Trouble starting
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Freshman User
Joined: Nov 2010
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Trouble starting
I have a 96 f-250 7.3. Replaced the glow plugs and gpr about 6 months ago. And just recently started having trouble.starting in the mornin. I have to crank on it for bout 20 seconds nefore it starts and when it does it sounds sounds like it wants to die for about the first 20 seconds. Cud the gp's be going bad already for wud I have a faulty gpr?
Second found a sensor on my gas pedal that I cant find anywhere. Ford says they dont have it. Wont even tell me what it is. My truck when is started and I hit the accelerator has no response. I changed the pedal position sensor but there is another sensor. Any idea what it is or where I can find one?
Second found a sensor on my gas pedal that I cant find anywhere. Ford says they dont have it. Wont even tell me what it is. My truck when is started and I hit the accelerator has no response. I changed the pedal position sensor but there is another sensor. Any idea what it is or where I can find one?
Lead Driver
Joined: Aug 2006
Posts: 5,259
Likes: 17
From: Gambrills
WELCOME TO FTE!!!
1996 Bronco/F-Series Workshop Manual
Tips - Idea - Hints
Sounds like how long do you have the truck in the "ON" position before you crank? The light does not represent how long the GP's are on for. When it is cold the GPR stays engaged for 2+ minutes. I would keep they key in the "ON" position for 1+ minute and see what you have then. unrelated- make sure you FPR screen is clean!
I can't help with the pedal, sorry. Someone else knows though.
again WELCOME!
1996 Bronco/F-Series Workshop Manual
Tips - Idea - Hints
Sounds like how long do you have the truck in the "ON" position before you crank? The light does not represent how long the GP's are on for. When it is cold the GPR stays engaged for 2+ minutes. I would keep they key in the "ON" position for 1+ minute and see what you have then. unrelated- make sure you FPR screen is clean!
I can't help with the pedal, sorry. Someone else knows though.
again WELCOME!
Lead Driver
Joined: Oct 2003
Posts: 8,476
Likes: 37
From: Madison, WI
You cOULd have a faulty GPR or faulty GPs. What brands of relay and plugs did you get?
GPR test - turn the key to RUN and measure the voltage between the two "big" terminals on the relay. If it's more than 0.3V, voltage drop is excessive and the relay is suspect. You can also measure this by measuring the voltage from the "always hot" big terminal to ground, and then measure the voltage from the "not always hot" big terminal to ground, and the _difference_ is the voltage drop.
GP resistance test - disconnect each UVCH connector, one at a time. Each connector feeds two cylinders; the outboard pins feed the two corresponding glow plugs. Measure the resistance, one at a time, between each outboard pin and a ground. It should be about 1 ohm.
Other "sensor" (really a switch) on the go-pedal is the idle confirmation switch. Unlikely it's failed, but easy enough to test like any other switch. Some fellas have found that the switch doesn't open until you move the pedal a considerable amount; this makes the PCM keep the truck at idle over that first bit of pedal movement. It's commonly called "dead pedal". The fix is to adjust the switch (bend its mount, IIRC) so it clicks off "sooner" in the pedal travel. The risk is that if you over-adjust, the switch will never be closed with the pedal at idle, and that'll confuse the heck out of the PCM.
GPR test - turn the key to RUN and measure the voltage between the two "big" terminals on the relay. If it's more than 0.3V, voltage drop is excessive and the relay is suspect. You can also measure this by measuring the voltage from the "always hot" big terminal to ground, and then measure the voltage from the "not always hot" big terminal to ground, and the _difference_ is the voltage drop.
GP resistance test - disconnect each UVCH connector, one at a time. Each connector feeds two cylinders; the outboard pins feed the two corresponding glow plugs. Measure the resistance, one at a time, between each outboard pin and a ground. It should be about 1 ohm.
Other "sensor" (really a switch) on the go-pedal is the idle confirmation switch. Unlikely it's failed, but easy enough to test like any other switch. Some fellas have found that the switch doesn't open until you move the pedal a considerable amount; this makes the PCM keep the truck at idle over that first bit of pedal movement. It's commonly called "dead pedal". The fix is to adjust the switch (bend its mount, IIRC) so it clicks off "sooner" in the pedal travel. The risk is that if you over-adjust, the switch will never be closed with the pedal at idle, and that'll confuse the heck out of the PCM.
