problems starting that requires carb cleaner to start

[bobberguy]

Thank you to anyone with advice. I have a 93 sport it takes carb cleaner or starter luid to get it running but once you get it running you to play with the gas for 15 minutes to keep it running if it will stay running once it finally smoothes out and idles on its own and revs up clean it runs like a champ untill u turn it off. I have replaced the fuel pump fuel filter ive taking the whole top half of the motor apart and cleaned the fuel injecters were cleaned and spray good if anybody has any ideas i havent tried they woulx be much appreciated thanks for the help.

 

[Big_Stig352]

Check Your ECU. That Was My Problem.

(by check the ecu i mean open it up and check the caps. one of them is responsible for priming it i think)

 

[MrShorty]

If it starts on carb cleaner, that suggests a fuel problem. Even though you have replaced those parts, I'd probably start by putting a fuel pressure gauge on it to see if the fuel system is doing what it should.

 

[bobberguy]

I have its pumping 35 psi to the fuel rail. Ill try the ecu this after noon are you saying the terminals might just be dirty were the wires connect?

 

[bobberguy]

Oh i forgot to mention i had to straight wire the fuel pump because as soon as you put a fuel pump fuse in it blows the fuse

 

[Big_Stig352]

no im saying take it out of the car open it up and look at the capacitors, there should be 3 of them( there were in mine) (capacitors look like little cans youll see them) and if the underside of them is burnt or rusted (all 3 of mine had completley unsodered themselfs) its your ECC/

 

[bobberguy]

Just pulled the ecu all one of the capistors has a broke lead is would you think thats repairable or should i just replace it

 

[bobberguy]

All of them are rusted thoughon the bottom side

 

[bobberguy]

so i tried a different ecu samething it started on the carb cleaner would stay running with me holding the gas at medium rpms for about 20 secondsl then it would just try to die if i pumped the gas it would stay running crapy at around 1000 rpms then die i purged the fuel system but dont have a gauge it looked pretty weak just kinda poured out didnt spray at all it's been awhile since i put a fuel pressure guage on it thought i had one can't find it. if it does have low fuel pressure is there anything else would give it low fuel pressure seemed like the spark was fine. it has been a long time since the truck has ran consistly as a daily driver thank you for anybodys help.

 

[bobberguy]

Can any think of any sensors that might cause some stupid problems like this?

 

[MrShorty]

In post 4 you said it had 35 psi fuel pressure, but I guess that was old data?

if it does have low fuel pressure is there anything else would give it low fuel pressure

There aren't a lot of common causes of low pressure. I had a bad pump (brand new) that would get too hot on a hot day and start to shut down. I've heard of cases where the rubber hose in the pump assembly that goes from the pump to the top of the assembly would be loose and not allow enough pressure to build up. The fuel pressure regulator is responsible for maintaining the correct pressure -- if it gets stuck open the pressure can run too low. A clogged filter or other restriction in the fuel line would cause low pressure at the rail.

At this point, I would definitely encourage you to find your pressure gauge and determine if the fuel system is up to snuff.

 

[bobberguy]

Ok so i broke down and bought a new fuel gauge. With the key on remembering that the fuel pumpalways runs the most pressure it read was 15 psi. Is there an orifice any where in the system thought could be clogged? You mentioned something about a hose your talking about pulling the fuel tank again arent you. I pulled the fuel return line off the regulator and there is no gas coming out of it so im not thinking it is bad. Oh also something new i found is that parts of my wiring harness have melted to the headers. It was mostly the plastic counduit that got messed up a few wire burnt the insalation but the wire it self appears to be in tact. Is there anything there that might cause low fuel pressure with a straight wired fuel pump

 

[MrShorty]

Is there an orifice any where in the system thought could be clogged?

The most likely place I can think for clogging is the filter. You say that you recently replaced the filter, so it seems unlikely that it would be that clogged up, unless there is a lot of crap in the tank. Filter is a lot easier and cheaper than dropping the tank, so it might be worth the effort to check the filter. While you have it disconnected, you might see if you can find or rig a way to measure how much pressure the pump is generating before the filter.

You mentioned something about a hose your talking about pulling the fuel tank again arent you.

Yes, the hose I had in mind here is inside the tank.

few wire burnt the insalation but the wire it self appears to be in tact. Is there anything there that might cause low fuel pressure with a straight wired fuel pump

The only electrical part of the fuel system is the fuel pump, so the only way a burnt wire would be contributing is if it was a fault in the fuel pump circuit that was limiting current to the fuel pump. If the harness in question is not carrying part of the fuel pump circuit, then I don't see anything here contributing to the problem.

 

[bobberguy]

Thank you for helping me out with this any ides on rigging something up to measure before the filter