Well I have been slowly collecting parts over the past few months to go back to FI. Did not hate my carbs but I always intended to go back to FI. Shortly I will have an exceptional deal on a carb set up.

I am going to start checking out the electrical issues tomorrow. Currently there are no relays in the engine bay board. So I am assuming at some point the PO wired the fuel pump directly to the ignition switch and it is always on. As I am going back with 73 fuel D-Jet injection on a 2056 I know the fuel pump is only suppose to run for a few seconds when starting. I was wondering what the impact of using the fuel pump it its current always on would be?

Also is there a good source for the original type vacuum lines? Also need a 2.0 air filter.

More frustration to follow I am sure. Any suggestions as what to watch out for would be helpful!

Vacuum Line Kit: http://www.autoatlanta.com/Porsche-Vacuum-...BAAVACKIT3.html

Includes hose diagram.

What is the carb setup????
Interested here.

I got my vacuum lines (by the foot) from Pelican. There is a diagram there too.

Am I correct in assuming you tried using the carbs but still had the stock FI cam in the engine. If so, carbs are not quite compatible with the stock FI cam. If you go back to FI will you also have to change the cam again?

If you need a working FI setup to look at, let me know and I will come over. I have extra relay boards, relays, and other miscellaneous FI parts I can bring with me in case there are any issues with the items you have.

Autoatlanta for the hose kit. Might as well get the air filter from AA as well.

Did you get the FI parts for a '73 or '74 system? There are some small differences.

steve


PS: dibs on the Tangerine cable throttle linkage

In the heading I first thought you meant you were going back to FLORIDA. My eyes are tired.

Less than 1-year old Weber 44s with vents ranging from 28 to 36. Numerous idle jets 40 to 75. Mains 1.15 to 1.55. F11 tubes. Tangerine racing linkage. Rotary 3.5 psi fuel pump.

It still has the FI cam which is why the carbs were ok but not great. Don't get me wrong the carbs had a kick but as you said unless I was willing to split the case I was leaving performance on the table.

If you've got a choice of FI systems, use L-jet.

73 and you are on the list when the trouble shooting starts!

Not sure I can go the AA route. Bit of a sore spot. Have done small things so I will have to see.

Is this Tim? That is a very true statement I have been educated by Tim but I am afraid I have to go with the stock D jet.

Stay with the 73 setup.

I am doing the same thing.

It is likely that the high-pressure FI fuel pump was replaced with a low-pressure carb one. If that is the case, you'll need to switch back to the high-pressure pump.

There are a bunch of ways to wire the pump for carbs. Many of them involve hacking up the wiring in the car, some do not. Many do not use a relay (or even a fuse!!!) to protect the circuit, some do.

The stock FI setup uses a relay to operate the fuel pump, and has a fuse to protect the circuit. That is definitely better than not having either or both.

Having the pump run the whole time the key is on should not affect how the car runs. The way the pump is controlled in the original setup is mostly so the pump will get cut off if the engine stalls, possibly as a result of an accident.

--DD

Thanks Dave. I hope to wire it back as it was originally designed with the relay and fuse. But the wiring on the car was less than perfect and done with wire nuts in may places so I am expecting to do a lot of work to put it back right but wanted to test things out before doing all that.

While it may be frustrating getting everything sorted out, I think your decision is a good one with a stock cam. I am quite impressed with D-jet!

Last year Joe Sayre, a local guy to me went with D-jet on his 2056 build and is pushing out 130 or so HP.

The vacuum line kit from AA is the ticket...everything is pre-cut.

I went with the later 914 style high-pressure two port Bosch fuel pump from GPR.

Good luck & keep us posted!

the stock FI pump wiring may still be lurking somewhere. look for it.

All sizes of hoses can be had by the meter from bughaus and other vw suppliers

What do you think about using a '74-> D-Jet system? The '73 has a couple of MY73 unique parts (resistor in head temp sensor circuit or the sensor itself? ECU, MPS?) that might make it easier to source 74-> replacement parts.

Mike - I found it best when replacing vacuum hoses to have additional length to work with. I agree with buying more length of hoses in the sizes needed and you'll be assured that it will fit with your particular needs. I tried the AA kit and found a couple of the hoses didn't quite fit in my case I ended up buying more. Plus, you'll save $$ by not buying AA's kit. Jon

See PBAnders thorough write up on D-Jet. He recommends the 74 set up as there are more parts availability. Works and looks same as 73 D-Jet.

The 74 setup may be the better setup. Most important is to make sure all components match for the year. Do not mix 74 and 73 parts. This includes the CHT, MPS and the ECU

From what I can tell that considers mostly the dizzy which has a different advance curve on the 74.

Since there are rebuilt kits for MPS available now....and if it is going to be tuned anyway.... should be fine. I am going to leverage a 1.7 core MPS.


