So I got this '74 2.0 and I got a few issues with it but I'm not sure if its just me or its suppose to be like this. I guess what I'd like to do is get a post purchase PPI so I can prioritize my list of things to fix first. Here is the list of things so far:

1. Starter system - cranks slow and sometimes not at all. Pulled the battery and had it load tested okay. Cleaned the ground at the battery and where it ties to the chassis above the HH. Cleaned the hot side of the battery cables as well and still same problem. Next, I guess is the trans/chassis ground, alternator light on when key is turned to "accy" and off when running. Seems its charging when I get it running since it hasn't gone dead.

2. FI - I get a bucking at ~2.8KRPM and when I come off the pedal as well at varius RPMs.

3. Suspension - pretty hard ride, front and rear sway bars (stock) and pretty sure it needs rear springs. What about the shocks? Looks like Bils in the back and Boge up front.

Anyway, sure could use someone elses experience to take a look. Been lurking here on and off for several years, finally broke down and bought a car. Here it is.

I get the bucking too. 75 1.8

I've asked about it here once before. Nobody knows what it is. Or atleast doesn't want to tell me. One of the local guys thinks that it's a fuel line cinching under a certain amount of pressure. And a few guys here thoought it was the distributor. But it wasn't.

The starter ground connects to the engine. I wired mine straight to the battery. Cranks like a bat out of hell now.

Some of your shocks might be siezed. But that's kinda unlikely. Are any of those aftermarket shocks adjustable? Some guys seem to think that harder is better, performancewise. So they adjustable shocks and set them to the hardest settings. Nuts!

QUOTE

Next, I guess is the trans/chassis ground, alternator light on when key is turned to "accy" and off when running.

Definitely clean the ground strap between tranny and body at both ends.

The alt light should come on with ignition on, and go off when running.

Someone had a great website on the d-jet and diagnosing problems. Wish I could find that now, I think it described possible sources for the bucking.

This car is a weekend driver, so I'd like to get a "softer" ride out of it. Haven't been bitten by the AX/DE bug yet but you never know. I know for sure I need rear springs, as others here have pointed out. Back end seems to be sagging.

are all of those the reason you bought a 914 instead of a miata. Seriously, I don't see any of your issues as a major problem. The alt light is workign fine and may even glow faintly at night at idle. My 84 jetta did the same thing. However I would replace the battery cabels even if they look good. Make sure all of the cooling tins are around the alternator as they should it needs to be cooled to work as it should. I would also recommend a new volt regualtor if you still have the bosch unit. It is the big(size of a pack of smokes) silver can on the circuit board in the engine bay. Replace it with a solid state unit. The suspension is hard and was from the factory, that is normal. In regards to the bucking, it is an old FI system and will not be as smooth as anything modern. however, you may just want to clear up the throttle body and start simple (look at the throttle cable). Your issues at 2800 may be due to the throttle position sensor. Check this out http://www.pelicanparts.com/techarticles/9...ttle_switch.htm
http://www.pelicanparts.com/catalog/shopca...j_pg2.htm#item5

At or about 2800 the switch or the distributor does something that can cause this (I think it may be actually at 3200RPM)


More than you want to know about 914 fuel injection
http://members.rennlist.com/pbanders/

from brad site go to "D-Jetronic Parts Table, Setup, and Troubleshooting" --> toward bottom of page in chart look for "Throttle Switch" in right hand column.

QUOTE (kconway @ Mar 24 2006, 02:33 PM)

Someone had a great website on the d-jet and diagnosing problems.  Wish I could find that now

That would be Brad Anders site.

Thats it!! Thanks.

Regarding the "bucking" issue, check for worn throttle switch contacts.

QUOTE (wilchek @ Mar 24 2006, 02:33 PM)

are all of those the reason you bought a 914 instead of a miata. Seriously, I don't see any of your issues as a major problem. The alt light is workign fine and may even glow faintly at night at idle. My 84 jetta did the same thing. However I would replace the battery cabels even if they look good. Make sure all of the cooling tins are around the alternator as they should it needs to be cooled to work as it should. I would also recommend a new volt regualtor if you still have the bosch unit. It is the big(size of a pack of smokes) silver can on the circuit board in the engine bay. Replace it with a solid state unit. The suspension is hard and was from the factory, that is normal. In regards to the bucking, it is an old FI system and will not be as smooth as anything modern. however, you may just want to clear up the throttle body and start simple (look at the throttle cable). Your issues at 2800 may be due to the throttle position sensor. Check this out http://www.pelicanparts.com/techarticles/9...ttle_switch.htm http://www.pelicanparts.com/catalog/shopca...j_pg2.htm#item5 At or about 2800 the switch or the distributor does something that can cause this (I think it may be actually at 3200RPM) More than you want to know about 914 fuel injection http://members.rennlist.com/pbanders/

The bucking is so bad that you can't even drive through that rpm range. This isn't a "smoothness" problem. It's like the bucking when you pop start your car. SHAKE JERK SHAKE JERK.

