The truck is a 1988 4x4, it has a v-6 engine, 33" tires. I have already replaced the cold start sensor. The truck has 128000 miles on it. I bought it used at about 109000 miles. I can take off the radiator cap & look inside the radiator when the truck is running & see the water/antifreeze moving in the radiator, (of course the truck is cold, not hot). Here are the two problems that I have:

The first problem is starting in the morning or when the vehicle sits for about 8-10 hours. It takes several tries to get it started. It whines over, then when it seems like it's going to start, I pump the gas real fast then it starts to run slowly then picks up speed. It seems that when I pump the gas pedal it seems like the operation is backwards. Example: when I push the pedal down it wants to die, when I leave off the pedal it seems to run. Not the other way around like it is suppose to. I do this for about a minute. Then the truck seems fine once I get moving. It idles fine. I can run the truck for a little while (5 to 10 minutes) & stop it, go inside the store & come back out & have no problem starting the truck. It seems to only happen when the truck sits for several hours.

The second problem is that, when I run the truck on the interstate for about 20 miles, running at about 60 to 75mph the temperature gauge reads really hot, but not in the red zone. I get out to check all the hoses, they all are really hot. When I come to a slow down in traffic or I stop in traffic, the truck seems to cool down to regular temperature. Then when I get back up to that speed again the same thing happens again. But here is the weird thing. I can drive the truck around in local traffic (45 to 50'ish mph) all day long & never have a problem with the truck overheating. Any suggestions or questions please let me know. Thanks!!

sounds like it might be a timing problem, or a choke problem for the hard starting...when it gets hot does it ping or run on when you shut it off??

The truck is fuel injected, I don't think that there is a choke on it. I would think that if there was a timing problem that it would be all the time no matter when the truck is started. The truck doesn't have a problem shutting off or have run on after it is shut off. Like I was saying I can go to the store & get out for a couple of minutes, then get back in the truck & it will start up with not problem. It is only hard to start after it sits for the 8 to 10 hour period.

Could check the vacuum line that feed the fuel pressure regulator for fuel after it sets for 8 to 10 hours.

I checked the vacuum lines, they seem to be clear of any fuel. I just put on a new 13lb radiator cap to replace the one that was on there with was a 6lb. At low speeds I still have no problem with overheating, but at a constant 65 mph the temperature needle appears not to go as far up as it used to. It is still above halfway up on the temperature gauge.