'76 2.0 idle problems (wants to stall) Options

[type4org]

Hi everyone,

I just purchased my very first 914 (yay!), a low-mileage 1976 with the original D-Jetronic-powered 2.0. Since I had time to do something utterly crazy I drove the car all the way from the place of purchase (Salem/OR) to where I live in Virginia, 3 days straight...

Anyway, it does have one niggling problem: The idle is so low that
the car wants to die every single time I let go of the gas pedal, and
it barely catches itself most of the time.

The engine is the original GC 2.0 with the original fuel injection.
This is my first 914 and my first D-Jetronic car, I am used to the
1.8 L-Jetronic engine which my '74 412 has, and with those I would
know where to adjust the idle speed.

I know there's some underlying problem somewhere, and any ideas are
greatly appreciated, but I am also looking for a band aid that gets
the idle up so I can use the car, this is quite urgent for me since
the 914 is currently my only car. Where do I adjust idle speed on
that engine?

I'm not sure if the effects would be the same on the 2.0, but from
lurking for a long time on the VW Type 3 list I know that faulty
voltage regulators and low system voltages can make the D-Jetronic
run very poorly. The reason I am mentioning this is that the volt
meter gauge in the middle console seems to indicate low voltage. It
shows 13 volts with the engine running and nothing switched on, but
even at highway speeds switching on the headlights pushes it down to
12. The turn signals causes it to dance between 11.5 and 12.5 in sync
with the signals. Maybe there is a connection? Yes, I do realize that
gauge isn't all too precise, but it seems to me with the alternator-
driven system the voltage should really stay stable at 13-13.5 V.

Any (emergency) help appreciated! (IMG:style_emoticons/default/smile.gif)

[pfierb]

The meter needle on my 73 2.0 does the same thing when you apply the brakes use the turn signals etc.etc. seems to be the nature of the beast....I wouldn't worry about it. Not sure if your 76 is the same but the idle adj.screw on my 73 is down behind the air filter you can adjust it with your fingers no tools needed.
Paul F.

[tod914]

There's an idle screw on the throttle body... try adjusting that.. u can reach under the aircleaner and turn it by hand. On the computer there is a knob.. turn it all the way clock wise.. that will increase the gas at idle too. Id turn the comp knob all the up 1st then adjust the idle screw. No harm in having it running alittle rich.

[tod914]

when u get a chance, have the valves and timing adjusted. Maybe put in a pertronix electronic ign.. think they are about $70.

[type4org]

when u get a chance, have the valves and timing adjusted. Maybe put in a pertronix electronic ign.. think they are about $70.

The car had been to a shop before I bought it and they did a basic tuneup then. But to be honest I don't have much trust in them, they knew the low idle (and see-sawing) existed and still said "this car is in excellent condition". Which, in all fairness, it is, but standing for most of 30 years takes its toll.

[type4org]

There's an idle screw on the throttle body... try adjusting that.. u can reach under the aircleaner and turn it by hand. On the computer there is a knob.. turn it all the way clock wise.. that will increase the gas at idle too. Id turn the comp knob all the up 1st then adjust the idle screw. No harm in having it running alittle rich.

Thanks, I'll try that this afternoon. I knew about the richness adjustment on the ECU, but wanted to try idle speed initially. I'll play with both.

I did not think it was richness so far because the engine starts up fine, cold or hot. It just falls into this hole the moment you let off the gas, as if the gas supply is cut off completely for engine deceleration and is supposed to cut back in close to idle. The engine has all the emissions "goodies", so who knows :/

Oh, and on the highway it seems to do just fine. Aceleration seems OK and smooth once the engine is warm. However, I don't trust my judgment yet - the only comparison I have is my '74 412 wagon with the 1.8/EC engine, this (emissions-throttled) 2.0 seems to be only marginally more powerful (IMG:style_emoticons/default/blink.gif)

[type4org]

There's an idle screw on the throttle body... try adjusting that.. u can reach under the aircleaner and turn it by hand. On the computer there is a knob.. turn it all the way clock wise.. that will increase the gas at idle too. Id turn the comp knob all the up 1st then adjust the idle screw. No harm in having it running alittle rich.

Found the idle speed screw. I'm surprised how easy it is to turn by hand. I could not find the ECU richness screw - could it be that it's not reachable with the ECU mounted?

[tod914]

The ECU knob is on the top left side of the unit. I think your unit being a 76 is mounted on the firewall. Its about 1/2" in width and sticks out the top.

[type4org]

The ECU knob is on the top left side of the unit. I think your unit being a 76 is mounted on the firewall. Its about 1/2" in width and sticks out the top.

