1996 Nissan Pickup 4x4 hesitation issue

[Gearly]

I recently purchased a 1996 nissan pickup xe 4x4 5 speed 2.4 with 147k miles on it. Ran great for the first 200 miles after purchase. Now I have noticed a hesitation when the truck gets warmed up. When I first start the truck, she runs like a top. As soon as I reach temperature, I notice that when I let off the gas, it jerks when slowing down. It doesn't matter what gear I am in, the same thing happens. I have also noticed some white smoke from time to time once the truck gets warm. I am not too familiar with the carb setup in these trucks and am by no means a master mechanic. The truck is not overheating, nor does it have any issues at all before it reaches operating temp. I also noticed that when I pulled a trailer the other day with it, it began to bogg down and was very hard to get up to speed. These may be separate issues but any help on where to get started would be greatly appreciated.

[Desert Rat]

almost sounds like it's overheating. White smoke is often a sign of water in the oil, i.e. blown head gasket.

Check the oil and look for beads of water on the dipstick. Also, pull the plugs and see if they're fouled. Plugs should be a light brown in color. If they're black or wet, that indicates problems.

[Gearly]

Pulled the plugs and they are fine. No water in the oil or antifreeze in the oil. I thought head gaskets too but it does not have any white smoke at startup and only after it runs for long time does it smoke "some times". It smokes rarely and I just can't wrap my head around it. It runs great until it reaches operating temp then hesitates and jerks when letting off gas pedal. I did notice the radiator cap probably needs replacing and when I took off the oil cap while truck was running, it does have a lot of compression blowing out of oil cap. It is like a blow drier on medium speed blowing out of the oil cap. Don't know if that is norMal with these engines

[whomadewho]

When pulling a trailer sometimes a person underestimates the load weight x empty trailer weight. The 2.4 isn't by far the most powerful or fastest. Given the radiator size and the fluid capacity I would be mindful pulling a trailer. It's common to have oil come out of the filler cap when the engine is running. Smoke coming out wouldn't be something you want to see. I have been dealing with the jerking motion on my 1997 for a couple of years. I don't claim to have the answer and I haven't taken the time to resolve the issue. The jerking issue occurs several times a year. I've been using a temporary solution to get me by. I have been using a foam throttle plate cleaner. I remove the air cleaner and with the engine running spray the throttle plate slowly for a half a minute,then spray a heavy amount until the engine stalls. Let the truck sit for awhile before starting (might start hard). Take the truck for a ride, sometimes it works the first time. In the past it has taken several attempts but eventually it has worked.

[whomadewho]

I suspect it's a throttle position sensor just haven't taken the time to check it out. You might want to spray the sensor.

[whomadewho]

Couple of other things to check - engine temperature sensor - vacuum hose leaks around the EGR valve and the EGR control solenoid valve. (Located R. side passenger side above the oil filter or below the battery, toward the block. Make sure the vacuum line that goes from the EGR control solenoid vale to the bottom of the air cleaner is still connected. A lot of times when the air filter is removed it gets forgotten during installation.

[whomadewho]

Another thing to look for would be a leaking intake manifold gasket. Take carb cleaner and spray between the intake and head especially between number one & 2 fuel injectors ( when engine reaches operating temp)

[Gearly]

It was a head gasket. Pulled the head this week and it is getting a valve job then I'll put it all back together when I get a chance