Fuel injection relief here!

[Tangerine]

I just got a '68 Variant with original FI. It cranks up great has a couple if issues.
1. When cold, idles fine but stumbles badly off idle until rpms are up.
2. When warm idles okay, but 'hunts' (i.e. rpms vary up and down)
and on steady throttle, misses and stumbles a little.
on full throttle, picks up and runs fine.
3. Unplugged temp sensor II when warm.
the idle rpms picked up (to about 1k) and smoothed out totally
the steady throttle smoothed out totally also.

I checked both temp sensors and they appeared to be giving valid readings,
temp sensor I 130 ohm and temp sensor II 35 ohm (both hot).
My (very limited) understanding of the FI system leads me to believe the system is running very lean since pulling the temp sensor II makes the system think the engine is cold and thus enriches the mixture.
I have not had the opportunity to check the fuel pressure as of yet.
Am I on the right track suspecting either low fuel pressure and/or air leak?
Thanks.

[tweakhx]

[Tangerine]

Thanks for the suggestion. My AAR was frozen too. I got it loose using your pictures as a guide. Unfortunately, I've got to pull it back off and try again. The bushing the shaft sits in were loose enough in mine to come out with the shaft, and I may have left one of them out.
What would be the recommended way to hunt down a vacuum leak? I've heard of spraying WD40 around the rubber hose junctions while the car is running and listening for a motor speed change. Is this valid? Is there a better way?
Thanks.
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68 Variant FI
71 SB Sedan
73 SB Cabriolet

[tweakhx]

[KTPhil]

Another low-tech way to find leaks is with the "redneck stethoscope": a hose stuck in your ear and aimed right next to each potential leak... listen for hissing. You may need an assistant since you will want to plug your other year (or use hunting earplugs). Works surprisingly well!

[Tangerine]

Thanks to your help, it's purring like a kitten.
I pulled the AAR and put the bottom bushing back in .
While I had it out, it was not turning as smoothly as I would have liked, so I used some chrome polish and spun it some more with a drill. That seemed to do the trick.
I also went back over the calibration process and adjusted the 'hot' closed setting down about half a tic. Thanks again.
I'm keeping the suggestion on the 'redneck stethoscope' in mind for the future.
I noted that the clamps on the FI fuel hoses seem to be the 'usual' screw clamps. They don't appear to be leaking at the moment. Should I go ahead and replace them (and the hose) with the correct clamps, or should I leave them alone until I have issues? I'm assuming this can be down reasonably easy with engine in car.
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68 Variant FI
71 SB Sedan
73 SB Cabriolet

[KTPhil]

Any damage from the worm clamp is done, so I wouldn't disturb it until you are ready to replace hoses, then do them all at once.

[trythis]

Hey everyone in Samba land, I have just been researching a bunch getting ready to resurrect a new to the family 70 square back and found these stainless ABA clamps at a pretty good price:
$1.04 each when you buy 10. Shipping is $6.70 with priority mail, so no gouging.

http://www.hoseclampkings.com/prod-21-1-23-52/aba-...s-band.htm

The min/max dimensions don't match up with ABA's literature. It looks like the #22014 is the right size.

I would like to know how many clamps to buy for a complete re-hosing in SAE30R9.

I am guessing 40 would cover it but may just go with 50.

Having read lots of threads on this topic, including many pages of this thread, I still don't have a solid number of feet of hose to buy.

Thanks and hopefully you're welcome on the link.

[KTPhil]

I think it was something like 21 feet of hose and 30-35 clamps, so you're almost certainly okay with 40. Search for it, and the numbers are in a thread in this forum somewhere.

[Mike Fisher]

I'm remembering 24' of hose & 34 clamps?
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https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey

[Bobnotch]

[trythis]

I am digging through my own wiring harness (rats nest) and finding that my cylinder temp sensor looks like hell and if it works, wont work for long. I can only find one available and a bunch for Porsche 914s on ebay for $100. Not so wonderful. That part is discontinued and we need something to replace it.

I was looking around the interwebs and found this ~ $25 possibility

http://www.jegs.com/i/Auto-Meter/105/2265/10002/-1
would need one of these this:

http://www.jegs.com/i/Auto-Meter/105/2259/10002/-1

I grabbed this from forums.holley.com
From Danny Cabral's post:http://forums.holley.com/showthread.php?2535-Transmission-Temperature-ECU-Input

[Donnie strickland]

Don't despair! Here it is:
https://www.summitracing.com/parts/bck-158-0112
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71 Elm Green FI A/T Squareback

[trythis]

[Donnie strickland]

Jim Adney probably has some. You can ask him at [email protected]
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71 Elm Green FI A/T Squareback

[trythis]

[Tangerine]

The fuel injection wiring loom on my '68 is in really poor shape, brittle insulation, missing boots, splices, etc. Can this be replaced without removing the engine, or is this a job that's way best done with engine out of the car?
Also, are parts for the '68 and '69 interchangable? I have been given the impression from the books I've read that they pretty much are.
Thanks.
_________________
68 Variant FI
71 SB Sedan
73 SB Cabriolet

[KTPhil]

Easy to do with the engine in the car. I did that earlier this year on my '71.

'68 and '69 should be the same. If a cold start system was retrofitted, that might be different, but I think that was a totally separate harness.

[KTPhil]

Lacking a temp sensor, you could rig up a fixed resistor based on the desired resistance when warmed up. It may run a little lean when cold, but you might not notice much. Then watch the classifieds for a spare TS.

[Bobnotch]