My Fuel Injection Restoration Thread w/pictures

[ClassicCamper]

Hopefully, I'll have a nice and smooth running engine by the time this thread is complete. Now that I have eliminated most of the ignition, vacuum, and engine (valves/compression) issues, it's time to dive into the rats nest of the fuel injection system. My end-goal is to have this engine as close to it's original reliability as possible and to restore it to its original 'glory'.

I acquired the car about a week ago. Here is what the engine looked like:

Condition: The car starts right up, but doesn't accelerate well at all. It bogs down and slowly accelerates; if I try varying positions of the accelerator, it will slowly gain speed.

Here's what I'm doing thus far:

1) Ordered two new temp sensors (one did not pass resistance test)
2) Ordered rebuilt Bosch distributor (NOT EASY TO FIND!); touching my existing distributor would cause engine to miss and change speeds, especially when trying to set timing.
3) Ordered 4 new injectors
4) Ordered fuel filter
5) PCV valve (at least for now, until I fabricate a work around)

Current project: (I'm going to try to tackle one small job per evening)

Removal of throttle body: I'm hoping to find a direct replacement TPS or one that would be compatible. If someone could give me some guidance here, I'd appreciate it. The contact surface on the circuit board looks very worn.

When I removed throttle body, here is what I found:

(if you can't make that out, it's electrical tape partially obstructing intake) Wise words, Ray about not driving this until it's completely gone over. I'm sure gummed up wads of electrical tape in the valve train aren't good for motor.

Plus, I'm sure the PO's failed attempt at an electrical tape gasket didn't help with my poor acceleration issue.

Here is what I'm shopping for now:

1) Cold Start Valve: Discovered that mine is leaking ; time to start combing the web.
2) Potentially having the FI harness rebuilt. It's big $$ (about $475) but, I feel as though some of my FI wires could crack right in half if bent as they are so brittle. We'll see.
3) A TPS switch - proving impossible to find or get an alternate part number.
4) Cooling fan - mine has a broken fin in it, probably from someone trying to line up the timing marks by jamming a screw driver in timing hole.

If anyone has any leads on the above or wants to trade PM me. (I have NOS 411 vent shades still in box, NOS T3 injectors, '73 412 Dizzy Cores to name a few)


More to follow.

[raygreenwood]

1) Ordered two new temp sensors (one did not pass resistance test) This is good.


2) Ordered rebuilt Bosch distributor (NOT EASY TO FIND!); touching my existing distributor would cause engine to miss and change speeds, especially when trying to set timing.

There are numerous things that can cause this issue and it may not need to be rebuilt. Also...unless you get the EXACT distributor rebuilt by reputable people without any advance parts or injection cam parts being swapped around from a generic parts pile....you may just make things worse. I have had "0" luck with correct rebuilt distributors in 35 years. Contact Glenn ring and have him rebuild one or simply order a bushing kit from him. Do not waste money on rebuilt distributors for fuel injection.


3) Ordered 4 new injectors

Good

4) Ordered fuel filter

Good

5) PCV valve (at least for now, until I fabricate a work around)

Skip this. The original is defective from the get go. Dont waste your money. It takes 5 minutes to do the mod. Piece of 1/2" aluminum rod about 3/4" long...drill 2.5mm hole in center to start....insert about .5" into the PCV line...reconnect hose.



1) Cold Start Valve: Discovered that mine is leaking Confused ; time to start combing the web.

Disconnect it/bypass it with the fuel line for now. Its of no use unless its below 40F. Get things running right first and goo back for that . you have months to play with cold start.

2) Potentially having the FI harness rebuilt. It's big $$ (about $475) but, I feel as though some of my FI wires could crack right in half if bent as they are so brittle. We'll see.

best thing you can do. You can rebuild it yourself for about $45 for the crimper and about $200 in parts and wire.

3) A TPS switch - proving impossible to find or get an alternate part number.

There are numerous alternate part numbers. Do you have a four wire or five wire plug....not the plug on the TPS....but the actual male plug. How many wires do you have? Chances are high that there is nothing wrong with the TPS. Great to have a spare...better to correctly adjust...and the book is poor for this. I will have a complete adjusting run down with piccs in about a week or so.

4) Cooling fan - mine has a broken fin in it, probably from someone trying to line up the timing marks by jamming a screw driver in timing hole.

Good. make sure its the right timing marks or you will have to put your own on. Ray[/b]

[ClassicCamper]

[Lars S]

[raygreenwood]

For the PCV....the aluminum rod goes into the hose just upstream of the rubber elbow. Then take the oil breather....flip it over and remove the D shaped plastic plug. You can see the inside of the PCV valve from this point.

