• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Reviving a '72 145 - D-Jet questions

Joined
Aug 11, 2015
Location
Central NH
So I'm the lucky buyer on that '72 145 near the NY/Canada border. It's a '72, D-jet, and I was pleasantly surprised to find out that it's in fact a MANUAL. Woohoo!

I've worked a lot on k-jet and have my '79 running like a top, but this is my first time with a D-jet car. It ran last year per the owner and has been parked since. I'll just need to get it running enough to park on a trailer.

Planning on bringing a known good 240 battery and a jump pack, anything special I should know about D-jet to help get the car mobile?
 
So I'm the lucky buyer on that '72 145 near the NY/Canada border. It's a '72, D-jet, and I was pleasantly surprised to find out that it's in fact a MANUAL. Woohoo!

I've worked a lot on k-jet and have my '79 running like a top, but this is my first time with a D-jet car. It ran last year per the owner and has been parked since. I'll just need to get it running enough to park on a trailer.

Planning on bringing a known good 240 battery and a jump pack, anything special I should know about D-jet to help get the car mobile?

It's an open loop system, no feedback to the computer. There's a little secret knob on the side of the computer that affects overall fuel trim. I had to discover this myself, couldn't for the life of me figure out what it did. If it idles really rough, you can try adjusting this knob to see if it helps out. It can compensate for clogged or poorly flowing injectors, until you get them cleaned. If it's still running really rough, systematically remove individual spark plug wires to ensure the engine is firing on all cylinders, repeat with injector wires. Ohm test all injectors to make sure they don't have any shorts or discontinuities. I think they're supposed to be around 13-14 ohms iirc. Inspect very carefully the condition of the injector hoses. They're really prone to cracking after 40+ years, you really don't want a fuel leak right above the exhaust manifold. Gap your points if it still has points. Remove carbon build up with sandpaper if it's bad. ohm test spark plug wires to make sure they're even and in spec, I think 1.8 Kilo-ohms is somewhat normal...

A huge and extremely common occurrence is the auxiliary air valve and cold start injector having issues, whether that's CSI stuck open or leaking, AAV stuck open or cold, etc.

Using hose clamps to stop fuel flow to CSI and also stopping airflow in/out of AAV can help rule out those commonly faulty components. The car will be difficult to start when the AAV & CSI are disabled, you'll need to feather the throttle to keep it alive for the first ~30 seconds or so before it will be able to stay idling on its own.

Adjust the fuel pressure regulator with a rent-a-tool autozone fuel pressure testing kit, make sure its at 30psi (greenbook calls for 29.8 if you're extra fancy), assuming your fuel pump works. Turning the key to pos2 (maybe pos1?) should engage the fuel pump to prime and pressurize the system, this should be audible as a buzz for about half a second or so.

You can take off the valve cover and crank the engine with fuel delivery system disabled and observe the valves opening, ensure all of them are moving and opening to the same extent as the others.

Also, congratulations!!! I posted that car. How much did you snag it for?
 
The non fuel handling electrical and electronic D-jet components are pretty reliable and long term dry storage doesn't affect them much as long as no rodents have gotten a taste for the wiring. But old fuel sitting in the injectors and fuel pump can be problematic causing bad spray patterns, plugged injectors or fuel pump issues. And although not electrical, the fuel pressure regulator can suffer with old fuel too.

When it fails, the AAV usually sticks open causing a high idle and if it is a problem, you can pinch or plug 1 of the 2 AAV hoses.

You can try to start the engine with the old gas, but I am always concerned when untreated fuel sits in the gas tank for over a year so I would drain the old fuel and start with some fresh gas before attempting to start the car.

I would also try to flush out the old gas still in the fuel system by running the fuel pump for a short time with fresh gas in the tank and catching the recirculated fuel into a drain pan by disconnecting the return hose at the gas tank.

This is also a good test for the fuel pump and fuel system. You can check the fuel pressure, the residual pressure and check for fuel leaks before you try to start the car.

If you're lucky, you won't have more than 1 stuck injector as you should be able to get the car on a trailer running on only 3 cylinders.

And of course, use proper fuel handling techniques. Even old gas burns.
 
OP;
Keep me in mind if you need some "usable" '72 145 parts.
(We met up at a eEuroparts gtg a year or two ago)
 
Good news - looks like it was treated well and appears to have fresh and shiny plug wires, rotor, cap, and brand new vacuum lines. Should bode well for how things go this weekend.
 
