Thank you for the replies .I installed a blower cam in the 5.9 .I did the adjustment with a multimeter as the shop manual says. .It is a bear to crank now . I need to haul it over 100 miles to get a tune on it but the weather here has been so crappy that I keep tinkering with it .It is an ongoing project that I hope to get going this spring .Thanks again DerTruck and Moparite

 

As an UPDATE to my CEL and Diagnosis thread, the mechanic's original diagnosis about the CEL being related to the evap system was wrong. I went with the codes I was getting using the ignition key check. Not only did I receive a code 21, but also, now a 52 code appeared, both of which relate to the O2 sensors. Had them both replaced and the CEL reset and so far the truck is running good and no misfire. We shall see ...

On the downside - I tried changing the O2 sensors myself, but they were rusted in real bad and pulled my back out trying, so I let the mechanic do it. It cost me $198.00, whereas if I did it myself, the sensors would have only cost a total of about $70.00. So much for having a rusty truck and a bad back, but the job is done.

 

What brand sensors did you install? Hope they weren't bosch...... These trucks don't like 'em.

I used a pipe wrench, and a large hammer to break them loose. Once loose, they came out fairly easy.

 

I checked the part number on the invoice and they were Denso.

 

Excellent.

 

Well, three days ago I had the O2 sensors put in and now the truck just started misfiring or bucking again. The CEL is not on, but when I did the ignition key check for codes, it pulling a 21, 21, and 52 code again, which all relates to the sensors. These are the same codes i had before the O2 sensors were installed.

The mechanic said because it misfires mostly under load, I may need to replace the coil packs (2), which I can do myself, but I don't want to drop another $100 into this unless I have to. Now the questions is, do I go back to the mechanic and have his check for codes on his end, although like I said, the CEL is not coming on as of now, and have him see if he can detect if one or both of the sensors are defective, or just replace the coil packs.

This is frustrating because both my trucks (1995 and 2004) are doing the same thing. On my 2004 I've already replaced the plugs and coil packs and have purchased an O2 sensors to replace the one that was pulling the code, but right now I want to get the 1995 fixed.

Any recommendations on what to do first on the 1995 would be appreciated. That is, go back to the mechanic or install the coil packs. I don't know, maybe he didn't clear it correctly and that is why I am getting the 21, 21, 52 codes now.

 

Coils may be getting weak, I think the problem is going to be in finding replacements......

 

Yeah, I agree, and the mechanic did recommend me replacing the coil packs next. I went the route of the O2 sensors only because it was throwing the 21/52 codes relating to the sensors, which after disconnecting the battery today and reconnecting it for about 20 minutes or so, is still showing the same code. Not sure if that would reset it, just to see if it shows again, but that didn't work.

In any case, I'm looking into replacing the coil packs now and will see what happens and go from there.

 

Try just disconnecting the O2 sensors, and going for a drive clears up the misfires.

52 is running rich... wonder if you have a leaky injector.... What do the plugs look like?

 

I'll give disconnecting the O2 sensors a try and see what happens.

Here's the story with the plugs ... When I went to take a look at them, they were total rust, so I brought my truck to the mechanic to look at and he was only able to get one plug out. He said he tried others with no luck and didn't want to break any of them and left it up to me whether or not to proceed. He said if just one broke, although he has the tools to get it out, he would recommend pulling the heads, as not to do any damage to the engine, should any pieces from the broken plug fall into the block during the removal. I looked into this and that seems to be what could possibly happen.

As far as the plug he did get out, he said it looked good and as long as the others were the same, I wouldn't have any problems at the present time. I know the previous owners didn't use the truck much, so that may be why the plugs rusted up like that.

Here's a thought ... it is possible that a bad cat could also trigger or effect the O2 sensors and if so, be causing the misfire, correct? I ask because I have a bad cat that has been rattling, so the inside is breaking apart. If this may be part of the problem, I may want to take them out and straight pipe it before spending money on the coil packs.