startup. It is supposed to shut off after the first few seconds but if you have a bad thermotime switch, it will overly richen the engine when cold or hot.

Dennis

bronto

It turns out it was the warm up regulator. Runs wonderful now.

jpitman2

And what was done to the WUR to fix the issue please? Mostly these suffer from a build up of fine crud on the gauze filters....some peopleremove them altogether.
jp 83 Euro S AT 52k

Catfood

These cars always get gummed up when they don't run for awhile. Enjoy!