I have noticed that my engine is getting a little harder to start than it used to, normally soon as the glow light went out the engine would make about a half revolution and it would start , now I have to turn the glow plug light on twice for the same result. I have a new battery and have checked all glow plugs what bothers me is it will do this even though the ambient temp. is 100. Does anybody know what might be the problem? Thanks

Your GP relay works on info from the front temp sensor under the GP on the injector side of the engine. This sensor could be reading wrong or the relay isn't working right. You mught first check tyhe GP to see if they are all working right if you haven't already.

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1977 300D Lost coolant while someone else was driving
1983 300D Can't run without oil
1985 300SD (gone but not forgotten)
1990 300TE 4matic Sold
1991 Yamaha Venture
1975 Kawsaki 250 triple
1974 Honda 200CL
1951 8N Ford
2008 Wildfire 650C

also a description of how it is acting will help. also year and model.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

84 300 turbo , I have checked the glow plugs and they are all working, the glow light stays on for about 3 seconds its was about a 95 degree day, if I just wait for the the first light to go out it makes maybe one revolution before it starts if I turn the glow plugs on twice it pops right off about a quarter revolution once it starts in either situation it idles fine. It used to always start with a quarter revolution turning the glow plugs on just once. The car has a brand new battery. I was only able to do a resistance check not a current check on the glow plugs.

Everyone needs to put their year, make and modle in their signature file so we don't have to guess......saves forgetting to detail it on every post you make if you own only one.

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Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

It looks like his year and model were in the subject line in the initial post after all. I think it would be appropriate if people would start reading the subject line before they start accusing others of not posting their year and model. I've seen it happen many times. That's just as big of a problem as those that do not post their year and model.

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'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)

Still a good idea to do the sig file thing....its usually the newer members who haven't done it.

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

The model and year was in the first line of his post - I also thought he had a pretty good description of the problem in his first post. Maybe people need to read the description of the problem a little more carefully before asking for additional information.....

My 1991 300d 2.5 turbo does the same thing - it starts faster at 32F than it does at 90F. What appears to be happening is that the glow plug relay timer only sends power to the glow plugs for a second or two at really high ambient temps. If you manually applied plower to the plugs for 5-6 seconds you would find that it would start instantly - just as it does when the timer energizes the plugs at 32F.

Thanks for the information, I thought I had given enough information on the orginal post.