I am going with all the other 73 components since they leverage some 1.7 parts namely the ECU.

All the other stuff is readily available from what I can tell.

Well the 2.0 dizzy is installed. Fried my electronic somehow and had to put points in. Carbs out, vacuum lines routed, fuel lines installed, and just a few things to add before testing starts.

Anyone seen my deceleration valve?

Haven't seen. Good move away from carbies.

Interesting discussion...I'm on the fence, I have questions but I don't want to "jack" this thread so I will start another one to get input on my situation.

My type of guy!
I would take either FI setup over the carbs, super glad you are going this route! I'm at your disposal with this conversion, but I have to admit that I have little knowledge with Djet.

I am running my 74 2.0L D-Jet without decel valve. No issues. You can always hook one up later.

It will not make a performance issue.

Without the decal valve, more stress is put on your MPS diaphragm from the sudden acceleration/deceleration...all the groovy people run the decel valve.

Well it started on the first try

Number 4 injector is not firing and it is idling high due to vacuum leaks but it runs!

As it is written by the master, it shall be!

wait wait wait, did I miss the progress thread on this conversion or is it located in the sandbox

Did you check the CHT?

Not much progress to document. Take carbs off put FI on!

I did not check the CHT. Would that give a high idle? Do I have to remove to check?

Need to figure out how to test the injector. The other three seem to work so I not think it is the trigger points. All of the injectors are new so the should be good. Will swap them out to see if the problem follows the injector. If not then I will have to do some checking of the wiring. I am just amazed it started on the first try!

Do you have a price on your old Carb set-up? I have a '74 2056 set-up that it will work great on(will be installing new cam).

Always check the CHT, yup, the CHT, gotta check the CHT.

Well I had one inquiry all ready but I would like to sell the complete package. I have not sorted everything yet but they are 44s with less than 500 miles on them, vents from 28 to 36, numerous idle jets to 75, assortment of air correction jets, and mains. Have the CPI rotary fuel pump, Tangerine racing linkage, snail gauge, weber tech manual, and even the hex bar! Once I get an inventory I will post.

What is the procedure for checking the CHT?

Gonna run FI yer gonna need a multimeter....

Glad it fired up.

Yep. got one! Two actually. Found the check procedure.

I you installed the complete D-Jet, then it should idle high when started cold as the AAR (Aux air regulator) is open until it warms up.
Tom

one way to check the injector is to put it in a small glass jar and crank it , you should see it squirt , or not. remember the injectors in d-jet fire in pairs so if it is only one injector not working its most likely a clogged injector, or could be just a bad injector, - you can swap them, say switch it with another and retry, if it is the same thing then you know whether its the injector or the connection. make sure the grounds are good
- on another note- regarding vac leaks, high idle is normal during warm up, but if the aar works, it will slow down as it warms up. - i had a leak between the plenum and the throttle body, and also where the intake runners attache to the plenum. once those were air tight i was able to get the idle down to about 1000, at that point i had an issue with the CHT - a lean running engine will idle high or even hunt and that can be the MPS, but i am getting too far ahead on this.-- test the CHT test the AAR, i assume you tested the MPS for vac already, -
interested to know how the injector tests out.
PW

Is there a source for new AAR's (cold start valve)?

no- but, you sometimes can clean them out and get them to work, if they are stuck , not opening or closing all the way, do a search, someone here ahd done a thread on rebuilding them. but every once and a while you will see a used operating one for sale. you can place an WTB in classifieds. I would check with Bruce Stone, he seems to have some of almost everything.

oh, the AAR is not a cold start valve, those are 2 different items. - the cold start valve is an injector essentially. the AAR only controls air, it is a controlled vac leak in a way, adding extra air on cold start, closees slowly when heating up and then the idle will come down to the normal 800 or so if everyting is as it should be.

Ah, did not realize. Always thought of it as a cold start valve & wondered why they called it an aar. Now I know. No doubt my aar is sticking open & I have to get in there & see what I can do. Now I gotta find that thread.

Spray the aar with some pb blaster, it will help lube things up inside the aar

Okay, my first attempt with Djet diagnosis.

Remove the ECU plug and lets check the resistance on pins 3,4,5,6 (at the ECU connector) to battery ground. You should have a pretty low resistance but consistent on each pin.

Since you will have this connector off, go ahead and check the resistance on pin 23 (at the ECU plug) to battery ground.

Will do this tomorrow. Went back through some stuff and found some questionable grounds and a broken wire on the temp sensor. I have a new CHT that I have checked that I will install but I have to fashion that socket to swap it out. I have to take it out to check the old one so I figure just install the new!

Cool! Before you yank the CHT, measure it at the ECU plug first (pin 23 to engine ground) This will test the continuity of the wiring harness and CHT to ground.