Fuel injection relief here!

[ziconylo]

Hi my cyl head with temp sensor for 68' squer is 311 101 375A. I found head 311 101 355D. Seems from book that inlet and exchaust valve have the same diameter 35.5mm/32mm. Simple question, will the second one fit to my engine?

[Betty Squareback]

Apologies for disappearing; got sidetracked with unexpected clutch repair. Tram, I checked the resistance on Temp Sensor 1 and found it within range at both cold and warm, so it's functioning.

To recap:
Aux air regulator is functional and currently set to "middle" setting.
Won't hold idle at cold start with temp sensor 1 unplugged.
Will idle pretty well (bettwer with a bit of help on the gas pedal) with temp sensor 1 plugged in, but eventually develops a surge. Surge goes away when temp sensor 1 unplugged.

New development:
Having connected temp sensor 1 and warmed the car up, then disconnected sensor and driven happily away, after some distance (approx 2.5 mi at 35 mph on streets, then 2 mi highway, then half a mile on streets again) I begin to notice the car is underpowered when taking off from a stop (such as red light) but will eventually (3 seconds?) pull through and gain power again. Seems to get worse with further driving, but is not totally consistent. Additionally, from time to time, I can feel this slight drop in power while car is actually in motion, and then it pulls through and goes back to normal.

What is the proper "Let's start at the beginning" way to work through the troubleshooting? The cold start issue may be distracting me from a separate issue. I go often get a backfire when letting my foot off the gas in shifting between 1st and 2nd, could an exhaust leak be part of the problem?

One thing I know for certain... is that there is a lot I don't know.

Thanks, guys, for lending your learned ears and fostering another confuddled newbie.

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[KTPhil]

Have you checked for vacuum leaks at all hoses and from the MPS?

These can cause surging, hard starts, random odd-running.

[Betty Squareback]

Not methodically, and this seems like a sensible first step. Is there a straighforward procedure for this?

[Betty Squareback]

Just read JSMskater's thread on airleaks. My 'surge' may fall into his description of 'hunting'.

It makes sense to me that a leak would cause worse performance as the car heats up (warmer hoses are more pliable). But then a lot of nonsensical things make sense to me.

Although my backfires are at deacceleration, they may be a separate issue.

I will take carb cleaner in hand and follow the steps outlined in the thread to see if I can locate something.

Many thanks!

[Tram]

[Betty Squareback]

There is some light cracking at the mouth of the molded elbow that connects the air cleaner to the Intake Plenum (thanks, Collin, for the pocket dictonary). I wonder if this be the source of Too Much Air at the Intake? If so, is this a part I generally find new, or something I have to beg borrow or steal?

Exhaust Leaks, I understand, are harder to locate. Do I just 'listen' or is there another clever method?

[JSMskater]

[Betty Squareback]

Thanks, I'll try the 'choke the throat'. With this many places to look, narrowing down to one side or the other is a definite help.

[First Fasty]

Hi,
I am a newbie to the site and to VW's, especially the Type 3. I just bought a 1970 Fastback with automatic tranny and fuel injection. The car was converted to propane in the 70's.
Any chance anyone can tell me how tough it might be to switch it back to original? Ideally a step by step procedure would be awesome.
At this point I've only had the car a few days so I know very little about it but I would like to have it run on gas eventually.

Thanks so much,
Mike
First Fasty

[KTPhil]

[Mike Fisher]

Buy a brown
VOLKSWAGEN SERVICE MANUAL Type 3 1968 through 1973 by Bentley from www.amazon.com
Get a used 1974 edition that has the Color wiring diagrams.
_________________
http://s169.photobucket.com/albums/u236/mr_bojangles500/
69 FI/AT square Daily Driver
66 sunroof,67,71,71,71 AT,72,72 AT Parts
56 & 57 oval ragtop $2,500

[First Fasty]

Thanks KTPhil.
That's kinda what I figured.
So fuel pump, pressure regulator and hoses you figure? I have the gas tank, just need to reinstall it after I take out the propane tank. That is if I decide to change back.
Is there parts I'm missing?

Thanks,
Mike

[KTPhil]

[rfalcojr]

Just bought a 69 square with auto trans and FI. Previous owner said it ran but it had been sitting for "a couple of months." Based on the smell of the fuel and condition of the brakes, I'm sure it had really been sitting for years.

clean out tank, and fuel lines (lines had previously been replaced), flushed out fuel pump(with diesel) and installed fresh gas and new battery, it started right up and ran. Fixed the brakes and went for a test drive. It ran good for a mile or two but then was hesitating pretty bad and then lost power and died on me.

got it back, and started with the basics - new points, cap, rotor, wires, plugs (correct Bosch plugs) adjust valves (they were really out of adj.) oil change
and cleaned out air filter - still no start

I've read every page of this thread and I'm an ASE L1 certified Master Tech (25 years experience) and Star certified Mercedes tech. (not bragging, just wanted to let you know that I know what I'm doing and have done my research)

I checked everything - cyl. head and air temp sensor within spec (when cold), fuel pressure 29psi when cranking, relays are good, power and grounds are good, contacts in distributor are working (used a waveform viewer to compare both signals are the same). I have injector pulse at all four injectors although its not lighting up the noid like a modern system, I'm assuming that's due to the lower voltage used for the injectors in this system. I pulled the injectors and turned it over, I get a stream of fuel out of each injector, not the usual fine mist or spray cone I would expect. Is this normal on these?

The engine runs when carb cleaner/starter fluid is sprayed into the throttle body but dies out like its not getting fuel as soon as i stop spraying. This is such a basic system compared to what I'm used to working on that I can't believe I'm having this much trouble. I must be over looking something.

Where do I go from here?

[Tram]

[KTPhil]

I am betting the bad injector pattern is the clue-- probably clogged from sitting for so long, or from crud that made its way to the injectors and their mesh screens. Liquid fuel doesn't burn, gas vapor does.

When replacing them, did you make sure the small injector seals were in good shape? Large air leaks there can foul the mixture in strange ways.

[donwtalley]

I'm looking for a good, inexpensive Electronic Fuel Injection system (kit) to put on a 1964 356C Porsche engine. Do you know of one?

[Tram]

[rfalcojr]