Take a pick and pop out the plastic disc inside so its a straight through tube. Then put the D plug back into the breather and reassemble. At the very worst you may need a tweak to the knob on the ECU if you have one...or a tweak to the MPS.....but mostly just a tweak to the idle. Ray

[ClassicCamper]

Great, will try this later. Thanks for the clarification.

Tonights mission: Test (well, to a degree) the MPS as well as verify correct part number.

Here is mine inside the 73:

First issue, this MPS has the following part numbers:
VW: 311 906 051E
Bosch: 0 280 100 106

I read online that the 1973 412 1.7 MPS had the following part numbers:
VW: 022 906 051E
Bosch: 0 280 100 049

So, the part numbers on mine are not aligned with what the specs call for. So, does,this mean I need to get another one? I want to do it right, so please let me know.

Also, ran a few basic tests on it:

1) Vacuum test: Started at 10 in Hg and held for 5 minutes before it hit 5 in. Hg. 0 vacuum left after 17 minutes. Passed
2) Terminals 17-15 read 90 Ohms. Passed
3) Terminals 8-10 read 350 Ohms. Passed

Ill be curious what you all say about the difference in part numbers or what feedback you may have.

[ClassicCamper]

I decided I can't hook the old wiring harness up to all these newer parts. So, I pulled the harness:

The wires are so brittle in some areas, Im pretty sure they will eventually break.


Fwww. Done for the night.

[raygreenwood]

Sorry I cant get deep into this right now. Pot the ECU part #s...that is the wrong MPS....not even the right "type".

I posted earlier and my post disappeared I think.

Take a close up picture of the circuit board side of your TPS.

About 4 different part #'s have the same circuit board and the 4 and 5 pin female plug snaps off and is interchangeable. More later Ray

[ClassicCamper]

I'll get a picture of it when I return to the car. Now that I've discovered that the MAP sensor in the car is the wrong part, i need to find one. Has anyone dealt with this company?

It appears as though they are the only 'reasonably' priced places. I'm glad I can do the rudimentary tests on it, so I'll be able to check it out before it even goes into the car.

[19super73]

http://www.thesamba.com/vw/classifieds/detail.php?id=1604137

I most likely have all the parts you are looking for.
_________________
1970 Campmobile [url=https://www.vw-mplate.com/mplate-47260.png]Click to view image[/URL]
1970 Fastback 1600 TL
1971 Doka [url=https://www.vw-mplate.com/mplate-14845.png]Click to view image[/URL]
1973 Super Beetle
1973 Westfalia [url=https://www.vw-mplate.com/mplate-31892.png]Click to view image[/URL]
1974 412 Variant
1975 La Grande Bug
1984 Vanagon

[raygreenwood]

Auto Atlanta had excellent parts. 914 is their specialty. The 1.7l 914 and 411/412 use the exact same MPS. Same calibration as well. But..... a reman will be bench set at best. ...which means it should be neutral enough to start and run....but will require further adjustment.

Most of the other rebuilt MPS I have used over the years were so far off the car would not run. I bad to reset the inner stop and play with it until it had a baseline good enough to get running to adjust from
Expect this no matter what. If 19super73 has one for you get that and then collect another spare or two even if the diaphragm is shot. You can get those now. Ray

[ClassicCamper]

So I looked at the PCV valve and nothing is there, it goes straight through. That said, Im assuming I should leave it like that, but put a piece of rod inline with a 1.5-2mm hole in the middle? If that is the case, will the car even idle? When I pull that hose off and cover it with my finger, the car stalls.

[ClassicCamper]

One other question. I'm getting ready to clean the throttle body and noticed that the shaft seems to have some play on the side where the Throttle Switch is. Is this Ok or should I try to find a machine shop who will/can rebush this? (I mean side to side play, not in and out). Thanks!

[Lars S]

[Lars S]

[raygreenwood]

[ClassicCamper]

Thanks Ray, BIG HELP! Jeff Bowlsby is doing my wiring harness and is going to give me a correct MPS for the engine. I'm excited to get this moving. This week's goal is to get the engine out and make some much needed repairs (flaps don't move freely, want to test thermostat, paint tin, etc)

Any recommendations where I can get the correct spacers and paper gaskets for the intake runners? I'd like to take them off and put on new plenum to runner seals.

[raygreenwood]

[ClassicCamper]

It appears that the phenolic spacer on the driver side is cracked clear through and the passenger side one doesn't look that much better. Can you recommend a place that may sell them new?

Also, If I'm able to find new / aftermarket spacers (presuming I get the thicker ones so intake runners line up), do I perform the same technique you detailed above with the roller and Permatex Ultra black?

[raygreenwood]

Try the type 4 store. They used to sell them. You may have to get a complete gasket set.