Glow Plug HELP!! not the usual culprit either
 

ok, i have a stancor gpr with an led light wired to it to see exactly how long the glow plugs stay energized. here recently in some very cold temps, when my glow plugs should have been staying on for 30 seconds to one minute or more, it has started coming on for only about 10-15 seconds and then going out causing some very hard starts with lots of white smoke, never got that before. maybe a puff or two, but now i get a cloud of it. thinking the only thing it could be was a bad relay, i ordered a new stancor replacement gpr and installed it. same thing still happening. on 20-30 degree nights with engine dead cold, gp's only stay on for 10-15 seconds at best.

anyone else had this problem and if so what fixed it? what drives the timing of the gpr staying energized? i heard it was ambient air temp+oil temp+baro pressure? i also checked all of those and they seemed to be reading fine, at normal operating temps. any ideas on what to do next? any help or advice would be much appreciated.

Sounds like your old GPR may not be bad. Does this help?

Welcome to guzzle's White-Rodgers (Stancor) GPR replacement Mod Web Page

yes im going to check the actual voltage this afternoon or tomorrow after it has sat for a bit and will certainly be calling for gp's. bob is the one that was telling me about the formula for gp timing.

See if this helps.


https://cimg9.ibsrv.net/gimg/www.for...e3ec287ed4.jpg

Bob is one of the best to talk to on so many 7.3 issues.

Block heater not plugged in?

thats a great chart andy, thanks! i will use this pm and try to get to the bottom of this. certainly frustrating.

Yes Les, Bob really seems to know his stuff!

hopefully just a bad EOT sensor and not a PCM baro problem. but if i read your chart correctly andy, pcm baro reading would only affect timing by 5 secs +/-??

based on the chart, mine should be staying on 110+ secs, and it might be on for 10-15 tops

block heater not plugged in correct. if block heater is plugged in all is fine. i just hate using it, and really have never had to until now very suddenly. also the acute onset of this problem is what has me kind of baffled.