Engine/Transmission (1994 - 1998) Missing at 3000 RPM

[Nick2]

Well guys, Im a bit stumped. I was driving last night and went to merge in 4th gear, usually I can run it up to 3200 or so before shifting into 5th. The truck pulled hard all the way up to 2900 rpm where it cut out like it was hitting a rev limiter. My immediate thought was that something was amiss with my 3GSK, so I pushed the clutch in and floored it. The engine zoomed right up to 3400 without hesitation. Ill try to tell you everything I know about the truck. In other words, the problem only happens under load.



-This is my first tank of winter blend

-Truck smokes and has plenty of power before 3000 rpm

-Just noticed my undercarrige is covered in blowby oil, this is recent... could be from me running it to 3K

-My first thought is timing, which hasnt been addressed and may be now presenting itself with the winter blend.



Please tell me what you guys think, thanks



Nick

 

[98rammer]

my first thought is that it sounds like timing, though i don't know about the blow by. it may be possible that your timing is low, but not excessively low. most trucks i've seen/driven you can see white smoke come out of the tailpipe while under no load. putting a load on it seems to help some... especially when the motor warms up, though it'll tend to smoke on the top end (and maybe pop).

 

[Nick2]

It was dark out so I couldnt see the color smoke... but my thought on the blowby is that an excessive amount of unburned fuel got in the crankcase from running it at 3K and no fuel burning... maybe it's a stretch, I dont know.



Thanks for the response, I'll have to check the smoke color..... It does run like a pig when it's cold though- white smoke, popping and whatnot.

 

[98rammer]

white smoke (not just normal cold morning for a minute or two white smoke) and especially popping is definately timing.

 

[Joseph Donnelly]

Also poor burning from cold ambient air, not getting hot enough in the cylinders.

 

[Nick2]

update

I appreciate the replys guys, they sound logical enough.



in the last couple days the weather has decided to further hamper my fun. Im guessing ambient temperatures are 10 or less. The missing is starting earlier in the rev range now. The truck will pull from down low and then fall flat on its face belching white smoke somewhere around 2500 RPM depending on how cold it is outside (apparently). It's awful similar to cold starts where the truck will belch white smoke at anything over 1400RPM for a couple minutes.



Now I know my findings support a timing issue, but is there also a possiblity it could be a fuel filter plugging up???



Has anyone else experienced something like this??? timing or fuel related???



Normally I would jump into it and just change the fuel filter and check the overflow valve. But like I said it's rediculously cold outside... . burrrr!!

 

[98rammer]

sounds like timing, a good performance diesel shop will charge $90-$200 to have timing done.



does it go away or minimize once the motor warms up? does it do it put out a white cloud when you rev it up to the governor in neutral (make sure it's pretty warm), and only put a little white smoke under a load?



a clogged fuel filter would starve the motor for fuel, but shouldn't change timing much (if at all).

 

[MDW]

Check your fuel pressure

 

[Nick2]

just picked up a fuel filter, I talked to josh peters about timing... . probably hold off on that til I cross out the fuel starvation possiblity. Plus I have no idea when the fuel filter was changed last, so it's a good idea anyway I figure. How much time am I looking at for a filter change, it's frigid and snowing out here and of course I have no garage :{ . Trust me, if I had a heated garage I'd be out there doing proper diagnosis... but a filter is cheaper and easier than a 'gauge and filter' if you know what I mean.



So it looks like I move that yellow lever on the canister, remove the bolt in the center of the canister. . then what?? do I have to disconnect both fuel lines?? Does the canister open on a hinge?? pardon my ignorance, but I'd like to have a game plan before I go out there and chatter louder than the engine. Maybe there's a link with pictures??



Thanks for any help guys, the TDR could teach Ray charles to drive

 

[98rammer]

yes, pull the lever to drain the fuel, and unscrew the nut. the canister will pull down. pull the old filter out, and put the new one in with the new gaskets (lube them up with some clean fuel). you may have limited access, as it's nearly impossible to pull my cansiter up and out. if you can drop the canister and pull it from beneath the truck (or even from above), then don't forget to disconnect the WIF (water in fuel) harness from the canister. i simply pull the filter out from the top and put the new one in. then put the canister back in, prime the system until you hear fuel coming out the overflow valve, and start it.

 

[Nick2]

sounds easy enough, thanks again!!!

 

[Nick2]

solved

turns out it was the fuel filter. thank to eveyone for the ideas and suggestions. The filter was black, kind of a pain to get to - especially in zero degree weather with the friggin snow in my face. Enough whining though, it's done and I got my fuel filter badge. The overflow crack is a life saver, I forgot about it at first and just prime til my fingers went numb... after cracking the overflow bolt and priming it fired right up.



Still want to set timing, but now Im not in such a hurry. Maybe Ill save up for some 370s first. . :-laf



hey they're on sale!



take it easy, Nick