I had some hard starts this winter, so I decided to check the GP system and everthing checked ut fine. All teh GP's were testing good, but hte truck would struggle to start. I decided to replace a bang of my gps. When I removed them the element end was coated in a black baked on stuff. What is that, and is there an addative to deal with that? The reason I ask is I did GP's last winter and again this winter, I dont want to make it a yearly event!

Thanks!

 

What type of Glowplugs are you replacing them with? You should be using motorcraft ZD-11. All the others will not stand up very well due to the GP system that stays on for 2 min at startup.

 

ZD-11 are the ones im using, the ones I put in last year are not though could that be the cause of the fouling is the gp itself?

 

That I believe is carbon buildup, and I think it is due to the type of fuel used. Some fuel burns cleaner than others. Just a guess though

 

Well the only plugs that are recommended here are the ZD-11...im sure others will agree with me. I an autolite or some other brand was used then it was probably why they burnt out. If I were you I would probable change all 8 GPs and put in brand new ZD11 and also change the GP relay. With all that good You should be good as new.

 

Thanks for the help, and i'll definitly do that in the next few day. Again thanks for the help!