No. It is like the ECT. Nothing has shown up to point it out as a problem. I had some fast idle issues a few times, but I fixed some vacuum leaks and have not had idle issues since. I'll add that to my list of things to look into.

On the injectors do you have any concerns with used vs new vs rebuilt?

 

Generally speaking, I think new are a waste of money if you can find them rebuilt, and I avoid used ones. However, I have heard good things about the people selling the used ones I linked to, and would go with them first, especially considering the price.

Do you have a DMM with a bargraph?

 

The TPS my not throw any codes when it goes bad. Had them go out on the Cougar and the 150 and didnt get a CEL either time. The ECT is cheap, I had some issues running too rich and I pulled mine to take a look at it and the end was coated in crap, used some emery cloth to clean it and the truck ran better (just havent had time to pick up a new one yet)

As far as the injectors it is definately recommended to replace them as a set, even if you can isolate a leaky one the others probably have some junk buildup in them and will not flow at the same rate as the new one.

 

Took the truck for a test run with my trailer(empty) today and I did not hear any knocking. On the best grade for me to pull, it came a big thunderstorm. I couldn't hear anything. I noticed quickly on the hwy that the truck acted differently. On another hill(rain stopped) it accelerated smoothly and I tried to make it knock and could not. It ran the best I've known it to.

I did 4 things to it and am not sure which did it.

1. Seafoam in the intake and tank.
2. Changed misshaped dist. cap and rerouted tangled plug wires.
3. Changed the fuel pressure regulator.
4. Cleaned the plugs(weren't really dirty but I had them out to check)

I am leaning toward the cap first and the seafoam second.

I plan to tow a load in a few days and will be able to see if it is really better. I ordered the injectors today and hope to use them next week. That should really help it.

I picked up the ECT but have not installed it yet. I plan to keep it with me and put it in if the truck acts up again.

 

Good deal. I suspect that all 4 things played a part, but don't discount the importance of keeping the plug wires neat and separated. There is a lot of voltage going through those wires, and it is very easy for the signal to jump from one wire to another, especially when the wires are bunched together. If I had to bet on which of your four accomplishments had the greatest affect on your pinging issue, I'd say the wires first, followed closely by the seafoam.

 

Yesterday I cleaned the upper intake and TB and changed the injectors. I am still losing pressure, but it seems to hold a little better. I think it starts quicker and holds pressure a little longer on prime. The running pressure is the same 32lbs. The injectors seem to do well and I will be towing in the next couple of days to really give it a test run. I also changed the temp sensor while I was into it. it sounds like the fuel pump is an issue. In some ways I believe the injectors and pump were both leaking. I hope to pull the bed to clean and paint my frame and will do the pump then.

I am going to run codes today and check everything out again.
Thanks for the help.

 

Ignore my previous post. My truck still runs like crap and apparently I've got no business giving advice! If I ever figure it out, I'll post the solution. -Al

 

Thanks for the response, but hang in there. I take note of the responses I get, but do my own troubleshooting. I appreciate any insight that I get, but make my own choices based on what information I receive.

By the way, have you done anything with your computer? I wouldn't recommend changing it for no reason, but I understand that they rarely tell on themselves. When I first took my truck to the dealer, the tech suggested that it might be the problem. Instead, I have found multiple problems, most of which have been simple.

 

I took my truck for a haul today, 1.5 hours with about 3500-4000 in tow. I had no knocks or pings. The truck topped the worst hill at about 45-50 and ran strong. On level ground it held 60-65 with no effort and would have kept going. It did heat up a little on grades. By the top of the worst inclines, the gauge was at or near the L in NORMAL. However, it cooled down. I am wondering if my water pump may be getting weak. I hear some squealing coming from the front of the engine.

The motor still seems to have a light flutter at idle. I may need to go ahead and change the wires and coil. It runs strong and smooth otherwise.
Thanks for all the help.

I am debating on selling this truck, while it is running good and getting a newer model that doesn't need as much work, especially body. These older trucks seem to be a lot easier and cheaper to work on, but mine has kept me busy.