1998 6.5 Not Starting.

[thereverend]

HELP.

MY truck is NOT starting..

I have a 1998 GMC 3500 and up till today a -10f day the truck has run and drove 100%, Now I went out to start it and NO Wait to start light is on for the glow plugs and when I go to start the truck
it turns over 1000 x but no start. I checked ALL the fuses and can not find one that is bad. There is a Service engine soon light on, on the dash but i think this was always on when you went to start the
truck just like the break light it would go out after the truck started. Does anyone have any idea on how to make this work? When it turns over it sounds like it wants to start but without glow plugs in a -10F day
I doubt that this is gonna happen. I really need to get this truck started FAST... ideas??? hints??? Please help!!!

 

[Will L.]

Do NOT use starting fluid!!! #1 fastest death to these engines.

Check for bad relay.
Check for bad fuseable link from battery to gp controller (solenoid feeding power to glow plugs mounted on top of intake manifold)

Hook up a test light to the large posts on the glow plug controller. Turn on key and see if you are getting power to it. There are 3 connections, big wires to large connector is power in, large connector with 8 small wires coming off is power out to glow plugs, the small connector with 1 wire activates it. If power is going to it but not working- disconnect ground from battery, remove controller from mounts enough to clean well then remount for the ground. I have a spare battery cable that I bypass the controller with to see if the glow plugs will heat up by connecting the 2 large contacts.

I have used hair drier after the air filter with bad gp's but it was only 20 F. idk about that cold.

Your wiring is different than my hummer so I cant help with locations.

Check back here in a while, more people will post soon that know pickup wiring and cold start issues way better than me...

 

[Burning oil]

To fix the problem move down south:hihi:

Might need new GPs. Since your wts light is not coming on it could be the GP relay or signal from ECM not making the trip.
Check the ground on pass side intake by dip stick too. Try jumping the relay like Will said that will tell you if GPs are working (if truck starts) also WTS light will come on while jumping.

 

[hookedup50]

A working block heater helps as well, but glows need to work as well. Are you getting any smoke at all out the tailpipe. Listen to all above advice, also consider raceday mechanics glow plug wiring upgrade. Best cold weather thing I did along with his battery cables. I had these issues until these upgrades.I got the -10 thing here as well and the engine starts, but have other pia issues, good luck. Look for melted wires by starter where they go by heat shield as well. Thats where my oem wiring let go.

 

[Paveltolz]

No Wait To Start Light. I had a bad connection on the orange wire from the under hood fuse box to the new GP wiring harness (my bad) that created a no WTS issue. That's the wire that sends signal to the ECM.

When you first turn on the key, you should have a slight drop in voltage readable on the meter on the dashboard.

Check the under hood fuse box for the GP fuse and ensure it's good and or clean. A blown fuse there is the same as the bad connection I had meaning no signal to the ECM. Clean the fuse contacts while you have the fuse out or just replace it.

Check for 12v at the GP controller and at the GPs. Could be the GP controller took a dump.

If you've got good fuses and 12V at the GP controller but no voltage at the GPs, Check the GP harness' fusible links about 4" from the GP Controller to confirm they haven't blown. With the key off, check for ohms/connectivity between one glow plug on each side of the motor to the connection at the GP controller. Zero Ohms means you've got a blown link.

The smoke question asked is to confirm you're getting fuel...the smoke would be heavy, very grey and smell very acrid with unburnt fuel. Your eyes will tell you as well as your nose.

Hope this helps. That cold and no start sucks. Had some issues a couple of weeks ago when temps dropped sub-zero. Hang in there.

Might as well check and confirm the block heater is working while you have the multi-meter out. If you don't hear the water roiling when plugged in, check for ohms at the plug end, there should be resistance registering and not zero.

 

[cedargrove]

Check the under hood fuse box for the GP fuse and ensure it's good and or clean. A blown fuse there is the same as the bad connection I had meaning no signal to the ECM. Clean the fuse contacts while you have the fuse out or just replace it.

On the 98, there is no fuse in the glow plug position in the under hood fuse block. I would check each side of the glow plug relay for juice first. The glow plug relay is up against the fire wall. The drivers side pole should be hot all the time. The passenger side side pole should be hot when the glow plugs would be activated.

http://i.imgur.com/IiBaNPx.jpg The bottom left picture shows the glow relay. The bottom right photo shows the fuse that was blown on my 98 that prevented my glows from working. It is not labeled as "glow plugs" though. With my fuse blown, my "Wait to Start" light would still come on in the cab, so I do not think this is your problem. The top pictures are related to the fuel pump, so no need to worry about those.

 

[Chevypoor]

I remember from reading tanman_2006 travel thread that he jumped his poles on the controller with a power of pliers. Makes sense. I have jumped the poles on the starter on a couple of old cars to get them going when the ignition switch went. Do not know though if 98 is too computerized for that trick with GP controller.

 

[JMJNet]

Check the ECM-B fuse?

I agree with everybody, in that temp, you need a good working GPs.

May want to put the Bosch GPs the next time you get a chance.

 

[Paveltolz]

On the 98, there is no fuse in the glow plug position in the under hood fuse block. I would check each side of the glow plug relay for juice first. The glow plug relay is up against the fire wall. The drivers side pole should be hot all the time. The passenger side side pole should be hot when the glow plugs would be activated.

http://i.imgur.com/IiBaNPx.jpg The bottom left picture shows the glow relay. The bottom right photo shows the fuse that was blown on my 98 that prevented my glows from working. It is not labeled as "glow plugs" though. With my fuse blown, my "Wait to Start" light would still come on in the cab, so I do not think this is your problem. The top pictures are related to the fuel pump, so no need to worry about those.

Good info to know, thanks. Good photos by the way, very helpful for a number of things.

Further inquiry on the 98 models, I was curious if the security, or pass lock I think its called, might be contributing to or compounding his issues

Haven't heard back from the good Reverend, I hope he got it sorted out.