my truck hard starting

[kpe towing]

hey all fords truck fans i have one for u I have a 1990 ford f250 4x4 auto last month fuel pump went out on block then i put new one in now the truck will start u run for 30 seconds and then die then restart runs for 30 seconds then dies then have to crank for 2 to 3 mins to start then runs very bad then idle goes up and down i have replace fuel pump fuel filter replaced glow plugs glow plug relay etc still does the same thing also it has ats trubo system i neeeed help please this is my baby i tired of spending money i dont have any help will be helpful thanks for taking time to read this also the fuel filter always have alot air in liness bleed the lines then it will start

[jasonr8806]

ok this may sound like i am crazy. last week we had a humvee that came in for a new engine so we replaced it and went to start it up and it had same problem as you are describing. after pulling out the mechanical pump on the block we discovered that the rod that rides the cam and actuates the pump was shorter than the old rod by about .5 inch. If you didn't replace the rod I would check if you installed the pump correctly. when you put a new pump on you have to take that rod out and goop some grease on the end so that when you stick it back up in the engine it stays. the arm on the pump has to go between the rod and the engine case. You know what though i am getting ahead of myself here. that should only be done after you find out if you have fuel pressure. easiest way to do this is go to the valve on the filter housing that looks like a tire valve. check the pressure there. if you arent getting 3-9 psi there is something wrong with your mechanical pump. if you do have pressure there than you have an injection pump problem or obstruction after the filter. you can check injection pump by dissconnecting the return line(rubber hose that goes to the top of the injection pump cover). If you get about a pint of fuel in 30 sec. of cranking the engine over than you have a good injection pump. first check the fuel pressure though cause that will tell you wether it is in your injection pump or mechanical pump. if both all of that checks out ok than check your fuel shutoff solenoid. the way you can do this is by disconnecting the wire that goes into the injection pump top cover right beside the return line. turn the truck to run and connect the wire. when you connect the wire you should hear an audible click. if you don't check if you have voltage to that wire. it should be 24 volts i think. that is what it is on humvees anyway. if you got voltage and you don't hear a click than your fuel shutoff solenoid is bad so you have to pop the cover and replace it. NOTICE, can't say this enough. if you put in a new solenoid you HAVE to check it by connecting the wire and listening for the click. if you don't get a click on a new solenoid than you installed it wrong and you will get a run-away engine. that cover has to be installed so that the solenoid arm doesn't get jammed in the linkage inside the pump. good luck


hope this helps, keep me up on what you find out
jason

[swervn69]

Sounds like you have an air leak in the fuel system. Are there any leaks around the injector return caps? This is a common place for air to get into the system. Also check the inlet hose from the frame to the fuel pump for cracking.

[chuckster57]

Originally Posted by jasonr8806

ok this may sound like i am crazy. last week we had a humvee that came in for a new engine so we replaced it and went to start it up and it had same problem as you are describing. after pulling out the mechanical pump on the block we discovered that the rod that rides the cam and actuates the pump was shorter than the old rod by about .5 inch. If you didn't replace the rod I would check if you installed the pump correctly. when you put a new pump on you have to take that rod out and goop some grease on the end so that when you stick it back up in the engine it stays. the arm on the pump has to go between the rod and the engine case. You know what though i am getting ahead of myself here. that should only be done after you find out if you have fuel pressure. easiest way to do this is go to the valve on the filter housing that looks like a tire valve. check the pressure there. if you arent getting 3-9 psi there is something wrong with your mechanical pump. if you do have pressure there than you have an injection pump problem or obstruction after the filter. you can check injection pump by dissconnecting the return line(rubber hose that goes to the top of the injection pump cover). If you get about a pint of fuel in 30 sec. of cranking the engine over than you have a good injection pump. first check the fuel pressure though cause that will tell you wether it is in your injection pump or mechanical pump. if both all of that checks out ok than check your fuel shutoff solenoid. the way you can do this is by disconnecting the wire that goes into the injection pump top cover right beside the return line. turn the truck to run and connect the wire. when you connect the wire you should hear an audible click. if you don't check if you have voltage to that wire. it should be 24 volts i think. that is what it is on humvees anyway. if you got voltage and you don't hear a click than your fuel shutoff solenoid is bad so you have to pop the cover and replace it. NOTICE, can't say this enough. if you put in a new solenoid you HAVE to check it by connecting the wire and listening for the click. if you don't get a click on a new solenoid than you installed it wrong and you will get a run-away engine. that cover has to be installed so that the solenoid arm doesn't get jammed in the linkage inside the pump. good luck


hope this helps, keep me up on what you find out
jason

Just a bit of info: the IDI fuel pump does not have the pump "rod" like a SB chevy. the "arm" of the pump rides on a rotating "lobe" and if you are installing a new style (longer arm) pump there are specific insructions to make sure the pump is installed properly. If there is pressure at the Schrader valve in the filter head then the clear line test is needed to check for air intrusion. Volatage to the Fuel shutoff sol is 12VDC not 24..batteries are connected in PARALLEL (+ to + / - to - ) for more reserve power and starting amps.

[Eric @ ATS]

Any luck?