rusted

My issue has really gotten the best of me. I replaced the rear gas tank, installed 2 new fuel pumps and filter because the rear had pin holes in it. I done this because I was getting a crank / no start issue that was intermittent and I replaced the ignition coil and it didn't fix the issue. Well that wasn't the problem. I then replaced the ICM just because From reading this site I found the "pip sensor" sounded like it was the issue so I replace with a new distributor and set the timing to 10 degrees BTDC and put the spout in and it ran fine, or so I thought. I went to drive it a few days later (7 miles) just to test it out and it was good so I came home to grab some things to go to town. I got a mile down the road and under load the valves were rattling and it started bucking so came back home and parked it. Seems like it runs fine until it gets to normal running temperature then it bucks and valves rattle under load. Today I took it to the shop and they hooked it up to the comp and it wasn't throwing any codes. Vacuum is good, has good pressure at the rail and the EGR is fine. Mechanic said it was the ICM and that I might have gotten a faulty one because with the spout out it runs fine. I drove home with it out and indeed it runs fine. I returned the ICM and got another new one and the problem's still there. He said if the ICM wasnt the issue (which he was sure it was) that my cat may be the problem.

Before the start / no crank issue I never had this issue. Any thoughts or advise?

memoniz

Look up threads about the TPS (throttle position sensor), see if those threads sound familiar. I never had the problem but a friend of mine did. It would idle fine but when he took it out for a drive it bucked, sputtered, and stalled out at times. He switched the TPS and it's running fine (or at least that was what I was told when I last talked to him).

rusted

I put the old ignition coil back in to see if it made any difference out of curiosity, but it didn't.

KOEO Codes I got by jumping is as follows:

1
21
23
32

Mechanic said there were no codes.. Idk

sdmartin65

Temp sensor or cats, if cats are that bad though wouldn't be much exhaust flow. Temp sensor going out can cause strange problems, common to start reading lower than actual engine temp.

rusted

Well I get decent exhaust flow from the exhaust and the temp gauge is where it's always been when running. Just a little under half on the gauge. Sorry I don't have the numerical values for the temp. I'm going to take it to Advance tomorrow just to double check my code findings to make sure I haven't misread them.

sdmartin65

The ECT sensor is separate from the gauge, about $15. There's a way to test, easier to buy a new one cause have to remove to test. What usually happens is engine temp is at operating, say 200. The ECT reads it as 150. You see what kind of problems that causes.

Codes are 3 digit. It can throw a ECT code but has to very bad to do it. Normally it will just start reading lower. To throw a code it has to read as above 256 or below 0 after having run for awhile.

rusted

Well I took it to my cousins shop today and he hooked up his reader and it showed only (33) EGR valve opening not detected. He done a vacuum test and said it's working. He's leaning towards the cat being bad because the exhaust at the tailpipe is scalding hot. I also watched my temp gauge on the way there and it is fluctuating a little so I'm going to pick up a coolant temp sensor as well..

rusted

Still baffled. I wonder if the new dizzy is defective? Before the start / no start my truck never had spark knock or the bucking. When it was acting up not starting it would crank one day and not the other and I would drive and it was fine. I did reset the computer do you think I should keep driving it and maybe the computer will level things out?