See. Nobody understands.


Except maybe Rand.

Where are those contact switches?

Switch is on the side of the throttle body. But your problem being that bad sound more like a fuel or spark issue if you ask me.

Switch Function: Senses throttle opening (not closing), sending pulse signals to the ECU to richen the mixture for acceleration. Also senses when the throttle is closed at idling, sending a signal to the ECU to provide idle mixture compensation. Also sends a signal at wide-open-throttle, but this signal is not used by the ECU for full-load enrichment, which is handled by the Manifold Pressure Sensor.
Failure Modes: Track Wear: Over time, the wiper track for the accelerator function will wear. Wear will be especially high at moderate to light throttle angles, corresponding to part-load cruising. Click here for a link to a 60X photo of accelerator track wear. While this TPS track is still good, the re-deposition of gold worn from the contact fingers by the wiper can be seen, and eventually will become sufficient to bridge the traces. This wear causes arcing and poor contact, resulting in the car "bucking" at a constant throttle angle. "Bucking" is a fairly common complaint and is almost always due to track wear. Check by disconnecting the harness plug to the throttle switch and driving at a constant throttle angle under part-load. If the bucking is gone, it's due to the swtich.
Maladjustment: The throttle switch needs to be precisely aligned to ensure that the idle switch is properly actuated, and that the full extent of acceleration is covered over the range of operation. Poor idle performance and transition to full-load are affected if the switch is maladjusted. The Pelican Parts web site has a very good article on how adjust the switch, using an ohmmeter.

Notes: The car will still run even if the throttle switch is removed! It will accelerate slowly, and the idle may be poor, but it will run. Proper adjustment of the throttle switch is critical. If the idle switch does not actuate when the throttle is closed, the idle circuit in the ECU will not be activated and poor idle performance will result. Additionally, cars with ECU's that provide over-run fuel shutoff will not shut off the fuel if the idle switch isn't actuated when the throttle is closed while coasting. Proper adjustment of the throttle is also important. If the throttle cable and pedal stop are not properly adjusted so that the throttle is completely open when the throttle is fully depressed, fewer acceleration pulses will be provided to the ECU for acceleration enrichment, and you'll be restricting your full-throttle input, reducing horsepower.

I recently found out about two products that can be used on the contact tracks to extend their life. Deoxit D-5 cleans and leaves a lubricating film. It's available from CAIG Laboratories ( http://www.caig.com ). Another similar product is Stabilant 22 (VW part # ZVW 186001, Car Quest # SL-5). To use, you must open the throttle switch - be careful, there are some rubber positioning blocks that may fall out. Spray the contact track area and use a Q-tip to remove any excess.

And if it's an L-jet 1.8 the vane in the Vane Airflow Meter could be sticking.

Should I be able to see the ground strap that attaches between the trans and chassis easily? I had my head up behind the rear wheels looking at both sides but didn't see any strap. I'm gonna get the jackstands out tomorrow but I figured I should be able to see it while its on the ground still. The trans was rebuilt recently and I wonder if they left it off? Is there a dedicated stud on the trans?

Yes. Jack up the drivers side and look behind the drivers side rear wheel for the flat braided strap. With the suspension extended/wheel lower there's more room and you can access it easier. Still a bit of a pain to clean the body end.

Lets just say this strap was not on the car. Would the car still start and operate without it? Car does start, but cranks real slow and drives fine (rest of the electrical okay as far as I can tell).

Just looked and the damn thing isn't even there. I see the nut on the chassis where its suppose to attach. Is there a specific nut or bolt it goes under on the trans?

I just grabbed a cell-phone camera shot for you.

Just looked and the damn thing isn't even there. I see the nut on the chassis where its suppose to attach. Is there a specific nut or bolt it goes under on the trans?

Thanks Rand. Appreciate the snapshot.

There's a stud on the tranny. It points toward the rear of the car. Can't see it in my photo because the tranny mount is blocking it, but it would be a couple inches or so from the lower right of the red circle.