Thanks Tod, I'll take a look at that later. The idle adjustment already brought some relief. It still feels like it drops into a hole when letting off the gas, but it catches itself earlier and stabilizes into a higher idle now. Yay, I can go to the store again (IMG:style_emoticons/default/wink.gif)

[brp914]

Posted Jul 15 2006, 10:15 AM
There's an idle screw on the throttle body... try adjusting that.. u can reach under the aircleaner and turn it by hand. On the computer there is a knob.. turn it all the way clock wise.. that will increase the gas at idle too. Id turn the comp knob all the up 1st then adjust the idle screw. No harm in having it running alittle rich.

I disagree - its not a little rich, its alot rich. you'll waste fuel, increase emissions, contaminate your oil, and accelerate engine wear.

rather than piling on a series of random mis-adjustments to compensate for underlying problems and/or other misadjustments, please do the sensible thing. get a haynes manual and basic tools (timing light, dwell, volt meter, vacuum gauge, fuel pressure gauge, compression gauge) and tune to specs. do fuel mixture last, and if you dont have it done by a pro, give it only the minimum amount in order to run well. good luck and (IMG:style_emoticons/default/welcome.png)

[type4org]

rather than piling on a series of random mis-adjustments to compensate for underlying problems and/or other misadjustments, please do the sensible thing. get a haynes manual and basic tools (timing light, dwell, volt meter, vacuum gauge, fuel pressure gauge, compression gauge) and tune to specs. do fuel mixture last, and if you dont have it done by a pro, give it only the minimum amount in order to run well. good luck and (IMG:style_emoticons/default/welcome.png)

Absolutely - this is only a band-aid to make sure I can use the car without total embarrassment at stoplights. It will go to the shop some time next week for a full tuneup, oil change, and a complete gas/vacuum hose replacement. Those vac hoses look like they were in there from day 1.

I have actually ordered the Haynes a couple hours ago (IMG:style_emoticons/default/wink.gif)

[tod914]

Do yourself a favor and pull the gas tank, inspect the inside and replace the lines and fuel filter too. Easy job. Sounds like your on the right path bringing it in for a full service.

[type4org]

Do yourself a favor and pull the gas tank, inspect the inside and replace the lines and fuel filter too. Easy job. Sounds like your on the right path bringing it in for a full service.

The shop where the car got the basic tuneup before purchase already replaced the filter (they replaced the fuel pump as well since it was broken), so I should be fine on that count. I'll have my shop here in town work on the hoses first and take a look at the filter to see if it's full of crud, after that I'll consider taking a closer look at the tank itself. Without any place to do the work and no tools nothing is easy (IMG:style_emoticons/default/wink.gif)

[tod914]

You'd really be surprised, despite not haveing a big area to work, most of this stuff you can do where you park it. vaccume hose replacement, tank inspection, etc. To inspect the tank you just need to remove the hex nuts (i forgot the size 6 or 7 mm i think) pull the plastic portion off and look in with a flashlight. A small tool kit can be aquired fairly cheaply, and the Haynes book will certianly be invaluable. Overall for basic things, they are pretty simple cars. Good luck with car and post some pics when you get a chance. AutoAtlanta has a nice vacume line kit with instructions btw.

[type4org]

Good luck with car and post some pics when you get a chance. AutoAtlanta has a nice vacume line kit with instructions btw.

I have to get the pictures I took before and during the trip from the west coast from the camera and will put them up on my site.

Thanks for the hint about the vacuum line kit, that's excellent.

[type4org]

Just a quick Thanks to everyone who chimed in. It seems with the ECU richness adjuster I have hit paydirt as far as the "band-aid to keep me rolling" is concerned. Just idle speed alone would still lead to near death when letting off the gas in neutral, but moving the ECU adjuster four clicks clockwise (seems about 1/8 turn) made a much greater difference.

Man is that thing fun to drive when it runs better! It's absolutely delightful, despite all the emissions-related "emasculation" of that '76 engine (IMG:style_emoticons/default/smile.gif) After coming from a 412 wagon this feels like a go cart.

[ws91420]

(IMG:style_emoticons/default/welcome.png)

Hey there fellow Fredericksburgian. I will have mine here after next weekend if all goes well. See this thread http://www.914world.com/bbs2/index.php?showtopic=55935 . I also have a 76 which I have convert from FI to carbs.

[type4org]

(IMG:style_emoticons/default/welcome.png)

Hey there fellow Fredericksburgian. I will have mine here after next weekend if all goes well. See this thread http://www.914world.com/bbs2/index.php?showtopic=55935 . I also have a 76 which I have convert from FI to carbs.

Thanks a lot for letting me know about this. I'd love to come along and added a reply to that meeting announcement thread. Caravan from Fredericksburg maybe? ')