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I recently acquired a 90 f250 4x4 auto for real cheap(free). However, the previous owner ran it hot and now it runs rough, like a dead miss on one of the cylinders. What could be the possible causes for the miss? He also said it started smoking since it ran hot. Im gonna check the plugs tomorrow. Hopefully that is the prob, but can a plug get burnt/cooked? Some one suggested a burnt injector, but is that common/possible?
I just got it fired up today as it came with no batteries. I picked up some used ones just to get it cranking. Also, the batteries are 675 cca and will that cause me probs in the winter?
It fired right up and idles fine, but when you hit the gas, it misses terribly. but I didnt notice any smoke.
Any input would be great.
Dead miss could be many things, burnt valve, IP advance piston problem, worn rocker or bent pushrod.............
If you start the engine..... then crack the injector lines one at a time 1/2 turn+ so the injector falls of line/stumbles. If any cylinder has no or vlittle effect on the engine running then that would be the one to check.
Indeed, it could be many things. However, I want to know what would the be most likely problem that is related to the engine running hot. I am certain that its current condition is a direct result of the PO running the engine hot. I know that is common for gasoline engines to blow a head gasket, but how common is it for a diesel engine?
Since the diesel runs twice the compression of a gasoline engine it is possible.
Depending on how cold the winter temps are in your area will determine how big the batteries need to be.
I start many mornings at or below zero.
I run 950 CCA batteries.
ok, do you have to pry the plugs out of the head? I unscrewed them but I could not get them out. Im pretty sure I got them backed out all the way out but they will not come out. I didnt try pliers or anything but do you need to? I went to fill the rad, but the lower hose needs to be replaced. Also the brake line is busted, so I will be busy for a while trying to fix those probs. The winters around here get cold but not at or below 0 degrees F.
The miss problem could also be one or more injectors with a stuck plunger in it. I had this problem with my 94 F250 IDI until recently. I pulled the injectors, removed the tips and lapped them. Engine runs much better now.
If you are trying to remove the glow plugs but they won't come out, the PO evidently used cheap plugs and the tips have swollen. Sometimes you can loosen them as far as they will go and start spraying some good penetrating oil around them. Then work them back and forth with some vise-grips while pulling. If you have the misfortune of breaking one off in the head, it's time to pull the head. Always use only glow plugs that are stamped with the letters BERU on them.
Last edited by mechmagcn; Sep 23, 2007 at 05:19 PM.
ok, thanks for the heads up on the plugs. I think I will try again when its a little colder out. If/when I pull the plugs, they should be replaced, right? What brands are recommended, Bosch, Motorcraft, Autolite?
How do you lap the injectors? Oh, another thing...I noticed there was an extra fuel line in the cab, its brand new, from ford. Upon inspection, the line on the truck seems to be damp/wet where it connects to the IP. I would assume that it is leaking and may be the source of the miss. But is that likely? It seems damp, but not squirting out at a large rate.
Any leakage could cause a slight miss, the more fuel leakage, the more miss. If it is not sqirting fuel, that is not likely your miss. Lapping the injector plungers isn't a job for the novice, I have experience in working on injectors and pumps. Also, the injectors should be tested and the pressure set after doing this.
ah-ha, yes im a novice to diesels, as you may already know. So, I guess I should tackle the plugs first. after I change the hose and brakeline. Thanks.
First I would read Ziggster's web page re removing the GPs.......
http://www.members.shaw.ca/k2pilot/ there is a right and wrong way..... the cylinder your working on must be at TDC.... so read up on the timing info to.
that was very infromative. I would assume that having the cylinder tdc would create pressure in the cylinder, which may aid in pushing out the plug. Right? it would be easier than hooking up compressed air or the plier/wiggle method. Thanks, I have printed this out and will have it handy when I do the plugs. I also noticed that he only recommends motorcraft (hence the BERU) and strongly dislikes autolites. I may have to go with the bosch as they are more easily available.
You do know that the glow plugs have nothing to do with the engine missing, right, since the glow plugs warm the engine prior to firing, and do absolutely nothing while the engine is running, right?
oh yea.....ok, with that being said, I wont mess with the plugs as it starts fine. I knew that at one time however Ive never really messed with diesels before and most knowledge ive learned was lost. Ive havent worked in a parts store for over 2 yrs and my current job is nothing related to the automotive industry. well alrighty then. back to the drawing board. I was hoping for a simple solution.