Mtdi swap

[Sharpshooter48]

I have fought with the original injection pump, from having bad internals in the first one to buying another one just to find out a rat chewed my wiring harness in 8 different spots causing alot of problems an the ecu somehow having melted spots in it. I decided to step back and save money up to go completely away from the electronics and go with a mtdi. Have it on now an timmed, runs great so far. I have completed my fuel system/ coolant/ an intercooler now getting ready to start on the electrical for gauges and the little bit of sensors i have in this 1992 ford ranger. So the question i have if anyone has done a mtdi swap is how do i wire up my gauges now that im using the original wiring harness from truck? Can i cut the vw connections off re pin them an just go to whatever component i have to? Kinda lost at this point with no videos an havent ran into a thread on it so any information will benefit.

 

[PickleRick]

I'm assuming you want just the tach, oil pressure and water temp gauges working?

For the tach you're going to need a signal to replicate what I'm assuming original came from the distributor of the Ford engine.

The TDI gets the tach signal from the ECU (if it's like the PD diesels).

Since you're no longer ECU controlled you'll need a new way to send the signal.

I'm not familiar with the VE TDI engines but maybe you have a crank position sensor no longer being used?

If not you could possibly use a signal from the alternator.

Now you'll need some sort of adjustable interface to take the signal from the mtdi and make it speak what the does cluster wants to see.

There are also tach pickups that clamp on one of the injection lines. I purchased one years ago to dial in a new tach for my boat, great tool for calibration purposes or permanently mount it on your dash and forget getting the cluster working.

For you oil and water gauges you just need to fit your Ford sensors to the TDI. If you need to put the coolant sensor on a coolant hose use the one coming out of the back of the head.

You'll need a pin out of your Ford cluster for feeding the tach signal but so long as you didn't back up your Ford's harness the oil and water sensors should be easy to tack down in the engine bay.

 

[Sharpshooter48]

Alright appreciate the information, i havent done any work on the electrical side of vehicles so alot of this is foreign but ill take that information an do more research. One other problem imma run into down the road is i would like to know how i need to do my turbo actuator, is there anyway of doing a manual waste gate instead of having all the vacuum lines an the n75 an the other components that go to that. This ranger has the brake booster which has to have vacuum on it to assist in braking. So i will have to think of some way to make sure thats going to work with the vw vacuum system. Thanks again

 

[burpod]

an Mtdi is a big downgrade, but to each their own.... with mtdi you're very limited , and likely have no less problems. the electrical side of the pump is pretty bulletproof

 

[PickleRick]

Did you delete the vacuum pump found on the engine?

That would be my first choice. If not, a 12v vacuum pump will be necessary for the brake booster

 

[Sharpshooter48]

the vacuum pump is still on the engine an i still have all the lines an the n75 an all the other stuff that made that system.

 

[Sharpshooter48]

so i guess my question is if i put the vacuum system in an just come off of it somewhere to the brake booster, will that work an still run the factory actuator on the turbo to?

 

[Vince Waldon]

Unfortunately, nope.

The turbo actuator is controlled (using vacuum supplied by the vacuum pump and a control solenoid known as "N75") by the engine's ECU, which takes into account various parameters from various sensors before commanding a specific boost from the turbo, monitoring that boost, and then making adjustments via the N75 solenoid.

If you've deleted the ECU you've deleted the control system for the stock turbo. You'll need to hunt down a fully mechanically-controlled replacement turbo and manifold (OEM turbo and manifold are one piece).

 

[Vince Waldon]

On a different topic, a common way to drive an electronic tach on a fully-mechanical MTDI is via a modified alternator and a converter box from Dakota Digital:

SGI-100BT: Universal Speedometer and Tachometer Interface

Dakota Digital manufactures digital instrumentation and accessories for the automotive, motorcycle and car audio enthusiast.

www.dakotadigital.com

The stock alternator has to be modified to provide the "W" signal needed by the the converter box, which requires disassembly of the alternator. Pre-TDI Volkswagens came with alternators built with this terminal, but unfortunately they are not a bolt-on replacement for a TDI engine.

 

[PickleRick]

SGI-100BT Dakota digital. Can use the W signal off of a modified alternator, timing gear or flywheel pickup.

I'd probably call them and ask if the crank sensor would produce a usable signal for your application.

 

[Sharpshooter48]

So i have a 1 1/4 coupler for my radiator hose where i had to buy a factory 90 degree hose to fit. The coupling has a 5/16 threaded hole i was going to use for the steam fitting off the back of head. If i tap a 3/8 hole for my factory coolant temp sensor will that little bit of steam affect that sensor?

 

[PickleRick]

As for the tach signal, since you're Mtdi, you can use the stock CPS which provides four pulses per revolution. Four cylinder tachs use two pulses per revolution, so you could use a V8 tach or tach adapter to halve the signal.

That should make your task a little easier. A 302 conversion was pretty popular in the ranger and bronco 2 models. You'll be able to look back and see how those guys got their tach working after the conversation.