I may be buying a car with a dead fuel injection system.

I've got a spare intake manifold and SU carb setup. What

else would I need to make this work? Should I just put a fuel

pressure regulator on the existing fuel system or should I

run a long fuel hose under the car from the gas tank and attach

a mechanical fuel pump? I mostly want to get the car running

so that I can get it home under its own power as a tow would

be expensive at the distances I'll need to move it.

This is for a B20 equiped motor, BTW.

Thanks,

chris

Why don't you try to get the F.I working before you convert it? If I'm not mistaken, don't you have at least one other D-jet car around that you can swap parts between for trouble shooting?

Well, I've got access to a 73 142 that has a mostly intact

FI system -- I have my doubts about the vacuum sensor thingy

but otherwise I think it is good (except too may of the wires

are rotted out and the car's suspension is shot and so on).

The big problem is that the car I've got is several hundred

miles from the other car, so I'll have to guess correctly

all the parts I'll need to bring with me to make the thing

work. I was going to bring with me:

Will a mechanical fuel pump work with the FI fuel filter

or will I want to bypass that as well?

SU manifold / carbs

mechanical fuel pump & gaskets & spacers

fuel hoses

FI controller

fuel pump

fuel filter

wires & tape & paint on insulator

distributor & coil

First thing is see if there is anything obvious broken, then

check the points, then swap the FI controller, then make sure

the injectors are firing, then clean the throttle contacts, then

short the block temp sensor, then give up and disconnect the

fuel pump, bypass it, install the mechanical fuel pump, and

replace the intake manifold.

Of course, I'll only do this if the car has good compression,

spark, and the valves all open (and close).

seem reasonable?

chris

"...I have my doubts about the vacuum sensor thingy..."

Unfortunately, that's a part known for failure at old age, and one of the pieces you would want to have along with you on the "rescue mission". BTW, it's called a Manifold Air Pressure (MAP) sensor.

If you suck on the hose which is connected to it, you should be able to pull the diaphragm down without any continual leaking. If it passes this high-tech test, there's a very good chance it's still OK.

John's trouble shooting suggestions are excellent. I think he feels like I do that you should do everything you can to retain the D-jet. If you have to throw a carb system on to get the car home, don't do anything to render the F.I. system unrestorable. I'd have to think in the long run you'd be sorry. Good Luck!!

Its rare that d-jet won't run at all. It usually just runs poorly when components fail.

It could be as simple as a lack of power supply to the FI system - a fuse or bad relay. When you turn on the key you should first hear the pump whir for a couple of seconds, then with the key still on while pressing the accelerator down you should hear the injectors clicking (you might need to under the hood to hear them if it is noisy). If you don't hear these things suspect the power supply.

Next, loosen all 4 injector collars, twist the injectors slightly to break the stiction, and pull off the fuel rail with all wires attached. With the key on (actually, turn the key on and off several times to ensure good fuel pressure) go under the hood and press the acclerator slowly - the injectors should fire in pairs. If one doesn't swap places with one that does to isolate a wiring vs. injector problem. If an injector doesn't spritz you might try pushing the pin in at the tip to break loose any gunk. In addition to your above parts you might want to include the fuel rail and all 4 injectors from your other car - it easy to pull off and replace.

If they all spritz the final test is to look at them while the engine is cranked. If they don't spritz then look at the distributor trigger contacts. If they do then as a last thing check the fuel pressure - I think 28 psi is correct. Just pull the hose off the cold start valve and hook it to a gauge. The regulator is the big silver gadget either on the fuel rail or on the firewall. Those can stick and throw the pressure off.

Assuming all those quick shade tree tests work the car should run, although if the pressure sensor or one of the temp sensors is bad it may run poorly. For fine tuning refer to this D-jet site I found once:

http://www.icbm.org/erkson/ttt/engine/fuel_injection/d-jet.html

Good Luck, John Mc

Getting gas to the carbs is the biggest problem.

You could probably bypass the electric pump and get it to

work with the standard pump on the side of the block

(just take off the plate and mount the pump - DON'T forget

the plastic spacer, though - it's important!)

Use the aluminum intake manifold.

I'd suggest that you leave the FI system as intact as you can,

because it is a great system if you can get it to work.

Better performance, etc.

A fuel pressure regulator probably won't handle the pressure the

Bosch pump puts out - especially since the bypass FI regulator

won't be there to help. The electric pump can put up more than

100 psi so you need to bypass a lot of fuel to get the pressure

down to where you can use it. You might be able to do a hybrid deal

with the bypass pressure regulator loosened up as low as it will go

and then a regular fuel pressure regulator after that. BTW the

fancy chrome fuel pressure regulator I put on my 122 started dumping

large volumes of gas over my engine the other day. Fortunately I had

hooked it up with plenty of hose so I just took it out and re-did the

hose to the back carb. Working OK now.

How hard would it be to bypass the fuel pump system at the

fuel tank? I think I can preserve most of the FI system intact

mostly, and repair it later when I have the car back at my house.

chris

I think it is about 3/8" hose. Since you aren't using the

pump, soft, low pressure hose will work fine.

Hope your tank isn't too full........