Need some advice on a hard starting CUCV

[DrFoster]

Hey guys! It has been a while since I've had to post - just because I haven't had anything to add in the recent months. I have ran across a problem that needs some advice.

This rig is an 84-ish 6.2L diesel with 61K on the odometer. The problem is that it cranks without starting when just cold, around 50-75 degrees for a long time. It hardly wants to start below 40, taking the beter part of half an hour of cycling / heating / cranking.

I'm trying to think of the best way to resolve this before winter strikes in full swing.

Is it glow plugs or a controller? When I try to heat the plugs, it takes about 60 seconds for the wait light to go out, then if I repeat the steps three times more, it struggles to start in the 50-70 degree range. If it is colder, it just takes tons of cranking (about 45 seconds worth) combined with 3-4 heating cycles wearing both the batteries, cables, starter and other associated equipment.

Once it does get going, it only takes 5 seconds of cranking to start it.

Thanks for any help!

 

[CCATLETT1984]

sounds like the controller card is bad.
you can hook up a manual switch very easy.

pull the light blue wire off of the small terminal on the gp relay under the hood. run a wire from it to a heavy duty momentary on switch and ground the other side of the switch.

also once the temps drop below 30 you will want to plug in the block heater, it fits in one of the freeze plug holes, should be installed on the drivers side of the engine.

 

[doghead]

Check your resistors or resupply the solenoid with 12 volts from one battery if you do modify it with a manual push button. Many times it seems that the controller goes bad because one of the 2 resistors fails(sending 24v instead of 12v to the controller and glow plugs).

 

[acetomatoco]

put in a set of glowplugs and a manual switch and eliminate the resistor pack on the firewall and hook em up direct to the red 12V feed and vrooom vrooom and away you go. All you have to do is count to 10, do it twice if below 10 degrees or so... Secondly, be sure that the oring under the fuel pressure switch is good and not letting fuel drain back requiring repriming every time you crank...

 

[Michael]

mine did this when i had burned out some but not all of my glow plugs.

 

[DrFoster]

Again, thanks, I'll look into it and provide feedback here.

 

[isaiah]

my 1028A has a problem with starting also, while the weather here averages only about the 80's my wait/glow light seldom and never goes on I pump the gas pedal and it starts up with at least two tries. I am concerned about the wait light not going on, however I do wait at least 10 seconds in the on position before cranking.
Is my glow plugs bad or controller card? and like the DrFoster said "once it does get going it takes only 5 sec (or less)cranking
to start."

 

[CCATLETT1984]

isaiah you have a bad glow plug temp sensor, its stuck in the open position (the truck always thinks the engine is warm enough not to need the plugs.) I always get confused if its the temp sender on the front of the drivers head or in the rear. I'm sure mike will chime in with the correct location. you can jumper the two terminals with a piece of wire to see if that is the problem.

when you turn the key to the on position, do you hear a click? coming from under the hood (that is the glow plug relay cycling on. If you hear that, its the temp sender.

 

[isaiah]

Ccatlet yes i do hear the click, it does it couple of times then it stops, so how do i get and change a temp sender/sensor?

 

[isaiah]

ccatlet saw your pics on photobucket and notice one guy doing the "shaka" hang loose sign. where did you get that impact wrench? and nice setup on your truck and awesome bunch of MV'S!

 

[CUCVFAN]

The temp sender for the GPs is in the rear drivers side. Have you ever pulled the GPs? If the relay is cycling, then it should be sending power to the GPs. Check for voltage at the input to the relay (from the firewall resistor).

 

[CCATLETT1984]

Re: RE: Need some advice on a hard starting CUCV

ccatlet saw your pics on photobucket and notice one guy doing the "shaka" hang loose sign. where did you get that impact wrench? and nice setup on your truck and awesome bunch of MV'S!

that goofy guy, is gimpyrobb.

I got the impact off of ebay, they are on there every once in a while. They are called RoboImpacts. Be prepared to spend ~$150 for a working one. Parts are still readily available for them. the brushes are the most common thing to go (of course). It works GREAT!!!

 

[ARMYMAN30YearsPlus]

RE: Re: RE: Need some advice on a hard starting CUCV

Either is my friend...

 

[Manstein]

Be careful using ether on a 6.2. Something will bust. I work for a Chevy dealer and did thru the 80's when those things were everywhere. It's either a bad controller or the civilian models had a glow plug inhibit switch. It was basically a coolant temp sensor that told the controller to cycle. The problem with bypassing the controller is that you will never cycle the glow plugs too long but sooner or later someone else who doesn't know the trick will melt them. Try to fix it first.

 

[mangus580]

do NOT.... again, do NOT use ether on a 6.2..... do yourself a favor, finda can of pure silicone spray, and use that instead. Its glow plug friendly.

I would suggest wiring up a temporary manual button, for testing purposes. This will tell you if its a bad controlelr or not. I think quite often, a controller is misdiagnosed, due to bad plugs themselves....