Glow Plug Circut

[thebrod]

Hi All

Due to my ZD30 spinning a balance shaft bearing, I have just had the engine reconditioned and fitted by a mechanic. Picked the car up on Thursday and he has replaced the glow plugs (not sure that he needed to but anyway...) and charged me $395 to "rectify non-starting problem". Now when I brought the car to him it always started fine - even with the spun bearing making a hell of a rattle! So apparently when they reinstalled the motor it didnt want to start, and they had this theory that the ECU talk module that was plugged in to the diagnostic port was confusing the computer into not activating the glow plugs..... (never was a problem before). So they unplugged it, and have fitted a light that comes on when the glow plugs are active. (allegedly this is my $395 worth). Every thing is fine when starting from cold, however when starting with a warm engine (over 70 deg) the glow plugs dont activate at all. Takes a lot of cranking to start and blows a big puff of white unburnt diesel smoke when it does. So I'm looking for clues as to why this might be the case? I rang him back first thing on Friday morning and he was going to talk to his auto sparky, but he hasn't got back to me yet.

In addition to this I had a few electrical issues today that weren't there before the engine came out and went back in. my EGT guage was going beserk when I turned the fan on or applied the brakes, and the cruise control was freaking out and throwing an ECU throttle position error code. Found a ground wire at the back of tha alternator that wasnt connected to anything. Have attached and it seems to have solved these problems, but hasn't affected the glow plug issue. Starting to loose my confidence in this engine installer....

Any advice appreciated

Adam

[4bye4]

Hard to offer anything on this as it seems to have a few issues. However it sounds to me as though there is a little problem with the engine management system (computer) which they have tried to fix with mechanical/electrical modifications. Better way in my opinion, would be to remove the mods and get a qualified person to run full diagnostics on the computer and reprogram as required.
The second part of your issues is pretty typical if you don't get all the earths connected and good connections. It may even have an effect on your hard start problem.
In a nutshell, years ago cars were just working on either battery or earth for signalling. Example, oil pressure switch was earth for no pressure, nothing for good pressure. Modern computers can be looking for a difference of .5 of a volt between good and bad signal. if you are loosing say 1 volt because of high resistance earth, your signalling and therefore your computer instructions to the engine are going to be incorrect.
Sounds as though the motor is OK, just the engine management system is not seeing what it is expecting. You could try resetting the system, but as you say the motor has been removed and refitted so I presume it has been without power for quite some time which will have reset everything anyway.

[Yendor]

Check the main earths for the ECU. Make sure both are connected and the connections are clean and tight.

They should be connected to the front of the head on the drivers side.

[thebrod]

Thanks for the replies! I have checked the main earth connections and cleaned them up and re-tightened them just to be sure. Hasn't helped the Glow plug issue tho. I have the car going back for its 1000km first service after the rebuild on next Monday and hopefully they are going to fix the glow plug issue at the same time. Fingers crossed!

Cheers

Adam

[mullet_hunter]

If it was a glow plug issue it would start when engine is warm... Similar symptoms to mine.. Hrd startn etc.. Just had mine diagnosed.. Injector pump.. Hope this ain't the case with urs otherwise ur lookn at 4k to get fixed..

[thebrod]

OMG I hope not...... Feeling especially poor after paying to get the engine recond. Can I ask who diagnosed your injector pump?

[mullet_hunter]

allied turbo and diesel.. its pretty common for people to rebuild there zd30 only for their injector pump to fail or cause there rebuilt zd30 to fail.. its recommended to rebuild both at the same time...like i said mate hope its not the case with urs.. i was shatter when they told me mine was the injection pump and the price to replace...