96 cold start problems
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From: Redwood Valley, CA
96 cold start problems
I've been having cold start problems with my 1996 powerstroke. Replaced glowplug relay and glowplugs with factory IH parts last winter. This year as soon as cold weather hit it won't start w/o plugging it in. The exhaust backpressure system also stopped working which makes warming it up in the morning a long process. I have looked in my IH service manuals and there is reference to the coolant temp sensor and the barometric pressure sensor being part of the glow plug system. Any insight would help.
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From: Redwood Valley, CA
Also once the truck has been started once it will restart. That is unless I let it sit for at least 6 hours. That happened the other day up in the mountains on thursday, drove it to work in the morning and at the end of the day no start. Plugged it in to my welder generator for an hour and a half no start. It was about 30 degrees out and snowing at about 10,000 feet of elevation. I disconnected the coolant temp sensor and it started, though it had been plugged in for nearly 2 hours at that point.
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Joined: Oct 2003
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From: MICHIGAN
Originally Posted by ftowelding
Glow plug relay shows about 11.8 volts while relay is engaged
Also once the truck has been started once it will restart. That is unless I let it sit for at least 6 hours. That happened the other day up in the mountains on thursday, drove it to work in the morning and at the end of the day no start. Plugged it in to my welder generator for an hour and a half no start. It was about 30 degrees out and snowing at about 10,000 feet of elevation. I disconnected the coolant temp sensor and it started, though it had been plugged in for nearly 2 hours at that point.
I suspect it started because it had been plugged in for 2 hours. It can take 3-4 hours when it's really cold out.
Do like Tim said, next cold start cross out the relay with a screw driver for about 30-60 seconds, jump in the truck and start it up. If it fires right up the GPR is bad. IF it starts up and has a slight miss or a romp, romp, romp you may have 1 or 2 GP's that are weak or bad.
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From: Redwood Valley, CA
There is one thing I left out. When my glowplug system crashed last year I discovered that one of my glow plugs had shorted out and welded itself into the cylinder head. I didn't have the time to pull the heads to remove it so its still in there. I zip tied the wiring harness up out of the way and left it disconnected.
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From: Silver Lake Dunes, MI
Yeah the coolant temp sensor is only for the guage. the PCM has no idea what coolant temp is cause it uses the oil temp sensor. My guess is that your GPR is bad. Did it have 11.8 volts on both big terminals with the key on?
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According to the IH service manual I have the ECM monitors battery charge and uses information from the Engine Coolant Temperature (ECT) and barometric (BARO) sensors to determine the amount of "wait to start" light time and glow plug activation time. The ECM controls the "wait to start" light ON time and the activation of the glow plugs separately. The manual also says that the BARO sensor determines the total run time of the glowplugs. I don't know if the Ford system is the same as IH or different.
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From: Silver Lake Dunes, MI
Ford and IH may use different PCM systems. I know for a fact that the PCM has no idea what coolant temp is. But it does use oil temp and baro for GP on time.
Also if the relay is working (voltage on both sides) then the PCM is commanding it and you either have wiring issue to the GP's or bad GP's themselves.
Also if the relay is working (voltage on both sides) then the PCM is commanding it and you either have wiring issue to the GP's or bad GP's themselves.
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