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I am very new and i need some advice please

Melvin Colbert

New Member
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Location
Ga
I have a 6.6ford diesel the brizilian one. It is misfiring on the number1 cylinder. New injector has been installed and a compression test. 1992 model f 700 . 171000 miles. Fuel is reaching all injectors.
 
I can’t remember the brazilian one- it’s differences.
What injection pump and injectors are used? Full mechanical, mechanical pump and oil assited injectors, common rail, etc.

Assuming compression test without posting results means all cylinders within spec?

Any smoke because of the miss? If so what color and smell?
 
Bosch mechanical pump. Injector has a line that screw on top of injectors that distribute fuel. Just sit an idle no smoking. Just a little skip or miss. Try to drive it is very sluggish till it gets going ,if I hit a hill it is like I turned the engine off.
 
Sorry, I was thinking of a different design that I knew of a wacky issue on. No help to this one specifically.
You have the inline 6 with inline injection pump, right?

When diagnosing a bad injector, I always swap it with another cylinder that is operating good. Say #1 has the missfire. Swap #1 injector with #2 injector - if the problem is now in #2 and it fixed #1, you know it is the injector.

If you have not done this, try it. New injectors come messed up sometimes. Also if the problem stays in that cylinder, you know it is the cylinder not the injector.

So your compression test was good, and matched the other cylinders, did you do a leak down test at same Time?

Are your valves adjustable? Consider something in the valve train not opening a valve all the way.

Have you done the thermal gun test comparing cylinders to see the weak cylinder and if so what were the temps?

If you have engine I think you do (Brazilian thing has me scratching my head) Inline pumps differ from a rotorary design in that the pump itself can wear out one cylinder at a a different rate. The good thing is they are individually adjustable- the bad part is it HAS to be done on a test machine. Just a wiggle or tightening down the lock can move the volume a descent amount. Pricey for a rebuild or even just bench adjustment, but if the guy is good it will make it feel like a whole new engine. Obviously exhaust options before getting to that step.
 
You could undo the fuel lines from the injectors, secure each one into it’s own bottle.
Then crank the engine 30 seconds, wait 30 for starter to cool, do this 3 times. Let starteter cool 30 MINUTES after 3rd time. Repeat it 3 times, so it will be almost a 2 hour process. Reattatch the lines, and bleed
The injectors to start it,

Compare volume of fuel of the “bad” cylinder to the other 5 and see if the pump is not supplying same quantity. You need to be very accurate in your measurements there will not be much. 10% less fuel in 1 cylinder accounts for a lot.
 
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