91 4x4 p/u problems... :(

[HPS]

I bought a 91 Isuzu 4x4 p/u from my neighbor, and it is now my (only) daily driver (about 25 miles one way to work). It has an issue leaking water from the pump (help changing it would be AWESOME since I'm not sure how), and the radiator cap is shot (replacing tomorrow). Also has a decent exhaust leak. Those are known issues, but I don't *think* part of the issue at hand...

The problem is that after I have been either driving it for a while (30+ minutes), or stop and go for shorter distances, or just sit still after driving somewhere (bank/fast food/walgreens/ect drive thru), it will die, then when started (which sometimes takes a while), it doesn't like to stay on.
If I am driving when the issue hits, it starts bucking very very hard and trying to die. It will accelerate, but cutting out at the same time. Sometimes if I increase the load, if will even out for 10-12 seconds, ot times it stays the same. Sometimes when it dies & I stop for a minute, it will run fine once started again. Sometimes it will do the same thing when restarted, and sometimes it won't even start, a lot like it's flooded (maybe it is?). This also seems to happen more on hot days, and when the fuel needle is lower (1/4 tank and below), although it doesn't stick to that at all. I has done it on cooler days and on half a tank+. Seems to be *slightly better since I decided to go from 87 octane to 89, but eh. Ignition/spark should be good, which is where my knowledge from modding cars leads me. It also leads me to fuel delivery, which should be good (as far as I know). I checked the air filter and it is spotless. It doesn't burn oil, although when it dies and has to be restarted, sometimes it will give a poof of white smoke, which I'm assuming is burned excess fuel from trying to get it to catch.

I am kinda lost as I need to fix this asap, but I don't have the financial means to troubleshoot by replaceing part after part. It has just over 200k, although WELL maintained. It's a V6 with TBI fuel injection, and 5 speed.

Any help is GREATLY appreciated!

[justin_b31]

fuel delivery is where i'd start.

I had similar symptoms, albeit with a different car, but the symptoms are pretty much the same.

Unless you have all the guages and such to test fuel pressure I'd try this:

Disconnect the fuel line, preferrably near engine before the fuel filter (this will give ya some room to put the end into a container) get a 1 gallon or so container and put the end of the hose in it. try and start the truck. You should get a even and steady stream..think water hose on full blast with no nozzle (maybe more).

Now granted this isn't an exact test, however it should do.

Since this is a gremlin of sorts, best time to do this is when you're experiencing the problems.