Starts runs like sheet then dies

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
After installing my built engine the truck would run fine untill it started warming up. its like some one flicks a switch on and off. and no codes. The eng seems to shut off and back on. Its violent. The longer it runs the more it does it. I did the larger oil pump upgrade front cover and piston squirtters. It used the same electronics as engine removed. I thought it might be the crnk sensor distance from reluctor. I pulle out the sensor today and stupidly guessed at it. looked like about 1/8 inch . so i took about 1/16th off put her in. now it starts runs like shit for a bout 20 seconds and dies. lol whats a proper spacing? pulled sensor back out and it did not hit (no marks) What say you?
 

2004LB7

Well-known member
Dec 15, 2010
3,456
244
63
Norcal
I don't think it would start with bad or no read cam or crank sensor so I doubt it is that. I would almost guess it is tuning related if it seemed to start fine then have trouble once warm. But it may be something else like a fuel leak that gets worse when the fuel is hot and thin. May need to do some logging to see what is happening. Very hard to do anything on the other side of a computer without more information
 

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
I don't think it would start with bad or no read cam or crank sensor so I doubt it is that. I would almost guess it is tuning related if it seemed to start fine then have trouble once warm. But it may be something else like a fuel leak that gets worse when the fuel is hot and thin. May need to do some logging to see what is happening. Very hard to do anything on the other side of a computer without more information
Thnks for the response. Its NOT tuning. does the same shit with a stuck file in it and 7 revisions from broviak for other issues not related. it holds rail pressure so we can forget that. As I stated It did the on off thing and I thought maybee the sensor was to far from the reluctor with the new timing cover so I shaved a bit from the spacer between sensor and cover. now it stars runs like sheet then dies. PLEASE some one just give me the air gap setting and we will start there.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,205
155
63
Texas!!!
I looked in ProDemand but couldn't find a spec for the CKP sensor spacing. Why do you suspect it isn't correct?
 

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
Hehe. in my first post i sad that I changed the front cover and did a bunch of mods to the oiling system. Then I stated that I physically shaved some metal off the sensor spacer because it was about 1/8 inch away. You wont find shit in pro demnad because it sucks. so does alldatapro. I have all those systems =)
 

2004LB7

Well-known member
Dec 15, 2010
3,456
244
63
Norcal
Google search says 0.02 to 0.05 or about 1 mm (about the thickness of a credit card) seems normal
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,205
155
63
Texas!!!
Hehe. in my first post i sad that I changed the front cover and did a bunch of mods to the oiling system. Then I stated that I physically shaved some metal off the sensor spacer because it was about 1/8 inch away. You wont find shit in pro demnad because it sucks. so does alldatapro. I have all those systems =)
I measured an LMM I have sitting in the floor, and it shows to have about .03" gap.
 
Last edited:

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,205
155
63
Texas!!!
Wow, that's tight
Yeah, thats because that was a typo with one too many zeros. It was .03" clearance. I'm going to edit the original post so someone doesn't see it and get the wrong info if they don't keep reading.
 

2004LB7

Well-known member
Dec 15, 2010
3,456
244
63
Norcal
Yeah, thats because that was a typo with one too many zeros. It was .03" clearance. I'm going to edit the original post so someone doesn't see it and get the wrong info if they don't keep reading.
Ok, that makes more sense
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,205
155
63
Texas!!!
Ok, that makes more sense
What's funny is I looked at your post before I made mine and said to myself, "he was pretty close on his range since I'm right there in between his numbers." Then I went and typed it wrong.
 

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
thanks for getting a measurement for me fellers. I changed out the timing plate Id call it. With one from a n LB7 I have around. now lol it wont start but tries twice then just cranke. I hate the modis. P0336 no 01 02 03 ect. Look at the freeze frame and it says sht to gnd. Now ill chase that and make sure I have the air gap right.
 

gmduramax

Shits broke
Jun 12, 2008
3,762
47
48
Nor cal
Check the ground at the end of the crank and cam sensor harness. Had the wire break inside the insulation and gave me hell.
 

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
thanks for getting a measurement for me fellers. I changed out the timing plate Id call it. With one from a n LB7 I have around. now lol it wont start but tries twice then just cranke. I hate the modis. P0336 no 01 02 03 ect. Look at the freeze frame and it says sht to gnd. Now ill chase that and make sure I have the air gap right.
Im hopin. this problem because of my lack of time to work on it has kept it down for about 2 years now
 

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
Stupid problem. I bought it from a used car lot knowing it needed help. He did not know it was deleted and plugged in one of the egrs. Unplugged it engine runs great. Now off to build a trans for it
 

fl0w3n

Member
Jan 8, 2015
508
24
18
Wait so the problem the whole time was an egr? I’m not following your last few posts
 

Madspeed

Fat Bastard
Mar 22, 2007
279
3
18
Elk Ridge Utah
Shit umm lol to manyproblems. This egr issue was my new 2013 2500. Scratch that shit. I work so fokking much I dont know what friggin day it is.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)