My 97 has developed a miss, ( thinking just one cylinder ) but could be two.
It seams to start good idles a bit rough but steady, can run at 70 mph on freeway but engine has a steady vibrating shake to it & noticeable loss of power .
The truck has run good for the 3 1/2 years I have owned it. I would just like soome help in trying to trouble shoot and resolve this problem. I am not using the truck now but will need it to tow in the fall.

 

Have you seen a CEL at all? Check the valve cover wiring harness, 2 plugs on each head on the vc gasket. Look at the pins in there and you should pull the valve covers and look at the underside too. You can isolate the problem by unplugging one injector at a time with the valve covers off and start it. It won't make a mess.

 

No CEL that's almost exactly what I was thinking of doing. I've been reading this forum for a few years now, just needed some encouragement to get me started and on the right track. I would have it scanned but don't have easy access to one right now. Fuel filter and oil were changed about 1000 miles ago, running Mobil 1 5-40. Air filter about 2500 miles.

 

How long since you cleaned the FPR Screen . Its a cheap & easy test ..

Does it happen warm & cold engine?

 

I did the Q-tip thing on the screen when I changed the fuel filter, it was surprisingly clean, the fuel filter was very dirty. Does it as soon as it starts warm or cold and very steady at all rpm ranges.

 

Oh ya, I checked for excessive blow by, Didn't seem to bad but hard to keep the oil cap over the fill hole due to all the vibration.

 

How is the fuel mileage ?

 

I haven't really drove it enough to tell since it started missing, but I am pretty sure its going to be bad. If I don't find/solve the problem by the weekend I may drive it 65 miles or so to have a mechanic friend scan it. Before this problem always got about 15 to 16 empty.

 

A Cylinder contribution test may help if it is an injector problem (fuel) , buzz test for the solenoids (electrical)

 

Thanks for all the reply's, I'll get back you all after I check some things out, fuel pressure, oil pressure, valve cover connectors, and then I'll have to remove valve cover and check there. That should keep me busy for a while.

 

Had a problem VERY similar yesterday. Rough idle, rough start, noisywould run, but would lose power. Absolutely terrible fuel, had a lot of grit. Try pulling the fuel filter and draining the fuel out of the filter bowl. See if there is fine sand like grit. I had to replace the fuel filter as it was completely clogged up (only had 2000 lightly used miles on it) and pulled the filter housing and blew out the lines. Let it run for a while, eventually cleaned it all out.

 

Mark, I took the filter out and drained it this morning, still had clean fuel & filter. It was a easy check but not my problem, Thanks.

 

After checking fuel filter I dove to a Diesel shop a few miles from home and had them put it on a scanner, did the contribution test and buzz tests. The ICP failed, and my IDM failed, I think due to the mods. The test reviled a bad under valve cover connection or bad injector in cylinder 2. I'll have a look this evening, when it cools down a little. Hoping for a loose connection

 

OK I have to ask, I am having trouble getting a socket on the last bolt holding the valve cover on, on the drivers side, its the one in the back there is very little clearance and hard to see in there and reach in there!!! Any tips on how to get that last bolt off !! Maybe I'm just to old to be doing this.

 

Well I got the last bolt off the valve cover (end next to firewall). Called the guy that did the scan for me he told me to use a short socket, u-joint, and 12" extension, 1 /2" drive. It worked perfectly.
What to do next: ?
No loose or burnt wires or connectors, and have all AA injectors on that side.
Replace one injector if I can find one, Replace all injectors, if I can afford it.
Don't know for sure but I think these are original injectors with 145000 miles.