I have a 99 SD 250 LB 4x4 CC with 175k on it. It's been a great truck, regular maint of oil, filters, replaced the plugs 3 times, has 315 KO's on it. It's not a daily driver anymore however with gas prices down I have been driving it more than the Highlander lately. Only part I have replaced is the alternator about a month ago. It burns about a qt of oil in 5-6k miles. It's done this pretty much it's whole life. No smoke out of the pipe. I've got 52k on the current set of 315 ko (they could use a replacement)


4-5 years ago I had a problem with it bucking on the freeway. While doing 45-60, in OD, tacking about 1500-1700, going up an overpass it would buck. Take it out of OD and it would smooth out. Hit the overpass at 70(2000 rpm) and it would not buck. This is all with an empty truck. I bought a few coils and switch them out from hole to hole and that never made any difference. Changed boots on all of them. That was with about 120k on it. It all came back to #1 injector plug. I secured that and the problem would go away. It was always an intermitting type of problem. Now recently it's come back in full force. I have changed the plugs, replaced a couple coils, fuel filter(every 10k), replaced vacuum lines, about to replace the injectors, replaced the #1 injector plug, cleaned the TB. The engine runs perfectly smooth in the driveway. Going around all 10 cylinders and pulling the injector wire and then the coil wire all make the engine draw down about the same rpm and cause a miss. No code has ever been thrown with a CEL. I want to keep this old truck but need to get is smoothed out again.


Sorry for the detailed post. Thanks for the help

 

It still sounds like a common misfire.

You need to use a scan tool in Mode $06, PID $53 (or $51) and see which cylinder(s) is causing the problem. Otherwise, you're just chasing your tail since you don't know for certain where the misfire actually is occurring.

 

Is that a dealer tool or a common obd II. I replaced 7 injectors last night(3 DOA from Ebay). It seems to run a little better but I can still get it to miss. It did throw a code with all the bad injectors but I haven't had a change to read it yet. All coils on the right bank are new.

 

It's an "advanced" OBDII scan tool/ The cheap code readers and entry level scan tools won't read "live" data.

I use my Android phone, a $25 BT/OBDII adapter, and a $5 app (Torque Pro).

 

I buddy has one but it is not at work today, it's a decent one. I googled and found this one you hook to a laptop should do what I need. Do you agree. I should have one anyway. $25 pretty cheap.

 

Well my problem is the same as it was last time. injectors no real fix, new coils on one side, replace boots on the other. cleaned the maf. drove around with a obd plugged in. went down the line pulling injector plugs again. with a 10 cyl engine the miss is harder to detect than a v6. it always took a little goose of the throttle to feel the miss. found #3 injector was suspect. a cleaning and a good push and the truck has been funning perfectly smooth for 3 days. such a smooth running engine. I have replaced one plug and it snaps on and stays on. the others are not clicking on anymore. so more money spent than needed, but it's all good for a truck I haven't make a payment on in 10 years!


these are mine....


http://www.ebay.com/itm/380910834915?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT