newbie question

[sanddawg2121]

Hello everyone!
I am located here in the USA.
I am not sure just where i am exactly supposed to post my question (s) so i will post here and hope it is correct. If not i am sure i will hear about it.
Anyway, i have a 1988 Isuzu p/u truck 4x4, 5 speed manuel transmission, multi port fuel injection, 2.6 4 cyl gas engine.
Here is my problem.
When i start my engine cold it does not idel very well but does idel ok. My problem comes in when the engine gets hot(operating temp) while driving under acelleration the truck stumbles and falls flat on it's face. It acts like as if i started out in too high of a gear and it starts to buck and jerk, until it cleans itself up and then will take off. It acts like it is not getting enough fuel (starvation). The truck has over 2 hundred thousand miles on it.
Here is some of the things i have done to it.
Replaced the fuel filter $10 each (twice), checked for correct fuel pressure, replaced the timing belt (chain) and seals $1,000 +, cleaned the MAF sensor, replaced the plugs and wires, cap and rotar $45, replaced the coil $53, checked for vacum leaks, (found none), replaced the oil sensor (2 wire) $12, replaced the temp sensor $12 (intake manifold), replaced the intire clutch system $1,002, added some sea foam $8 to the engine oil and gas tank (additive), the EGR vavle seems to be working just fine, I have checked for fault codes and have found none stored in the computer.
I am not sure where to go from here to find the problem.??
I have been on various Isuzu sites here in the states but i am not getting good info. I am at a point i am going to just start replacing everything i can one piece at a time.
I have yet to remove and clean the EGR crossover tube. Still need to replace the Ignition moduel, $170 for that piece.
I sure hope that maybe someone here can help me figure out my problem. This problem is keeping me from driving the truck.
Please help if you can! As i am at a total loss.
I will add some pics once i figure out how to do this and where they go.
This truck does not have the General Motors engine. It is stamped with the Isuzu letters on the top of the engine. And has the I-Tec stamped on the side of the multi port chamber.

[geeves]

3 things to try although you may of done some of them.
1 compression test and post the results
2 timing You should of done this when replaceing the disi cap but its not mentioned so we cant overlook the obvious
3 When all else fails try this It tells a lot about what is going on inside the engine. Warm the engine as normal then accelerate so as to cause the problem. When it occurs turn the engine off imediatly and coast to the side of the road. Beware of the steering lock and chose the place to do this carefully to avoid mishaps. Remove the spark plugs and examine. Haveing a spare set of plugs will help as you can get home before examination but do note which plug comes from which cylinder. There are plenty of pictures on the net of plug cuts done this way with advise

[bozza72]

I had a simalar problem with my old rover, rover charged me a crap loads of money to change the cpu chip, it didnt fix the problem, i did everything i could think of and it turned out to be the disi cap.......might be worth a try, it only happened when the engine was hot and warped plastic disi cap

[sanddawg2121]

Hello everyone
Well i got it fixed now. I just started replacing all sensors and things like that. Just no go. So i finally replaced the in tank fuel pump and guess what it works perfectly! ;D
So i took it on a test trip in the mountains over this weekend. it purred like a kitty.
I posted a link in your other chat forum. General chit chat room i think? Anyway i posted a link so that you can see what happens to the body when you have no lift kits installed or rock sliders.
I think the doors rub now when opening and closing them. Nothing a big hammer wont fix.
Again thank you to you all for your help in trying to help me get this thing running.