A little diagnostic help please!
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From: Dongola, IL
A little diagnostic help please!
I am diagnosing hard cold starting on a 2002 7.3L The cust. said for me to change the GP, I did not reccomend changing them, he just said he wanted them changed. No diff. in cold start. It will start after cycleing the plugs 2 or 3 times, and them start with a cloud of white smoke (air temp around 40 degrees) . It also has a cackaling sound while running that seems to be coming from the driver's side of the motor.
My question is: if he has a (or possibly more than one) bad injector, what are some ways to determine that? I have AE, and it passes a CCT, there are no codes, and the injector buzz test sounds OK, I think.
I thought about trying a laser thermometer on the manifold right after a cold start to see if I can find a problem that way...
BTW, the truck has 167,000 miles on it.
Am I on the right track? or is there something I am totally missing?
My question is: if he has a (or possibly more than one) bad injector, what are some ways to determine that? I have AE, and it passes a CCT, there are no codes, and the injector buzz test sounds OK, I think.
I thought about trying a laser thermometer on the manifold right after a cold start to see if I can find a problem that way...
BTW, the truck has 167,000 miles on it.
Am I on the right track? or is there something I am totally missing?
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From: Dongola, IL
I am pretty sure it is not the relay, because the more I cycle the glow plugs, the better it starts. If the relay was bad, I don't think it would start at all.
Thanks for the input!
Thanks for the input!
Hotshot
Joined: Jun 2007
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From: Austin, TX
Does it idle rough then once it warms up a bit it smooths out and runs fine?
Pull the valve covers off and then do a cold start. Check for oil discharging from all injectors. Probably have a few not firing, but when it warms up they start firing again.
Pull the valve covers off and then do a cold start. Check for oil discharging from all injectors. Probably have a few not firing, but when it warms up they start firing again.
Senior User
Joined: Oct 2008
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From: Loganville,GA
lol.. Well my Input is not worth too much, I am still new in this Area of the Forums. But I have had the Problem you are talking about and my GPR was not cycling all the time If any. I replaced it and had much quicker starts. Its such a Cheap part and if it has never been replaced its not a bad idea to replace it. But it could be a Few things, just throwing one out there..lol.
Elder User
Joined: Aug 2005
Posts: 566
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From: New Jersey
Almost sounds like a fuel pressure problem. Cackle is caused by fuel pressure variations. I'm wondering if the IPR is working right or if something in the fuel system is out of whack and the truck's PCM is trying like hell to get it running. Just a thought.
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From: Elkhorn, WI
Turn the key on and run out and lay a screwdriver across the 2 big posts on the gpr and I bet it starts the first cycle. Cycling it 3 times would make no difference if it was an injector or fuel problem. But it would if it was a gpr problem. They start getting corroded and making weak connection inside and the more you cycle it the more juice is heating up the glow plugs
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From: Dongola, IL
Does it idle rough then once it warms up a bit it smooths out and runs fine?
Yes, It misses for 4-5 seconds, and then it starts to smooth out. Once it is warm it runs fine, except for the cackle.
Pull the valve covers off and then do a cold start. Check for oil discharging from all injectors. Probably have a few not firing, but when it warms up they start firing again.
Yes, It misses for 4-5 seconds, and then it starts to smooth out. Once it is warm it runs fine, except for the cackle.
Pull the valve covers off and then do a cold start. Check for oil discharging from all injectors. Probably have a few not firing, but when it warms up they start firing again.
Turn the key on and run out and lay a screwdriver across the 2 big posts on the gpr and I bet it starts the first cycle. Cycling it 3 times would make no difference if it was an injector or fuel problem. But it would if it was a gpr problem. They start getting corroded and making weak connection inside and the more you cycle it the more juice is heating up the glow plugs
Now, Does any body here in the 94-97 forum know the easiest way to moniter fuel pressure on a 2002 truck? or should I ask that in the 99-03 forum?
Thanks guys! You guys are the greatest!
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not sure if this is any help but it confirms my idea on the fuel bowl still being there. http://www.dieselbombers.com/ford-po...-pressure.html
i towed an 02 not too long ago that head just shut off so i gave him a bunch of ideas to look for and while i was messing around with it under the hood i saw it still had a fuel bowl, so it might still have valve to check some were?
i towed an 02 not too long ago that head just shut off so i gave him a bunch of ideas to look for and while i was messing around with it under the hood i saw it still had a fuel bowl, so it might still have valve to check some were?
Postmaster
Joined: Sep 2007
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From: Medford Oregon
Check the relay! With a volt ohm meter put the red lead on one of the big lugs and the black lead on the other big lug. With the key on and relay activated the voltage difference between the two big lugs should read 0.5 volts or less. If it's a lot higher such as 1, 2, 3 volts or more then contacts inside the relay are bad (fried). Simple test and cost nothing assuming you have a volt ohm meter.
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From: Dongola, IL
Check the relay! With a volt ohm meter put the red lead on one of the big lugs and the black lead on the other big lug. With the key on and relay activated the voltage difference between the two big lugs should read 0.5 volts or less. If it's a lot higher such as 1, 2, 3 volts or more then contacts inside the relay are bad (fried). Simple test and cost nothing assuming you have a volt ohm meter.
Attachment 30239.................
Post Fiend
Joined: Apr 2004
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From: Silver Lake Dunes, MI
I took a fuel bowl lid and ground out the fins to accept a brass valve stem in the top. I don't leave it on the truck as its my tester but it works good.
As for the hard start. How are the batteries? Do they test any where close to marginal? I have had a number of trucks that start hard like you say but the batteries test ok but they are on the edge. New Batteries and it starts like a champ. They even sound like the engine cranks over good but between the starter and the GP's its just too much to start well.
As for the hard start. How are the batteries? Do they test any where close to marginal? I have had a number of trucks that start hard like you say but the batteries test ok but they are on the edge. New Batteries and it starts like a champ. They even sound like the engine cranks over good but between the starter and the GP's its just too much to start well.
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From: Dongola, IL
I took a fuel bowl lid and ground out the fins to accept a brass valve stem in the top. I don't leave it on the truck as its my tester but it works good.
As for the hard start. How are the batteries? Do they test any where close to marginal? I have had a number of trucks that start hard like you say but the batteries test ok but they are on the edge. New Batteries and it starts like a champ. They even sound like the engine cranks over good but between the starter and the GP's its just too much to start well.
As for the hard start. How are the batteries? Do they test any where close to marginal? I have had a number of trucks that start hard like you say but the batteries test ok but they are on the edge. New Batteries and it starts like a champ. They even sound like the engine cranks over good but between the starter and the GP's its just too much to start well.
I will look into the battery possibilty. Thanks for thinking of that.
The truck is getting dropped off tommorow, I'll let you all know how it goes and what I find.
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From: Dongola, IL
Well guys, Thanks to your help, I found the problems.
Clogged fuel filter, and totally bad GPR. I ate the cost of the GPR, because I should of checked it before changing his GP (He did just tell me to change the GP, not to diagnose it, otherwise I would have checked the GPR right away) but I should have checked it anyway.
Thanks guys!
Clogged fuel filter, and totally bad GPR. I ate the cost of the GPR, because I should of checked it before changing his GP (He did just tell me to change the GP, not to diagnose it, otherwise I would have checked the GPR right away) but I should have checked it anyway.
Thanks guys!
