GP Controller

[datkinsonsr]

I'm not sure if this has been talked about before or not. The first on cycle runs the normal length of time and then the Wait to Start light goes out. The second on cycle, no light and the relay cycles on, off, on, off, repeatedly. My voltage gauge (after market) cycles from 10 to 13 volts along with the controller relay. This is on a cold engine, and when it first began the air temp was 38 deg. The engine will start during the second cycle and the voltage is still jumping 10 to 14 volts for several seconds after the engine is running and settles in at 14 volts. I have never been into any of the glow plugs, and do not know their history. I'm right at about 190,000 miles.

Any ideas on this one?

 

[Headerpower]

Sounds normal; Glow plugs cold have very little resistance, the controller cycles until they get up to temp from the combustion heat. Once warm they have 15-20 ohm resistance, the controller quits cycling.

 

[datkinsonsr]

GP Controller.

The Wait To Start light no longer comes on during the second cycle, or any other after the first. It has never worked this way before.
On Edit: this cycling is very, very rapid after the first try.

 

[93_E_350]

I don’t know how close the two years are but check the *Glow Plug and Controller Analysis 1993 document I have on my web site, I think the check out procedure might be the same. It’s in pdf format but it’s easer to follow if you can print it out - 18 pages.

*Look under “Diesel Information”, then click on Glow Plug and Controller Analysis 1993.

93

 

[datkinsonsr]

Thanks for all the input. Now to get in there and find it.

 

[zigg]

Sounds like it's working normally. IF one glow plug is burned out, the 1st cycle time will be shorter, and it'll likely lope at first when it starts.

The second cycle time is meant to be on/off. This is the warm up cycle, and it is meant to reduce cold engine startup white smoke, till enough combustion heat is produced...

Zigg

 

[datkinsonsr]

Quick update: I pulled all glow plugs, all are Beru's, 2 were bad (No continuity). Installed two new Beru's and all is well. Thanks for all the help, everyone!