Hey all.
Figured what the hell try a forum see ifI can get an answer here. Seems no matter who I ask or what I replace I can't get my truck to run right.

I have a Chevy 1990 5.7 4x4 reg cab. Its got some issues but Im lost.
Everything hooked up the way it is supposed to, Cold or Normal Operating temperature the truck idles up and down up and down for like ever. I unpleg the wires to the Map sensor and it stops. First think I think is facumn problems. Well replaced all my hoses. Nope still no go. Compression test shows 150 - 157 per piston.
So I leave the wires off the map sensor for now. How ever wiether it be the same problem or another when the motor is cold I start it and it runs no to bad has no power. If i tramp it the motor boggs down how ever it still runs long as I am easy on the gas. Get to a hill I slow right down cause there isn't much power. SO once she is warmed up I then unplug my coolant temperature sensor then she has power. I can light the rear end up and lay down rubber no problem. How ever if I have the coolant temperature sensor unpluged while she is cold and I give it gas she stalls lol.
So generally plug it in drive to the store or so to grab coffee then unplug the sensor and finish off my drive to work. Its anoying. As far as power it still isn't what a 350 should be offering. Also when the motor is cold and and the sensor is plugged in and I tramp it if it doesn't bogg and almost stall after some major hesitation the motor will fire up and roar to like some stupid high rpm but I wont be going anywhere. You would think trany is shot. But doesn't do this when temp sensor is unplugged and motor is warmed up.
I have replaced the coolant temp sensor. Knock sensor. wires. Plugs. Cap and rotor, Egr Valve hoses. Spark Module. Altenator. Selanoidvalvue. Belt. Condensor. Rad. O2 Sensor. Fuel Filter.
On a diagnostics check I get code 43 Lean Exhaust.

The next thing I want to replace is the fuel pump. AllI guess I need to know is would this cause all this crap?Its on my list to replace anyhow because I have a leak in my gas tank and if im ripping that off i minus well replace the pump and lines at the same time. Any thoughts be very greatfull.

(Note My E break light blinks at me 5short 1 long. I know its tellingme somthing there but know one seems to know what that is about either.

Alright. Thx

 

wow..................argon?

 

Im lost on that one. I dont kow but maybe its time for a new truck.

 

the lean code tells all..she is starving for gas...I think it is the pump,but the pressure needs to be checked to make sure.
Those were bad about the hose on the pump cracking,and letting the gas rain back into the tank

 

Yeah I was thinking it was the Fuel pump most likely. Just always seemed to me that when a fuel pump goes it just goes. Either works or it doesn't. Ill let ya know as I am planning on replaceing it anyhow plus the lines and tank so should take care of the pressure or anthing else Im missing.

As far as buying a new truck well. There aint much on her that aint new now lol. I have only listed things under the hood that I have replaced.lol
Ive learnt a lot from this project truck. It was well worth the money that I have put into it thats for sure just on the learning curve aspect. It will be more worth it when it runs right.

In the end it would of cost me 8k give or take for a truck that works good and looks awsome.
Sure beats 30k for a new truck.
Anyhow. Thanks for the input. Ill let ya's know how I make out.