HELP!!!!!!

[Jeremy G]

OK here's the deal, I've got an idle of about 2200rpm when warm. I know what you're going to say, "vacuum leaks." I have done everything I know and everything I've been told and the problem only gets worse. Here's what I've done: All new hoses w/ clamps on all of them. New intake boots(w/clamps), gaskets and injector seals. New MPS. AA valve and PCV valve and gasket underneath are all fine. New gasket under throttle body. What else could be a source for a leak???????
I place my hand over throttle body and it goes down below 400. So answer this question: Can <400rpm worth of air with the throttle valve totally closed off produce an idle that is 1300rpm too high with freeflowing throttle? I can't understand how a leak could produce 400 rpm at maximum resistance and at next to no resistance(idle) the same leak produces an idle that is 1300rpm too fast. So if anyone thinks that a vacuum leak is my only problem, you'll have to explain yourself. BTW I got a 73 2.0 D-jet engine w/crane 700 electronics.
Please help. If I can't solve this soon, there will be another 2.0 on the market. I'm frustrated more then words can discribe.
TIA jeremy

[Steve Frankiewich]

Most of my experience is with the L-jet on the 1.8, but I found that the plenum which connects the air filter assembly to the throttle valve had age-hardened and developed cracks. The air flow meter on the 1.8 is upstream of these leaks and this affected how the car ran. I sealed the cracks with high temperature silicon seal. Might not apply to your D-jet.

[This message has been edited by Steve Frankiewich (edited 05-22-2000).]

[willisb914]

Jeremy,

Are you sure that your timing is set correct? Have you checked the hard plastic "blocks" at the intakes for leaks?

Is your AAV closing all the way when the engine is up to operating temp?

Just trying to think of the things that caused my problems over the weekend...

(new 2.0 FI install :^) )

Ben



[This message has been edited by willisb914 (edited 05-23-2000).]

[Germain]

Thoughts.

1) Check Timing

2) Check Aux Air Reg. If this has failed, the car will idle high when warm, plug hose.

3) Plug Deaccel Valve, all 3 hoses. Use Vise Grips for a quick check.

4) Check Idle adjustment screw on the TB

5) When I place my hand over my TB the car stalls. Yours still idles, so there must be air getting in somewhere. Check The Manifold gasgets (sorry about spelling).

6) Check the Cold Start Valve, Annoying thing to check, just unplug the wiring to it.

7) Check the fuel pressure.

8) Kick the car (this never works, but I seam to have good luck soon after it)

9) Is it possible the gas pedal is sticking and holding the idle high, or that it is adjusted so its always pulling on the lever?

This should take about 1-2 hours total. thats with 1/2 warm up time. You should be able to fly through most of this testing. If none of this helps let me know, I'll see what else I can't dig up.

Good Luck

[John Rogers]

Check the intake plenum under the throttle body for holes, especially the underside where you can't see. Our 2.0l had two holes and had been brazed in the past but the holes opened up again. If the timing is right on then get a can of carb cleaner and use the little red tube and sprey around everything on top of the engine while running. Do it slowly as the car will belch smoke when you hit the leak. Good luck.

[John Rogers]

Thought of another one, check the throttle body for cracks around the air adjustment screw.

[This message has been edited by john rogers (edited 05-23-2000).]

[willisb914]

I thought of a question I have? On my 73 2.0 FI the idle adjustment screw doesnt go all the way in? On my 72 1.7 FI the adjuster runs all the way in (spring is completely compessed) Is this normal for the 2.0 or do I need to clean the threads on the hole and on the screw?

Sorry to interupt your questions Jeremy, just wondering?

Ben

[Jeremy G]

-timing was good a couple of weeks ago but I will double check just to make sure.
-AAR is closed at warm-up
-Deaccel valve is removed(it only effects emissions right?)
-adjustment screw is all the way in
-when I place my hand over TB *nearly* stalls but stays at less then 400 but I don't understand how leak that small can cause a 2200rpm idle(see question above.) If this senerio is possible please explain
-Haven't checked the cold start because I thought it could only make for a rich mix, but I will.
-haven't checked fuel pressure but will
-thought about kicking her several times but I wouldn't want to hurt my baby.
-the throttle lever is all the back so I don't think the pedal is stuck.

Could my TPS be out of adjustment? Is there an O2 sensor? Could it be bad? Is it just a vacuum leak or is it something more complex, or a combination? Could my ECU be corrupted?

Thanks alot for all the suggestions but I'm still at a brick wall. Keep 'em coming!!

[JP Noonan]

Fuel injector gaskets go bad after awhile. $1 ea.

The rubber tubes between the intake tubes and intake phlenum should be hose clamped and/or RTV coated on the mating suface. New ones are fairly cheap.

There is no O2 sensor. The 75-76 have a "catalytic over-heat" sensor that triggers a idiot light in the dash but that's it for D-Jet.

I have found smearing RTV all over the welded seam of the intake phlenum to help (thanks Dave Darling) high idles due to vac leaks I couldn't find anywhere else.

Kcking the tires dosen't hurt the car, your foot on the other hand...

[Germain]

Well, theres a great artical. D-Jetronic Fuel Injectino for the Porsche 914. Written by Kjell Nelin. Goto http://www.914fan.net/djet.html
that address. Great artical, great process for checking of the F.I. system has problems. It took me about 3 hours to run through his entire test and repair things as neeeded.

I think this is a good place to go from here.

[surfcity914]

don't forget to make sure that the spring for the throttle butterfly is strong enough to close the throttle. my car had a sticking high idle sometimes, and i traced it to the throttle butterfly not closing completely when i let off the gas.