hello alll this will be my firsy post. Ineed a little help with my isx. At idle she runs really ruff,when running down the road she runs fine and pulls well. the truck is a 2000 pete with a non egr isx. last may i had the head replaced and injector #4, in the shop before I drove off I noticed that she had a miss if you will the so called mecanics said their work had nothing to do with the problem but would be happy to diagnos ($$$$) i was out of time and money. after a while I took it to the local cummins . The 1st time in they spent 3 hours washing the motor and pulling the cover off, the second time in about a month later the lead mecanic told me that I could run it that way or they would be happy to diagnos ($$$$$) with no idea how long it would take to figure the problem. since the Ive replaced cam and crank sensors, ambient air, injector # 3 and 4 and several others including the lift pump. she will idle and run better with the new elec pump off, also replaced the pressure regulator under the fuel selenoid and she idled worse so I put the old one back in. the only code she posts is a cylinder inbalance. As you can see I could use a little help, any insight would really be helpful. thanx

 

I believe I would find another shop to take a look at it. If a shop wants to do a diagnostics run, but can't tell you how long it would take to find a problem, tell them they have already given you that.

 

thx for the response. the head was done by a kw dealer because of convience and the service manager before he became the service manager had worked on my equipment for the last 14 or so years. the second and third time was by cummins, they saidf run it till something shows itself. Just hard for me to believe that Im not doing damage to other places (cams, crank)

 

I know a guy who had a Cummins and had an intermittent miss. He replaced the ecm and other parts but could not solve the problem. It never seemed to have the problem when they checked it. Ultimately, it was an injector. The guy's son had always suspected it but could never catch it when it was having a problem. He put a spare injector in the truck and happened to be driving it one day when it started. This time he found which injector had the problem and fixed it on the side of the road. Problem solved.

 

thanks for the reply, Ive kinda thought that be the problem, the problem with carrying an extra injector is that in my part of the country is that cummins wants $500 each and a $480 core.

 

after replacing 2 injectors at about 8 months apart & a lot of downtime. I wished i had done all 6 at the same time & been done with it.

 

some injectors go out where you can make it 300- 400 miles. some go out where you wont make it 50 miles. i had both happen to me. kept an eye on oil & oil press. where will you be when it goes & if it goes bad quick? paying for a tow from the side of the road to whoevers shop.. your at their mercy.. get em all done with the overhead & have new ecm harness checked & replaced if needed.

 

Good advice. What I was thinking was that after oem in jan 09 (so Ive been told) injectors can be purchased at a fraction, If and when this happens I will purchase all 6 and put them all in myself. Fortunately I can do this especially since on my isx they are mechanical.