'87 240 Spark, No fuel

Denied72 · 2024-09-11T10:52:19+00:00

Heyo, i'm at my wits end and need a bit of help Just put my engine in with a new ignition harness and for the life of me I can't get it to get fuel to the e...

Denied72

ramrod Yeah everything was labelled on the new harness so the main stuff should all be right. I'll have another look this arvo I guess.

Denied72

Ok so, currently I have no fuel pump and no injector pulse. I've tried

Testing continuity over breaker in place of the underhood fuse, its fine, continuity achieved when installed in the housing
Testing both in tank and main pump with fuse jumping, both work
moving grounds around on for the injector and hall sensor, nothing changed,
swapping ignition ecus, no change
swapping fuel ecus, no change
manually pushing the fuel relays together. Had it working for a bit but has now stopped.

Car still does not get fuel into the cylinder. not sure what to check next. Very stumped, would love help because the car is meant to be out of the driveway this weekend.

Denied72

I've also got this random brown cable coming out of the part of the harness that goes to the dizzy.

I've got no male blade connectors left to plug it into and it can't reach any other wires.

Not sure if it's important or not.

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ramrod

That’s the knock sensor wire.

Or is there another wire already connected to the knock sensor?

Where abouts are you from? If local to Sydney I could supply a new fuel pump relay because it seems like you need a new one

Denied72

ramrod I'm in Wollongong, so not quite local to Syd. These relays are too old to be available off the shelf at your jaycars and etc right?

jamesinc

Knock sensor is a two pin plug. It could be a switched 12V for diagnostics, similar to the blue connector on the firewall harness that you use for triggering the starter. Probe it and see?

Denied72

jamesinc yeah it's not something that's on the old harness so not quite sure. I'll be tracing everything to the diagram over the weekend and hopefully I'll find something.

ramrod

jamesinc

Not on LH2.2

That system uses a single pin sensor unlike LH2.4 which has two pins thus two wires

jamesinc

ramrod the one wire knock sensor is a Chrysler ignition thing easier than LH-2.2. IDK if there are 240s with LH-2.2 for fuel and Chrysler for ignition, but there are definitely LH-2.2 cars with two wire knock sensors

ramrod

I have two LH2.2 cars here at the moment.

Both have only one wire on the knock sensors

jamesinc

🤷🏻‍♂️ I've owned two LH-2.2 cars and both had two wire knock sensors. I don't think its the LH system that dictates it, it's the ignition system (EZK, Chrysler, etc)

ramrod

jamesinc

Were they turbo? If so then that would be right.

The turbo cars had the EZ116 and 117K ignition ECU.

Thus no need for the engine compartment control box that the non turbo cars came with. And the turbo cars did have the later two pin knock sensor.

Both the cars here are non turbo.

Denied72

Alright, update.

After tracing the whole fuelling harness back to the wiring diagram and having 12V and grounds everywhere they needed to be on the LH2.2 ECU and fuel relay. I connected the knock sensor, no luck, but then swapped the ignition computer and had her fire up.

From the wiring diagram, not quite sure how the ICU could have caused problems with fueling while having the spark working but I'm not going to complain about it working now.

Time to throw her all back together and hope that plugging in the intake + exhaust sensors will sort out her wanting to idle at 2000 rpm.

ramrod

By ignition computer, are you describing the unit located in the front right of the engine?

Never seen one fail, either the unit itself or the wiring harness to it.

You may have got it to work by moving parts of the wiring around, but, you might still have intermittent problems. Time spent driving the car will determine if it’s going to be reliable

Denied72

Yeah, the one on the right fender. Could be a short somewhere, however the harness is brand new and nothing has changed with the fueling harness so, if it was a short, it'd have shown up prior with the old harness I'd imagine, or we would have seen it when we were probing around.

Hoping that it was the ICU so I don't have to go through the headache again.

timbo

Denied72 I've worked on Volvo's for nearly 20 years and have seen those ignition modules fail a couple of times but not very common

Denied72

timbo I think this car just likes causing me pain. Thats my only explanation

Denied72

So, after getting the whole car together and attempting a test drive, it made it down the driveway before hitting its first bump and shutting off. Looks like @ramrod was right about where the failure was, and I will now be spending the next weekend tearing my hair out trying to find the fault. I love this car

She also doesn't want to run without the AMM disconnected but that's a bridge to cross once the harness is actually happy to work reliably

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