What does the fix involve Eleki Doc ?

Do you replace the whole loom and where is the connector situated please ?

Actions so far:

I might have said above - renewed fuel filter.

Rough clean of EGR, as it was over 1/2 diameter clogged. This seemed to make a noticeable improvement. The car seemed more responsive, however under load (up hills) especially under 2100 rpm it still got lumpy and lost power. Very carefully I am able to drive at 65 + mph, as long as I'm gentle on the throttle, and accept that hills will quickly drop to 55mph in 4th

Today: removed, cleaned (scraped, burnt out and pressure-washed) the inlet manifold. Better job on EGR. this time found the EGR valve was not opening properly, and manged to free it off, giving full travel (sucking on tube and pushing at the same time)

Improved again, however basic symptom is still there.

I have just studied how the vacuum system works. Very soon I will check it is correctly connected, then I expect to renew most of the pipes, and see if I can check the solenoid valves.

One odd feature is that if I constantly change the throttle just a little, it seems to put off the the symptoms, conversely even gently powering up a hill will induce them. I wonder whether there is a reason, maybe as the throttle is being opened, things are satisfactory, but when it is constant (under load) there is an issue with the mixture (air I assume - but possibly the fuel)

Still I drive it everyday 25 miles each way to work, and try to stay under 65, except for down hills! or a tad slower on the way home. Off to Bristol tomorrow, from London!

I haven't done a thing about the wiring loom. My thought is "how can such described poor electrical connections, be dependent on engine revs and load? Why wouldn't it be random, and generally increasing?"

.

This would seem to go against a vacuum leak as the cause of your symptoms, though a fuel leak might be a more likely possibility

On a pd engine there is a vacuum take off from a T piece in the brake servo pipe with vacuum generated by the tandem fuel & vacuum pump at the end of the cam shaft. There is then a load of plastic & rubber pipes that then go onto control solenoids that operate EGR, variable vanes on the turbo & anti shudder valve that can leak/fail and cause problems. Usually it'll log a fault and go into limp home mode and remain that way until restarted - on mine that meant no power up hill - but it wasn't shaking. Start from the servo T connector and check every rigid and flexible pipe.

However as it's a common fail and easy cheap to do the unit injector wiring loom is a good call anyway. It usually to start with intermittently drops a cylinder which would give lower power and an engine shake. (Round connector at the end of the cylinder head.)

Any error codes logged? Any new noise from the engine?

Edited by Big John on 10/05/2023 at 13:44

Thankyou for all your help.

Last weekend I finally "did" the injector wiring loom. Stupidly I didn't order a new one first! I took the old one out, tightened the plugs, and put it back. Bingo!

Don't waste your time on this its a pain! Its annoying, fiddly and time consuming. I ended up with some broken plastic plug enclosures.

The engine problem seems solved.

I also checked the vacuum hoses, and all are routed correctly, and not obviously damaged.

Gave her an oil change last night. Sounding quite good.

So Thankyou all.

However - 1 - I'm a bit suspicious that managing quite a bit of driving before finally fixing the injector wiring, may have worn something possibly the No4 big end.... due to slap form missing... I had an extra small but "hard" knock at times before fixing....

So If anyone is reading this for advice - Replace the injector wiring loom, its dead easy. The only annoying bit is taking the EGR off to get at one of the rocker cover bolts!

Thankyou "elec and ac doctor" for your reply on the 28th February. I should have followed your advice THEN. you were right!

But really in ONE go Clean (or replace the EGR and inlet manifold, (if they need it ) AND do the injector loom! And it will feel like a new(er) engine!

That should be the end of it however I now have a gearbox or diff problem now due I think to a stupid accident!

Edited by Sailor on 29/06/2023 at 20:32