[size=4]
Greetings from an old man. I'm hoping some of you younger enthusiasts can advise me on a serious problem with my 1974 914 2.0 purchased a year ago. Fine car, no rust, working well until a month ago. Began running terrible so I took it to a shop experienced in VWs. He changed: plugs, points, condensor, pressure sensor, fuel pump relay, power relay, air filter, "good compression". Told me I needed a new fuel pump and filter when it was a bad relay. I removed the car from his shop. Now its in my garage and runs too rich to drive and smokes like I used to. I need a knowledgeable mechanic in the NW Indiana area to fix this thing or you excellent owners to suggest What I should look for to repair or for said repairman. This car is too fun to drive so I can't wait for someone to make a barn find out of it. I'm unfamiliar with this forums protocol but will try and keep up. Thanks for any and all advice.
The old uncle

Hey uncle, I'm an old guy too with a 76 2.0 for the last 20 years. I too had running issues forever, doing the same things you did. It runs perfectly now, and I would recommend doing three more things. Get an electronic ignition like a Crane Fireball to replace your points and condensor. Check your Throttle Position Sensor Board on the side of the throttle body. If it has grooves worn in to it, replace it. And pull your dizzy and try another set of Trigger Points, even if you can only get a slightly used TP from someone on the board here. The TPs fire the injectors and can be a big source of running issues if not right. Finally, my car smoked too until I put in Brad Penn 20/50 racing oil. That stopped the smoking completely! Good luck! (I'm betting replacing you Trigger Points will be your answer)

Well, you are right between two of the best in the 914 biz.

Brad Mayeur in east Peoria (914 Limited)
Mark DeBernardi in Grand Rapids. (Original Customs)

Maybe one of the locals will be able to assist.

You've come to the right place!

Check out this web site to help troubleshoot:

https://members.rennlist.com/pbanders/DJetParts.htm

Keep us posted on your progress.

Vacuum.leaks are the enemy. You should replace all if the vacuum lines, elbows, etc. You can get the kit from that place in Atlanta that nobody seems to like.

whoever is closer will set you right with ease.

rich

Why would you seek advice from the "young" folks? Us old farts know more about 914s than they will ever know.

1. Change plugs: OK.
2. Points: OK
3. Pressure Sensor: Did he just order a Manifold Pressure Sensor (MPS) from Porsche or another website?

4. Fuel pump: OK
5. Power relay: OK.
6. Air Filter: OK.
7. Engine Compression Test: OK


Let me know where I can order a new MPS also.

New MPS is basically unobtanium. You can get proper rebuild kit (and I think they will rebuild as well) from Tangerine Racing.

If you have original vacuum hoses, you did not say, replace those before throwing money at other things.

Take the hose off the mps at the intake manifold and gently suck on it, see if you can make your tongue stick to the tube. If no, you may have a bad mps that really needs replacement.

After a hiatus (graduations) I'm back at it and thankful for the suggestions. Changed some vacuum hoses, called Brad at 914 Limited. What a gentleman! He suggested the cht sensor then trigger points then mps. Questions. What is the rectangular connection on the cht wire? Necessary? Can I remove air intake pipe to access the cht? How? To remove the dizzy for examination of trigger points will I disturb the timing?

That is simply a cover over the spade connector. The CHT should disconnect from the wiring harness at that point. It's not a show-stopper not to have one, but if it grounds against anything (e.g., case), it won't work properly.


Air intake? I assume you mean the engine tin? You don't need to. You need a deepwell 13mm socket. You bunch up the wire lead inside the socket. Be VERY careful threading the CHT in or out of the case, as you don't want to bollocks up the threads on the case.


It's possible to remove the dizzy without messing up the timing. But it's more difficult to remove as it's hard to get access to the nut holding it place without spinning the dizzy out of the way. Just put timing back on your to-do list (which is a good thing to check anyway).

AND check your grounds, had to do all these to get my D-jet running good- which it does, but I have had 2 MPS fail on me ,
lean running will cause surging and high idle,
bad MPS can cause lots and failure of unit car will not run, but I had one go bad, still held vac fine, but electronically was failing. usually they fail the default will go super rich, but on one of these mine did to very lean so that does happen too.
TPS will cause the bucking on acceleration , usually around 3000rpm - replacement circuit boards are available-

timing, valve adjustment and brad penn oil cured my smoking too

Ok I'm stuck and stupid. How exactly do I test the cht? Do I have to remove it? The wire insulation is cracked and separated in many places so I don't want to agrivate the problem.

You need to use an ohmmeter and check the resistance values between the wire lead on the CHT (the one that is inside that cover) and ground (say, the battery negative terminal). So, one lead from ohmmeter on lead of CHT, one on the battery ground. You will get a resistance value in Ohms (or in thousand Ohms - K-ohms). That value should vary with temperature of the head. For a 2.0, you should get something like the following:

At ambient temperature (e.g., engine cold), 2.85 Kohms (2850 ohms).
With a generally warm engine or around 200 degrees, 190 ohms.

The exact numbers are not that critical, but you should be in "the ballpark." If you see a high resistance with an engine that is warm, that's a problem -- that's going to make the mixture richer than it should be, as the ECU will think "engine is cold or cool, more fuel!" when in fact the engine does not need more fuel. That would potentially give you symptoms like you are describing of running too rich. A bad or failing CHT is very common for something like this (although it's not the only potential cause). In my experience, though, a bad CHT will generally prevent the car from starting or running more than a few seconds, which leads me to...

...the other thing to know is that it's not just the CHT itself. It's the whole wiring harness from CHT to the ECU. Based on your description of your wiring harness, your CHT could be fine but the wire that carries that back to the ECU may be bad. If it's broken, or breaking, or otherwise showing too much resistance, you're going to get the situation I described - too much fuel for the engine's condition.

If your CHT resistance values generally check out, then it's off to chase down another D-Jet suspect, like the MPS.

Thank for the help.im to the point of selling this full time job. It's a very nice car when it runs but I think that I an getting too old to learn a new skill and can't afford to keep this up

I just shipped a Stainless fuel line kit to someone in Schererville. That wasn't you was it?
Send your car here (Tangerine Racing) and we'll have it purring like a kitten in a day or two. (assuming the engine itself is healthy)

That could certainly cause an intermittent short. I would just replace it. As noted, the disconnected wire on the CHT took my 2.0 from running great to suddenly dead and needing to be trailered home. The following morning it started right up just as yours did.

Not a good test. Mine held a vacuum just fine (both The Tongue Method - copyright R_Towle - and with a Mitey Vac) but in the end proved to be bad (cracked diaphragm).

Having Tangerine repair/reman the MPS i]transformed [/i]the car into something that's now a dream to drive.

http://www.914world.com/bbs2/index.php?sho...=291477&hl=

Funny.....I always like to think that learning something new makes me feel young.

GLWT