240 General: '89 240 KJet Issues

[Big 240]

This threads perfect for me right now as I am having a similar issue.

I recently replaced the in-tank pump (as it appears to have been dead for a while) and since then have been chasing a starting issue.

Up to date I have done similar to the OP, I've also replaced the faulty fuel pump relay, checked both pumps run and that fuel is getting delivered to the engine. Coil has life and spark.

It has new plugs (awaiting delivery of dizzy cap and rotor) as the current cap has a couple of crusty lead holes (cleaned out as best I can)

Engine just turns over, has nearly started once. But not jumping into any kind of life yet.

So I have read up on the AAV and that this can get stuck closed, which can cause non start issues.So I removed and cleaned out and it does appear to be stuck on almost closed. I can open it freely with a screwdriver, so I know it's not jammed and I've given it a good clean with carb cleaner etc. I had it attached to 12v for a few minutes but it only seemed to slowly close up further???

Is there anything else I should be checking? I did have a little play with the CO2 screw, I did a couple of quarter turns to lean it out (no joy) as I am thinking if the in-tank pump has been dead for a while then this might have been played with to help running etc.

[morsing]

Originally Posted by Big 240

So I have read up on the AAV and that this can get stuck closed, which can cause non start issues.So I removed and cleaned out and it does appear to be stuck on almost closed. I can open it freely with a screwdriver, so I know it's not jammed and I've given it a good clean with carb cleaner etc. I had it attached to 12v for a few minutes but it only seemed to slowly close up further???

That's about right for current temperatures (assuming you're in the UK). Put it in the freezer and see what happens.

The AAV is just like opening the throttle a little anyway, so if you push the pedal down a bit, it will have the same effect. Have you checked your cold-start injector is firing?

Not sure why people think the pre-pump failing will make the car run rich or not at all. The fuel-distributor has pressure regulator and the main pump is plenty powerful for running the car.

Henrik

[Juular]

Step one, bridge fuses 4 and 6. You should hear the main fuel pump running.

Next, put the Allen key into the CO screw at a slight angle and use it to lift the whole plate. This should dump some fuel in the cylinders and you should be able to hear the injectors whistle clearly. Don't do it for too long as you don't want to flood it or dilute the oil.

Now that there's some fuel in the bores try starting it.

Let us know how that goes.

[Big 240]

Thanks Henrik and Juular, as I'm still learning my way round these cars I appreciate the help. With regards testing the cold start injector, is it a case of removal and putting in a jar and checking it squirts when engine cranked?

Juular, I know the main pump is working, is your suggestion just to ensure the pressure is good, it's not to have it running continuosly?

[morsing]

Originally Posted by Big 240

Thanks Henrik and Juular, as I'm still learning my way round these cars I appreciate the help. With regards testing the cold start injector, is it a case of removal and putting in a jar and checking it squirts when engine cranked?

Just put it on top of the inlet manifold and turn the starter for a second. You should see a spray from the injector. It won't be a lot, but stack a towel in front of it if you don't want it going anywhere.

[Juular]

Originally Posted by Big 240

Thanks Henrik and Juular, as I'm still learning my way round these cars I appreciate the help. With regards testing the cold start injector, is it a case of removal and putting in a jar and checking it squirts when engine cranked?

Juular, I know the main pump is working, is your suggestion just to ensure the pressure is good, it's not to have it running continuosly?

It will rule out whether fuel is able to reach the injectors and that the control pressure isn't mega high due to a blockage.

If it starts it also rules out the ignition and points back at probably the warmup regulator or main pressure regulator.

It also bypasses the fuel pump relay and wiring.

For all Kjet diagnosis you have to run the pump continuously but you don't want it that way when using the car normally

[Big 240]

OK guys quick update.

I have fitted new rotor arm and dizzy cap. After a period of starting instantly then stalling, this happened approx 5 times. I was leaving it a little bit in-between tries. On the sixth attempt it started perfectly, so I let it sit idling up to temp, all good in da hood.

Happy days.

The idle is a little high now (approx 1300rpm) so once I've settled that down I think that's sorted it.

I will still go over the engine to check and observe, but at least this can be done knowing it's running well again.

[Bugjam1999]

Originally Posted by morsing

Not sure why people think the pre-pump failing will make the car run rich or not at all. The fuel-distributor has pressure regulator and the main pump is plenty powerful for running the car.

Henrik

My car (when it was standard with k-jet) needed towing home after the in tank pump failed- based on that I’d be very surprised if a k-jet car would run on just the main pump, although I’ve heard they’ll run if the tank is between full and 3/4 of a tank.

Easy to test I suppose, with a running car just pull the fuse for the in tank pump and see what happens.

Cheers