How do I splain????

[Chris]

94 dakota 3.9L
I have done a lot of work on this truck the year I have had it. It needs a rebuilt tranny but was otherwise doing well. Since I took it in and asked them to “see if the engine is running right” it seems off and the pulley wheels have started to whine a bit. Its never done that before.[EDIT The point of that diagnosis was to make sure what seemed like tranny problems was not an engine problem. They said the motor (on the sheet the mechanic suggested a misfire with ? next to it)was fine and diagnosed the tranny as slipping needing rebuild. I did not give any indications of problems so I didn’t create a problem by what turns out was incorrect use of descriptive terms. For instance what I called jumping was what they and the tranny guy I went to called slipping.]
I checked the wires and found the coil wire was not fully on and lubed the pulleys and things were ok. Then the other day I started retaping and taping over the frayed old friction tape on the wiring harness in the passenger side of the motor compartment near the firewall. After I did the the motor seemed to respond better to my peddle input but an old problem has come back. The valves are ticking a lot when its under strain on a hill or if I try to accelerate fast. ????? [EDIT It’s losing power like it did before I did the Hughes Engine Intake Plenum Kit and Timing chain/Tensioner. I went back over the intake bolts and a couple of them seemed loose on the middle passenger side.]
I’m on page 7 or Solving Performance Issues and not much help yet. I will try a power balance in a bit. I wonder if the guys who were checking on it may have turned the Distributor and threw the cam off?

Topic

[Chris]

I did the power balance test by pulling the plug wires at the plug and it went as shown in the video. So no cylinder problem from that pov.

I’m tending back to my idea that the PCM may be screwy which you guys lead me away from and helped diagnose the tranny. I will be getting iot rebuilt as soon as I get my other truck running which is on schedule to be done by next Friday if deliveries come and UPS hasn’t broken the head.

[Chris]

I decided to pull the harness connector to the PCM and sand actually fell out of it when it lay over away from the PCM. I wiped it down sprayed it and the PCM with WD and put it back in. I drove it for a while and there is a marked improvement including in transmission performance. It went up to 4Krpms getting on the highway just as it should no struggle and basically drove like a everyday driver little truck. When I got off the hwy it did have the slip from a start that it gets when the tranny is hot.

I’m debating if I should install the new TV cable & return spring I got to see if that slip goes away since a bad TV cable adjustment can cause this.

[Bill]

I’m a little confused with your help request but I will say that it’s not the valves that are noisy but spark knock (pinging) likely from over advanced ignition timing If your timing is adjustable (throttle body injection) I suggest you set it with a timing light with the coolant sensor disconnected.

[Chris]

Sorry its so confused.
Thank You but the pCM sets the timing on this and when I did the intake plenum and timing chain a few months ago the distributor was lined up perfectly with the mark it is supposed to be lined up on when you look down on it.
Before I redid the friction tape the issues had been pretty much diagnosed and were waiting for me to get it into the shop. After I put on the tape something new happened in that it changed how it ran both for the better and worse.
Since I disconnected the harness and cleaned. WD’d the connections it has stopping having spark knock and almost acted as it should. There was some lack of power or less power than I feel should be there and the slipping tranny when its hot.
I had started thinking the PCM might be what is causing the tranny to act funny and in my obtuse way was asking if that sounds right. This is embarrassing SORRY too much interweb posting I forgot to run it through my editor. 😐

[Lorrin Barth]

You may of had some bad gas. Anyway, pay attention to the octane ratings on the pumps. I was just out in Wyoming where they had 87 and 87 at the pumps. What’s that for except maybe lawnmowers?

[Author]

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