760 V6 getting closer to scrapyard...help!

[russwinchester]

Latest update, I've cleaned up the dizzy cap and rotor arm contacts, checked and cleaned fuses, tried the oil down the bores trick and still nothing (cranked for a good long time and tried throttle blip, no difference). Reading all the helpful advice on this thread I did notice the spring pressure was a bit weedy in the dizzy cap, so I might buy a new one.

I have managed to destroy two HT leads in the process of trial and error so I'll be looking out for a new set.

I can see the EZK now, so thanks for the directions! I'll try the ignition parts first then potentially try and find someone who has a 760 EZK (0280 001 505) they might be able to loan me before I throw too much more cash down the drain

[Laird Scooby]

Originally Posted by russwinchester

Latest update, I've cleaned up the dizzy cap and rotor arm contacts, checked and cleaned fuses, tried the oil down the bores trick and still nothing (cranked for a good long time and tried throttle blip, no difference). Reading all the helpful advice on this thread I did notice the spring pressure was a bit weedy in the dizzy cap, so I might buy a new one.

I have managed to destroy two HT leads in the process of trial and error so I'll be looking out for a new set.

I can see the EZK now, so thanks for the directions! I'll try the ignition parts first then potentially try and find someone who has a 760 EZK (0280 001 505) they might be able to loan me before I throw too much more cash down the drain

Not even a cough or splutter as if it was trying to start?

Silly question, but are the HT leads on correctly? Cylinder numbering is from rear left going forwards 1-2-3, rear right going forwards 4-5-6. Usually on the dizzy cap there are markings for the cylinder numbers and the firing order is 1-6-3-5-2-4. I'll try and get a pic of mine shortly to give you some sort of reference to go on.

Also are you sure that despite opening, the injectors are actually injecting fuel? If you pulled a plug after the start attempts you should have found it wet. Chances are they will have dried by now.

I think i may have a fuel ECU, i'll need to check my stash.

[russwinchester]

When I put the sensor on the lead, there was a tiny flutter and there must have been some back pressure as the exhaust popped slightly. After this, no joy.

The plugs are wet and sooted up quick, which I assume is due to regular flooding now!

A pic would be really useful of the lead routing just in case, but the leads are all certain lengths so I imagine it would be hard to route them incorrectly....but this car never fails to surprise.

Also a pic of your spark sensor installation on the lead would be useful, just to check I installed it right (not sure if there is a direction it needs to be pointing as one end of the sensor plug lead "tube" is chamfered).

For the sake of £30ish I will order a new dizzy cap and check leads and firing order...

[Laird Scooby]

Pics as promised!

Dizzy cap - central lead is king lead to coil :



Left hand end as views is #3 lead ^^^^^

Right hand bank :



I'll try and add some notes actually on the images.

*** EDIT ***

I tried drawing pretty lines on the plug leads to show i'd followed it but somehow managed to lose the images in my PC but before i did i made a note of what plug leads go where on the dizzy cap.

From left to right AS VIEWED it is :

3___5___2___4
__6___C___1

Hope that makes sense!

[russwinchester]

That made perfect sense, thank you for your time and effort and sorry you fell victim to the computer, sounds like my work life most days.

Unfortunately the leads were hooked up correctly in my car

So I've ordered the dizzy cap from parts monster and we'll see where that gets me.

I'm also getting some custom HT leads made up at a local ignition specialist with the sensor in line, so fingers crossed....before I have to call a mobile mechanic who can diagnose better than me (not difficult).

[Laird Scooby]

Originally Posted by russwinchester

That made perfect sense, thank you for your time and effort and sorry you fell victim to the computer, sounds like my work life most days.

Unfortunately the leads were hooked up correctly in my car

So I've ordered the dizzy cap from parts monster and we'll see where that gets me.

I'm also getting some custom HT leads made up at a local ignition specialist with the sensor in line, so fingers crossed....before I have to call a mobile mechanic who can diagnose better than me (not difficult).

You're welcome, i found 2 out of the 3 images i'd altered but to be honest the best information was on the last (lost) image as it showed the dizzy cap and the numbers i'd added on.

Will be interested in seeing pics of the leads you're getting made up, they do know the dizzy cap has M4 terminals in and not the standard HT terminals? When i was going to build a set of leads, i found just the cost of the M4 terminals to go on the leads made it unviable against the cost of a ready-made set, never mind the additional cost of the cable itself.

Out of interest and on a slight hunch, have you tried using Easystart on it since you got the car home? If only to prove the point as to whether it's capable of running as that should prove the ignition side of things too.

[mister grimsdale]

This may be a complete red herring, but I had a similarly mysterious problem many years ago, not on a Volvo but on an MG. Symptom was a sudden and complete loss of power whilst driving -- didn't even cough. The culprit was the rotor arm, which had no visible defects but I can only assume it must have developed an internal short to the distributor shaft. No amount of cleaning and sanding made any difference, but replacement cured the problem immediately. Worth a check?

Phil

[Laird Scooby]

Originally Posted by mister grimsdale

This may be a complete red herring, but I had a similarly mysterious problem many years ago, not on a Volvo but on an MG. Symptom was a sudden and complete loss of power whilst driving -- didn't even cough. The culprit was the rotor arm, which had no visible defects but I can only assume it must have developed an internal short to the distributor shaft. No amount of cleaning and sanding made any difference, but replacement cured the problem immediately. Worth a check?

Phil

I'm pretty sure he's got a new rotor arm and dizzy cap on order so we'll soon know. Can't help wondering about the HT leads, i've had sudden and complete failure of a set of HT leads on my other beast, not known it on any other car but that doesn't mean it couldn't happen.

Not sure how helpful this will be but just bought one of these myself :

https://www.ebay.co.uk/itm/313578728044

As pointed out in the listing, it's a new ebay account for an established seller and one i've used many times with no problems.

[russwinchester]

So, new dizzy cap arrived today (didn’t replace rotor as it looked good) so reading the post above makes me suspicious 🤨

No change again😩

I keep going back to the fact that I heard it running on easy start when I bought it, then once I started replacing stuff, now it doesn’t.

When I reflect, the first thing I replaced was the Crank Sensor…now this part was sourced from an auto factor near me. It cost £12.50 which seemed a bit too cheap and was all black plastic rather than the metal one I took out, however I went with it, and it does seem to be sensing a signal when the engine cranks and I hook it up to a multimeter.

I destroyed the old sensor wrestling it out, took hours of wrestling.

I might go and get a better quality one. Any recommendations?

[Laird Scooby]

Originally Posted by russwinchester

So, new dizzy cap arrived today (didn’t replace rotor as it looked good) so reading the post above makes me suspicious 🤨

I keep going back to the fact that I heard it running on easy start when I bought it, then once I started replacing stuff now it doesn’t.

The first thing I replaced was the Crank Sensor…now this part was sourced from an auto factor near me. It cost £12.50 which seemed a bit too cheap and was all black plastic rather than the metal one I took out, however I went with it, and it does seem to be sensing a signal when the engine cranks and I hook it up to a multimeter.

I destroyed the old sensor wrestling it out, took hours of wrestling.

I might go and get a better quality one. Any recommendations?

Most CPSs are plastic these days to prevent you having to wrestle them out. What make/part number was the one you fitted? The price sounds good, not especially cheap but a Bentley owner would be glad to pay that little for it instead of a few hundred!

Have you checked the fuel pump relay hasn't come loose in its mounting? I have a modified one that can be externally switched to operate the pumps regardless, have you tried it on Easystart since?