Wont start without pressing on accelerator

[jordanecoblasting]

Hello all,
I am having trouble starting my truck. When I try and start it, it does not start without me pushing on the accelerator for about 30 seconds. When I do not do this, it starts and immediately dies. I have changed the fuel pump, rotor, cap, plugs/wires, evap purge valve, water pump, IAC, TPS, MAP, o2 sensor and cleaned out the throttle body. Any ideas on what to do next? My truck is a 99 ram 2500 5.9 v8 gas 360. Thanks in advance for your help.

 

[jws123]

even tho you replaced the fuel pump turn the key on 2-3 times priming the pump and the go to start it if it fires right up its the fuel issue.

 

[jordanecoblasting]

Could a bad fuel pump also make my engine run rich? I am getting code po172

 

[huntergreen]

Have you checked your air filter ?

 

[jordanecoblasting]

Yeah unfortunately air filter is not the problem

 

[Tank Guy]

I have a 2002 Dodge Neon with a similar issue. Before you start laughing, hear me out. In my case I have a failed check valve in the fuel line coming from the fuel tank up to the fuel manifold that carries the fuel to each of the injectors. Because of this when I shut off my engine the fuel in that line immediately begins draining back into the fuel tank. A properly working check valve is supposed to prevent that. Since replacing the check valve in my case requires dropping the fuel tank, I get around it by turning the key on and off several times so the boost pump can push fuel up to the engine. In your case, if your check valve has failed allowing the fuel to drain out of the line, there may still be enough sitting in the manifold that delivers fuel to the injectors to allow the engine to start, but that fuel would be quickly consumed, followed by an air pocket causing the engine to die. That air pocket would then be quickly pushed out by the fuel coming off the boost pump, thus allowing the engine to run again. It's just a thought but worth looking into.

 

[jordanecoblasting]

Thank you for your response I will look into it tomorrow.

 

[jordanecoblasting]

My mechanic figured out what the problem was...

First my mechanic put on a new IAC. Did not solve the problem so he put the old one back on. Then my mechanic cleaned out the throttle body. This didn't solve the problem either. Then he put the new IAC back on after having cleaned the throttle body and it started right up..... So the problem was a combination of the IAC being bad and the throttle body being dirty.