Here's what I'll be picking up on Saturday. Guy says the windshield stuff looks to be surface rust only. Either way I'm excited!

thbPG9Il.jpg


tbCW5qNl.jpg


cYldoe5l.jpg


2NQMhZyl.jpg


EVsOcOkl.jpg
 
Congrats. He appears to have installed an aftermarket AAV that is electric rather than mechanical. Wonder if it works correctly.
Expect some crust under windshield, but it'll be alright...
 
When my rusted and bent 1800E sat around too long, the injectors tended to get stuck shut. Solution was to take them off and *gently* try to push the pintle pins upward. They usually weren't stuck in place too hard, just more than the electrics could pull. Once popped loose, they'd self clean pretty quickly once fuel started going through them.

AFAIK that knob on the side of the box only adjusts fuel trim at idle. They have a special setting just for the idle mode, triggered by contacts in the throttle switch. Once the throttle is open, that circuit is shut off and it goes into the hard-wired open-loop mode. IPD used to sell modified boxes with external fuel mixture adjustments (in a remote box) - but those didn't do anything with the idle mode, they just removed a specific resistor on the board and re-routed it through the external box, which had a rotary nob that selected resistors of varying values. And in case the box failed, a resistor you were supposed to tape to the box next to the new external wire connectors, so you could default back to normal.

That AAV looks like what A/C equipped cars had around that time frame. Although that car obviously doesn't have A/C. They were wired to come on with the compressor, and give the engine a bit more air to compensate for the added load. It's possible to wire that up through the cold start switch (on the rear passenger side of the block) which closes when the engine is cold.
 
Also, it's pretty easy to make sure the injection system is liive and the injectors are all spraying on a D-Jet. because the injectors are individually fastened to the fuel rail, you can take the whole thing off the head and lay it there, turn the key on, and then open the throttle a few times. The throttle switch isn't really a TPS (although it has an idle/throttle closed switch) - it mostly just 'fakes' some extra injector fire events - normally supplied by the switches in the distributor. As the throttle opens, a contact goes over an alternating set of printed circuits, and triggers A and B injector circuit fires. It's a funky low-tech accel enrichment function - as the throttle opens, extra injector fire events add more fuel.

Take the injectors out of their holders, turn the key on (listen for the fuel pump prime), don't crank, and then go up by the motor and open the throttle a few times. The injectors will fire in pairs, and you can just visually verify that they're all opening and spraying a vaguely equal amount of fuel.
 
You can also take a 12 V and some aligator clip wires and quickly pulsate 12V on the injectors (don't leave it on!) and listen for an audible click to ensure they aren't stuck.
 
I think they normally operate on 5V. Other than the cold start valve, that gets 12V (extra terminal on the starter --> engine temp switch on side of block --> cold start valve --> ground)

But just leave the key on, and open the throttle. If the injectors don't click then, it's likely the injection computer isn't getting power. Or the injectors are stuck. Or the throttle switch is not working right.
 
I think they normally operate on 5V. Other than the cold start valve, that gets 12V (extra terminal on the starter --> engine temp switch on side of block --> cold start valve --> ground)

But just leave the key on, and open the throttle. If the injectors don't click then, it's likely the injection computer isn't getting power. Or the injectors are stuck. Or the throttle switch is not working right.

Your way is probably a safer way of doing it, but 12V on the 5V inductors will just induce a more powerful magnetic field to open the pintle. Increased voltage will produce more heat though, which is why you don't want to leave the 12v on the injector, or pulsate them very long. I had a stuck one unstick after a few pulsations from 12V.

On John's method, the potential downside is rupturing one of several injector seals (why did they make it so complicated???) while removing the injectors.
 
That AAV looks like what A/C equipped cars had around that time frame. Although that car obviously doesn't have A/C. They were wired to come on with the compressor, and give the engine a bit more air to compensate for the added load. It's possible to wire that up through the cold start switch (on the rear passenger side of the block) which closes when the engine is cold.

It's actually an AC car! Well, it was at some point. Compressor sitting in the trunk and lines zip tied out of the way in the bay.

Got there and was able to get the car to run for a few seconds reliably on starter fluid but couldn't do more than that. Fresh battery, 5 gallons of 91 non-ethanol new gas, all fuses replaced, no dice. Looks like a dead or gummed up fuel pump. Had to winch it onto the trailer. Will take our time seeing how it goes...
 
Sometimes a few raps on the pump carrier box with a plastic or rubber hammer will get the pump going again. It helps to bypass the FP relay so the pump has power while tapping.
 
Back
Top