I melted a side terminal cranking my truck the other day.

Wow, that starter draws some current.

After seeing some discussion on the fuel relays and other things, I'm wondering if the fuel relay is hooked up correctly.

The truck has trouble starting when its cold or sitting a while.. I've chalked this up to probadly a air leak in the rubber hoses I installed during my conversion. Once the truck is warm or started, it starts fast every time.

Is there a possibility since the fuel pump is relayed off the oil pressure sensor that this is contributing to my hard starting. Maybe my wiring is wrong? if anyone has a wiring diagram for a 93, that would be appreciated. I have one that is from a computer controlled truck.


Also, the colder is it the harder it is to start. And we're only talking 60F. I've tested the glow plugs and they all are getting power, so my wiring to the glowplugs is working. I am however using the glow plug controller from the 85. I doubt this would cause a issue. Lots of cranking causes white smoke, and apparently melted terminals.

is this just a air leak? I can try jumpering the fuel relay, and opening the air relife valve and see if that helps. Any thoughts? Ideas?

Guipo

wow, it may just be glow plugs

Could my 85 controller burn out the glow plugs? I just tested them by getting my light(hooked to positive), and I touched the little piece of metal sticking out of the glow plug, and no light!!! Is it different in the 6.5's?

Are the glow plugs meant to run less than 12V? I tested the 4 on the drivers side, and no light on any of them.

I know the controller is working right, it only powers the plugs for a set time and then turns off.

As far as I know, in this engine, it worked fine before the install. And ideas?

1. Yep could be mostly glowplugs.

(I think this don't know if its true but) As a few glow plugs burn out with time the remaining good ones get more power and stress them a little so they kinda wear quicker at the end of life.

You did the test light test which basically tells you if the gp is totally open and bad but does not indicate really how good a glow plug is. You can do a second test and check resistance of each glow plug and it should be so many ohms. You have to picture it as a little heating element. How red it glows and how much glows red is important. All you know is its not open with the light test. (an ok and easy test to start diagnostics for sure).

At 60F you still need a few good gp's to start easy and idle smooth at first. Health of injectors, fuel cetane, compression health, and spinning rpm also determine a lot about startup quality.

2. How are you controlling the glow plugs again??

I don't know the logic of the different glow plug controls. But I thought the 80's 6.2's relay was more like a real controller/timer/and did the logic from the coolant temperature sensor. The 6.5 the PCM calculates the time and just sends a signal to the glow plug relay to power the GP's. I may not be doing justice to that difference. But my point is the 6.5 its just a timer relay. But the 6.2 its actually more of a controller. 2nd attempt: Something about the 6.2 it defaults to full glow time unless the coolant temp is high enough to limit glow time. The 6.5 glow plug relay has to be told how long to glow.

Also the different years the lift pump logic is different. The later years is better (more forgiving) if there is a leak after the LP because the LP powers for ~ 15 seconds to ensure prime of the filter and IP at start up while wait to start. The early 90's powered LP with key on start.

You might get some better input on the controller down in the 6.2 forum. Do you get afterglow with your setup? Small short lights of the glowplugs after startup to even combustion out until the cylinders are warm on cold start ups.

I will do the resistance test today at lunch. Question. What resistance should it read.

As to your no. 2 question, since this engine is out of a 93, it was never equiped with a ECM, PCM, etc. Or at least thats the way I understood it. It did come with its own glow plug conroller(back of the engine, drivers side), but I opted to use mine since it was already wired. I cant fathom the glow plugs burning out, cause they are hooked up to 12V, and they only turn on when the controller tells them too. I am certain of that thanks to my test light. So it may be the plugs themselves.

The previous owner did tell me that on cold mornings he'd cycle the plugs several times. I never had to do that with my 6.2, and those plugs passed the light test. This morning I cycled the plugs several times, and it started great.

So I guess I need to know what kinda resistance I should get. I think I've read that it should be 1?

oh, and to answer your question about the 6.2 relay. Mine was actually controlled by a circuit board behind the dash, which went to a doohicky on the firewall that handled the power itself. The timer was in that doohicky.

also with the possibility of the fuel leak. i know for certain that mine doesent even turn on until I get oil pressure. I wired it that way, and am thinking of running a bypass.

ok, last question. How hard is it to change glowplugs on the passenger side, where you have the turbo manifold?

Sorry I assumed it was an electronic pcm controlled 6.5 donor.

Not sure of spec on resistance you should be able to find it in a search. You could measure a few and compare numbers. If they vary a lot and have opens then I'd say too many were bad.

Not sure on how hard yours will be to change. Most do them with injectors and take off turbo, wheel, and inner fender. But your body style is different.

well I'm pretty sure they are bad, and I can get to at least 6-7 of them no problem. I dont really want to take the inner fender, cause its rusty. but if I have to I have to.

Thanks for you help, I appreciate it.

Guipo

IIRC, a good glow plug would be about .8 ohms to 1.4 ohms (NOT "K" Ohms - in otherwords, not 1,400 ohms).

Well...since we're on the subject and cold weather is approaching fast here in the midwest...is there any benefit to those fancy dancy "high powered" glow plugs offered by the sponsors?

I mean REALLY...is there a REAL, can't live without'em difference...I know what the sales literature says.

I just discovered that Heath sells some high performance glow plugs for $109 with a 4 YEAR free replacement warranty.

Man...I really like that guy.

I am just going to get some delco's, but if you look at the pics of heaths, they look like they have a much bigger contact. So they do get hotter.

I live in the valley in CA, so it dosent get colder than 45 degrees here. Only if I go to the snow.