This one has been a head scratcher of a problem, and I need more help!

[X-Cutioner]

This is the first time i have posted here, but i have posted this same problem on other sites and still have not gotten a fix.

My dad has an 89 c1500 stock 350tbi with 700r4 trans with only 100K on it

about year ago he started having issues with power loss, I'm talking take off from a light and just nose dives right there. it started off just being occational and finally got to every time. 1 day i finaly got to drive the truck and it did it to me but the power never came back and acted like, and sounded like i was driving a 4 cylinder. i was able to get it back to his house and pulled the filter housing off and found that the right side injector was not firing.
to shorten the story up a bit i pulled the battery and it started working again but would shut off a little later and the guage cluster would act goofy.
so we installed
used pcm
new pcm

after installing both pcm's it would run great for around a week and get screwed up again so we started throwing more parts at it

used distributer
remaned distributer

replaced because the bearings in the stock ones were shot and growling when the engine was running

plug wires
plugs
ignition module
egr valve

the egr had a crack in the bladder and was causing a vacuum leak

after all these things being installed the problem persisted untill it began knocking some time in novermber
i did some more research and told him that it could be the head gasket, but he didn't want to believe it. 3 days later it finally blew

so

new head gaskets
heads machine and rebuilt due to leaky valve guides
im not sure what else was done due to may dads friend doing the job

now with all that being done it still had the problem with power loss

i was with my dad today running wrecker calls and asked him if he wanted me to drive it home becuase the truck sits quite a bit
he told me that it acts up every once in a while but clears up and doesn't have any more issues

i took it home and about 15 miles from his house it started idling really ruff while i was sitting a red light, it changed, i hit the gas, no power for about 20 seconds. after that i heard a pop from the drive line, the tires chirp (limited slip) and it took off without any more problems.
i got it on the interstate and went to merge, hit the gas and no power at all. i looked at the dash, no warning lights

' drove it like that for about 10 miles and couldn't get it above 60


sorry for this long story
but i had to tell it so everyone knew what has been done so far

this time i was really watching the guages and noticed the oil pressure had maxed out and stayed there. i don't know but could the oil pressure sensor be causing these problems

please help because this has been going on for over a year now and is really wearing on us, we both like the truck and don't want to get rid of it

if you all have any ideas just throw them out here
THX

 

[burganyntan98]

did ya ever find out if the injector started firing again? that would be my first thing to mess with clean and or replace. might check if that injector is getting any signal to fire at all. coulda been a hungry mouse that left a wire frayed enough to connect and disconnect w/ vibration...

 

[TruckinAin4Sissies]

Well you said that when you replaced the ECU(s) that it had cleared up for a little while-- then it acts up again.
This leads me to believe it's an electrical issue.

How's your fuel pressure?
Key On Engine Off (KOEO)?
KOE Running?

Let's get this figured out, it took a while-- but you're at the right place!






-Truckin-

 

[Devs93]

Try the batt if there is a weak batt or a dead cell in it it will cause these trucks to flood the plugs run like poo and almost sound cammed I just went through it on my truck changed the alt had no change dropped in a,new,batt and runs like a champ

 

[JAW's]

I was thinking the same thing trucking but your alot smarter than I am when it comes to this stuff.
This one is all yours

 

[X-Cutioner]

sorry left out the part about the injectors, they are firing alright after replacing the pcm's but it was still acting like the injector was shutting down, thats why we started going after ignition components, but tonight when the truck really got bad on me it sound just like an old model T 4 cylinder with the popping and clunking sound. problem is i was unable to get the air filter lid off to check the injectors because it is held on with just a nut and my dad had taken the pliers out of the truck
im going back up tomarrow so hopefully its still acting up and i am able to check them

if i remember correctly he had replaced the battery sometime in the last year but all this crap was happening before it

i don't know what the fuel pressure is due to not having a fuel pressure gauge set

 

[ChrisAU]

Get a rebuild kit and rebuild that throttle body!

 

[X-Cutioner]

another thing i forgot to mention in this tale
the original tb had started to spray really bad and leaking
i had a spare tb from a 94 350 so i took the injector pods off and swapped them out
after that it had no problem from the spray patterns

im getting ready to head up so ill let yo all know what i find out

 

[illinoisboy]

Have you check the fuel pressure like they said? I know our 88 did that for a while then we put in a new fuel pump and it runs fine.

 

[X-Cutioner]

when i got up there this morning the truck was still on my dads rollback. i hopped upon the truck and fired up the 89 pickup, it started but very ruff start and very ruff idle.
i left it running and grabbed a pair of pliers to pull the lid off the filter housing, when i popped the top of the right side injector was not firing
now we are back to the original problem

i guess my dad got fed up with it and took it to a different shop that deals with electrical problems

on our way there i was telling him the things that you all have suggested and he told me that the last shop he had it in, he told them to check the fuel pressure but they kept telling him that the pressure would not cause the issues he was having
he doesn't believe they every tested the pressure

we would do it our self but we don't have a testing guage or the adapter for the tbi so we could hook up the guage

hopefully these guys will test the pressure but dad hasn't talked to them yet to explain exactly what is going on, he is going to call them monday since the shop was closed.