biker45

i am Backyard meckanic with an 83 944. 2 years (2000mi) ago before i got it on the road again after 2 years of boby work, i changed:

fuel filter, injectors, coil, cap, rotor, plugs, wires, air filter. Seemed to run fine. but i noticed a little rich exhaust smell and occasionally idle would fluctuate 800-1000-800. It failed emissions with high nox. i had o2 sensor and catalytic converter replaced and it passed. the idle problem remained sporadic.

in Virginia we need emissions every two years and I failed again with high nox.

did i mask the original problem and ruin the cat?

i have found one disconnected vac line and can hear a little air rushing in near/under the flex air boot but i cant isolate the leak even by spraying carb cleaner or wd 40 to try to hear a change in motor speed or noise pitch of the air flow.

i have checked out afs and tps for resist and voltages and both check ok.

one problem i did find is that i cant get a voltage reading from the leads to the idle stabilizer valve.

question is what to do to pass emissions and is my dme shot?

thanks

Shutemup

question for you,

What were your rpm's for the 15 and 25 mph test?

Also were the nox readings both high or only at one or the other?

I'm asking because mine failed VA emissions as well, fine at one speed but failed miserably on the other. I'm hoping it was just because my alternator went kaplut while on the test stand but I won't know for sure untill i get back in town

jd944

biker45 - I have just started to experience an idle problem that sounds similar to yours. My car will idle lousy at about 700-750 rpm and it feels like its loading up. It will do this for a while and then just start running and idling great at about 900 rpm. I have suspected the o2 sensor and the idle stabilizer but I have not had a chance to look at it yet. I hope to this weekend. I'll post if I find anything.

botchup

You guys are having the same problem I had. I also when throught all the scenarios, spoke to a couple of the guys at the club (Porsche) and they all agreed that it sounds like a typical 944 alternator problem.. I took it to my friendly German Autoelec named ... what was his name? Hans maybe, anyways, he took the alternator out and benched it.. it needed a refurb.

The car is 100% better now.. apparently if the voltage drops the car does what youre discribing.. take it out get it refurbed.. not too costly. It'll idle sweet! Avoid the runaround.

Shutemup

I know my alternator is bad, just haven't been home to fix it.