Seeking Diagnosis for new issue / „sputtering“, Hesitation suddenly started happening... Options

[MikeInMunich]

Hi again from Munich gentlemen! (IMG:style_emoticons/default/beerchug.gif)

First off, thanks to all who chimed in recently on the alternative heating ideas.

Here’s a glitch in the Matrix story. I was driving my D-Jet 1973, rebuilt 1.7 to 2 liter...which has been running essentially perfectly, and I thought to myself, „this thing needs nothing, and it should stay that way for quite a while. What could go wrong?“ Well, that algorithm of the virtual reality we‘re living in picked up on those thoughts and WHAM! 10 minutes later my car was all of a sudden running like crap! (IMG:style_emoticons/default/blink.gif)

The weather was the same as yesterday, when everything was fine on my nice Sunday drive in beautiful Upper Bavaria. The gas is the same. NOTHING has changed! The symptom is a slight hesitation and loss of power, seemingly only below 3000 RPM. It’s NOT causing a „bucking“ and it feels like a slight but very noticeable „sputtering“. If I were to acoustically imitate what it FEELS like I would kinda make a sound like a cat purring. It does also SOUND differently, but it would be difficult to notice for anyone other than a 914 guy. When I accelerate into the higher rpm range, like above 3500, it seeems to run normally / i.e. the symptom goes away.

The engine has 11,000 km / 6,700 miles on it. The distributor is electronic, so no points or rotor. The TPS plate is new. My grounds are all solid and volt meter is stable. My fuel tank is refurbished and filter is new. I haven’t pulled the plugs to look at them yet for signs of non -combustion, which I’m thinking is kind of a first thing to do. Haven’t had time yet. I drove home this afternoon after this started, swapped cars and went to baseball practice.

Question one: At what intervals should the valves be adjusted? (IMG:style_emoticons/default/idea.gif)

Could it have something to do with a „sticking“ valve?

I’m also thinking an injector may be malfunctioning. Thoughts?

Other possible culprits?

Thanks for sharing your thoughts and experience. Looking forward to reading what y’all think.

M.i.M.

[76-914]

Odd noise? Might want start with a leak down test. Compression check at a minimum. Then move on from there. (IMG:style_emoticons/default/beerchug.gif)
EDIT: I adjust my Type 4's valves every 3,000 M. I should add that 3000 m equates to about 4 years with that 914.

[MikeInMunich]

Odd noise? Might want start with a leak down test. Compression check at a minimum. Then move on from there. (IMG:style_emoticons/default/beerchug.gif)
EDIT: I adjust my Type 4's valves every 3,000 M. I should add that 3000 m equates to about 4 years with that 914.

Well, I’m up to at least 5,000 miles since my last valve adjustment, which was the very first one. I highly doubt I’ve lost compression anywhere. I also forgot to mention that when I’m at about 3000 rpm and accelerate, the symptom goes away in the higher rpm range. Again, the engine was rebuilt, broken in properly and is IMO solid.

[mgphoto]

6k on the valve adjustment.
Check engine ground wires FI and tranny ground strap.
Check rotor and cap for cracks.

[MikeInMunich]

6k on the valve adjustment.
Check engine ground wires FI and tranny ground strap.
Check rotor and cap for cracks.

As mentioned in post, ignition is electronic and parts are new, as well as all grounds...solid and no fluctuations in volt meter.

Thanks anyway. (IMG:style_emoticons/default/beerchug.gif)

[TheCabinetmaker]

Mg mentions the cap, but you did not. It can crack. I would also look at your trigger points. TPS needs to be adjusted and cleaned occasionally.

Edit: with that many miles on it I would do a complete tune-up. Valve adjustment, oil change, plugs check your vacuum lines, timing, Etc.

Spending the afternoon with it. Give it some love. Lol

[mgphoto]

6k on the valve adjustment.
Check engine ground wires FI and tranny ground strap.
Check rotor and cap for cracks.

As mentioned in post, ignition is electronic and parts are new, as well as all grounds...solid and no fluctuations in volt meter.

Thanks anyway. (IMG:style_emoticons/default/beerchug.gif)

Bought a new 123, had a glitch, swapped the cap and rotor, glitch gone, just saying.

[MikeInMunich]

6k on the valve adjustment.
Check engine ground wires FI and tranny ground strap.
Check rotor and cap for cracks.

Sorry. Clearly my own ignorance was showing with my previous reply. I had a different concept of what an electronic distributor looks like inside.

I took the cap off and all 4 terminals seem to be quite worn and pretty carbonized / black. Here are some photos...









Due to data limit per post, I’m putting 2 more photos below. I’m having a real problem getting the second clip back onto the cap. I’m missing about 2mm and can’t stretch the clip over the lip of the cap. (IMG:style_emoticons/default/mad.gif)

Should the terminals look like this after only 6,000 miles? Do they look bad?

Thanks!

M.i.M.

[MikeInMunich]

What’s wrong? I cannot get the 2nd clip back over the cap!

[MikeInMunich]

Photo of distributor...

[Mblizzard]

Mike I know it is simple but I have done it!

Make sure you are orienting the cap correctly. If you removed and replaced the plug wires you may have the notch on the wrong side. The notch is shown clear in one of your photos.

[MikeInMunich]

Mike I know it is simple but I have done it!

Make sure you are orienting the cap correctly. If you removed and replaced the plug wires you may have the notch on the wrong side. The notch is shown clear in one of your photos.

Ah ha. Thanks Mike!