Important Glow Plug Update !
Don't make the same mistake I did ! I installed AC 33G glowplugs, which I was always suspicious about. Prior to installation I tested them, and they really didn't get hot. One of my only functioning original glow plugs would get very hot. After installation of the AC's, and installing a manual glow plug momentary switch* ( semi-dangerous if your not careful ! ), the car still wouldn't start. After a couple of days, I got suspicious, and decided to remove the AC's, and check them. Much to my horror, #1 cylinder glow plug almost didn't come out because it had swollen dramatically. See below.
Since I had almost caused a catastrophic condition, ( swollen glow plugs, remove head, you get the idea ) I decided to never use AC 33G plugs again. I had never put power to these plugs for more than 10 seconds, and I had never sprayed the engine with starting fluid when I knew the plugs might have been hot or warm. The only explanation for the tips swelling would have been power to them for too long a period, which I don't understand. Since the things never got hot anyway ( I tested them prior to installation ), these things were absolutely useless.
I have since installed some different glow plugs manufactured by Beck-Arnley upon some excellent advice given to me by Mr. Matthew Patterson:
Bob,
During my 16 years now of owning my old I-Mark I have only replaced 2 glow plugs so I
still have 2 of the originals in there. Mine does not have a block heater so I can't
help you with that part. I have always used Beck - Arnley glow plugs I can't
remember the exact number but I probably have a set out in the garage waiting for mine to
burn out. During all of the years I have owned this I have only had trouble starting
it one time and it was - 15. I was in the western north carolina mountains and I got
a frien to hook his truck up to me to help my battery turn it a little and it finally
started up. Both of mine are excellent cold weather starters. I know that
doesn't help you though. I would try some Beck - Arnley glow plugs and check the
injection timing you would be amazed at how much effect this will have on the starting of
the engine. Also the bar that runs between the glow plugs you should take it off and
sand the contacts I have had to do this a couple of times. ! If one place is corroded the
other plugs will get all of the power and burn them up and the thing still will not start.
Check the bar, check the ignition timing, get some Beck - Arnley glow plugs and of
course when all else fails fix the block heater.
Let me know how things turn out.
Matthew Patterson
North Carolina State University
**********************
Mr. Patterson had been giving me advice since I purchased this car, and it has been invaluable ! He has a lot of knowledge concerning this Isuzu engine. He owns a couple of I-Mark autos, and has driven Diesel cars since forever.
I tested these prior to installation, and after only four seconds, these plugs were glowing red hot ! After installation, the car started instantaneously, something it had never done previously. Although it was 60° at the time, it had never started well previously even when it was warmer.
The part number for these excellent glowplugs is: Beck-Arnley 176-1043. USE THEM !
Update
As my glowplug relay system is still non-operational, and probably will be for some time, I am "mimicking" the factory starting procedure as given to me by Mr. Patterson. Power the plugs for 4-6 seconds, depending on ambient temperature, then after starting the engine, give them a couple of bursts of power every couple of seconds. When the temp drops below 30°, the engine starts and runs quite nicely using this procedure. After about 10 seconds of this, the engine will run on it's own. As I am not using this car during cold weather, I am not using the factory block heater which would probably help even more. Both of my Diesel Chevette's are equipped with this "system", and will probably always be like this as I like it.
* A momentary switch is simply a switch that supplies power when you're pressing it. When you stop pressing it, no power is provided, unlike a toggle switch that must be flipped one way or the other.