Care to throw a guess at this problem?
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Tuned
Joined: Feb 2005
Posts: 380
Likes: 1
From: ohio
Care to throw a guess at this problem?
I built up a 97 SD (450) over the winter, some of you have seen the pics I posted. It was fleet truck and seems to have been given reasonable maintainance but I have no history. Has 145K miles. Problem is a cylinder that comes and goes and has my mechanic, who is reasonably good with PS diesels, baffeled. Tests he has run are cylinder contributuion and several other tests his scanner runs with engine running. A "buzz"? test and a compression test. He has had the harness apart and visualy checked them along with Ohming them. All tests come back OK and compression is right on the money. Now on to the miss. Truck starts instantly in any weather and runs imeddiately on all 8 with no smoke. I always let it run for a couple minutes when started cold and it runs great and has super power until warmed up. Once warm you can be driving down the road and everything is great until you stop for a light, When leaving the light it will completely drop a cylinder if you quickly lay into the thottle. Same thing will happen if you coast down a long grade when you get back into the throttle. If you ease into the throttle it wil miss a couple times and come out of it, if you lay into it it will miss until you let off and ease back into it again. This is a dead miss and on one cylinder. Sometimes when it comes back there is a pop out of the exhaust. (straight pipe right behind the cab) When it is running on all 8 it has terrific power, it isnt even half bad on 7, LOL. The mech thinks the injector plungers?? are worn one of them worse than others.and warm oil is too thin to pop them off but he is a leary of asking me to spend the bucks for 8 injectors to find out. Is there any way to monitor the thing going down the road since it wont miss in the shop with his gizmo hooked up? Does his reasoning about the injectors sound reasonable. Thanks in advance.
Postmaster
Joined: Jun 2007
Posts: 2,795
Likes: 1
From: Rogue River, OR
One tester is the autoenginuity that will hook up to a laptop and you can do many diagnostic tricks while driving. The bad news is the unit costs $400.00
But....That is a lot cheaper than just replacing all of the Injectors. I would check around town and see if you cant find someone with a unit that is portable to be with you so that you can create the problem.
Rog
But....That is a lot cheaper than just replacing all of the Injectors. I would check around town and see if you cant find someone with a unit that is portable to be with you so that you can create the problem.
Rog
Hotshot
Joined: Aug 2006
Posts: 10,764
Likes: 39
I built up a 97 SD (450) over the winter, some of you have seen the pics I posted. It was fleet truck and seems to have been given reasonable maintainance but I have no history. Has 145K miles. Problem is a cylinder that comes and goes and has my mechanic, who is reasonably good with PS diesels, baffeled. Tests he has run are cylinder contributuion and several other tests his scanner runs with engine running. A "buzz"? test and a compression test. He has had the harness apart and visualy checked them along with Ohming them. All tests come back OK and compression is right on the money. Now on to the miss. Truck starts instantly in any weather and runs imeddiately on all 8 with no smoke. I always let it run for a couple minutes when started cold and it runs great and has super power until warmed up. Once warm you can be driving down the road and everything is great until you stop for a light, When leaving the light it will completely drop a cylinder if you quickly lay into the thottle. Same thing will happen if you coast down a long grade when you get back into the throttle. If you ease into the throttle it wil miss a couple times and come out of it, if you lay into it it will miss until you let off and ease back into it again. This is a dead miss and on one cylinder. Sometimes when it comes back there is a pop out of the exhaust. (straight pipe right behind the cab) When it is running on all 8 it has terrific power, it isnt even half bad on 7, LOL. The mech thinks the injector plungers?? are worn one of them worse than others.and warm oil is too thin to pop them off but he is a leary of asking me to spend the bucks for 8 injectors to find out. Is there any way to monitor the thing going down the road since it wont miss in the shop with his gizmo hooked up? Does his reasoning about the injectors sound reasonable. Thanks in advance.
Injector poppets ?....
