The Diesel Stop banner

1 - 20 of 32 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter #1
Hello. I've read numerous threads already about this issue but feel like a may be missing something. I have a 2003 f350 7.3 with 209000 miles on it. I'm in Alaska its about 50 or 60 degrees at the moment. Tach doesn't move when cranking. The truck will not start unless plugged in. Rough idle when it does start until it gets to operating temp then runs fine. No change when I unplug the ICP and looks to have been replaced before. Oil change ~2000 miles ago with 15w40 and oil level look good. Changed fuel filter and filled the tank up and put Lucas injector cleaner and half a court of automatic transmission fluid in with it to clean injectors. Passenger side valve cover has had new pluggin. This truck is giving me a headache. Please help. Thanks in advance.
 

·
Super Moderator
Joined
·
25,419 Posts
Your '03 won't move the tach when cranking. That only happens on '01 and earlier trucks.

If you have to plug in to start at 50-60 degrees, you need to look into your Glow Plug system. Check the Hard/No-Start Link in my signature. It should fire right off at well below 50, without plugging in. The glow plugs should still be active after the engine is running for a bit, with length depending on oil temperature.

Rough idle may be because of worn injectors, but don't condemn them yet. They should last longer than your current mileage. I would avoid putting too much in the way of additives in your fuel. Maybe something like PowerService or Standyne, but ATF probably won't help clean your injectors. It's possible that your injectors have reduced clearance on the armature plates.

If you're in the Anchorage area, we could hook it up to AutoEnginuity and see what's up. An injector buzz test with a cold engine takes just a few minutes and would give you some indication of injector condition.

Welcome to TheDieselStop
 

·
Registered
Joined
·
5,307 Posts
The electrical issue to first resolve is checking the glow plug relay system. The big relay behind and the passenger side of fuel filter housing should have less than .5V if you put DC voltmemeter leads on the 5/16" posts (1/2 nut) with cold engine and then watch voltmeter when someone turns ignition on and the glow plugs are powered through the relay. If the voltage difference is more than .5V then the relay is bad and glow plugs are not working. If the really checks good then it might be a good idea to get compression checked. I have diagnosed a bunch of 7.3 poor cold start and poor idle as dusted engines from poorly fitted air filters and/or cracked or misfitted hoses from air filter to turbo. The turbo compressor blades that are visible with the air inlet hose off turbo will often tell the story. The blades should have a blunt forward edge and the tip of the blades would be a sharp 90 degree where blade edge is at turbo housing. When the blades cut through unfiltered dirty air the blade edge gets sharp and worn and the 90 degree cut of the end of each blade gets rounded off. The sensors on the engine are injection control pressure on the LH cylinder head at front top, oil temp sensor, and the exhaust back pressure sensor. ICP sensors are known failures but usually poor running will also cause the sensor to leak oil into electrical connector. Oil temp is not a drivability issue cause as it is the sensor used to shut down the back pressure control damper and fast idling when the oil temp gets warm with warm engine. Not a cause of rough idle. Cam position sensor down to the right and above (passenger side) crank pulley can cause start and idle quality problems but not usually temp related. The cam position sensor was subject to a recall and likely has been replaced but I have seen the update ones installed 10+ years back fail.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #5
When you turn the key you can hear the glow plug relay click. I don't know about the glow plugs but the relay seems good. The previous owner said he had the relay and glow plugs changed around 6 months ago. I will look at the turbo and see if I can see any wear on the blades.
 

·
Registered
Joined
·
1,140 Posts
if you have a digital volt meter you can check the glow plug relay and you can ohm out the glow plugs. you are going to have to actually test some things rather than going off hearing.
 

·
Premium Member
Joined
·
4,001 Posts
Follow the instructions in Post 2 from KLHanson to test your GP system.

Always replace electrical components with Motorcraft.

Not all scanners will read Ford codes.
 

·
Registered
Joined
·
120 Posts
My 2cts is try changing the engine oil temp sensor, $20 from Motorcraft, EOT sensor DY-961 or Part #:*12A648 and a 5 minute job. I fought the opposite problem of surging when the engine warmed up. Replaced the EBV, ICP, cleaned the EBP twice. Spent hundreds of $$ and several months on it and still had the problem. Then someone on this forum mentioned the EOT and the truck has run perfect since. It may not be your problem but it's cheap and easy to try. Engine oil temp is an input on glow plug operation.
 

·
Super Moderator
Joined
·
25,419 Posts
My 2cts is try changing the engine oil temp sensor, $20 from Motorcraft, EOT sensor DY-961 or Part #:*12A648 and a 5 minute job. I fought the opposite problem of surging when the engine warmed up. Replaced the EBV, ICP, cleaned the EBP twice. Spent hundreds of $$ and several months on it and still had the problem. Then someone on this forum mentioned the EOT and the truck has run perfect since. It may not be your problem but it's cheap and easy to try. Engine oil temp is an input on glow plug operation.
I doubt that the EOT sensor is the problem, but it's a possibility. An easy check is to unplug it and try starting. Without seeing a signal from the EOT sensor, the PCM will default to "cold oil" while starting, and "hot oil" when running. EOT is an input on injector timing, to compensate for cold oil conditions, which tends to reduce the pressure delivered to the injectors.
The EOT is an input to GP operation - if the oil is hot enough, the GP relay won't be activated at all. I recall that the temp is ~140F.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #11
Update. Changed the GPR and no change. Once the key is turned on then I am getting 0 to .1V on the big posts on the GPR. That should mean that the relay itself is working correctly? The glow plugs themselves should be getting power but may not necessarily be working?
 

·
Registered
Joined
·
20 Posts
Discussion Starter #12
Once plugged in it will start right up but had a little shake to it. Almost like a miss. But if I drive it down the road and get on the throttle a little then it smooths right out. It doesn't even have to be warm. Possibly excess fuel on the cylinders being burned off?
 

·
Super Moderator
Joined
·
25,419 Posts
If you're getting that little voltage drop across the two big lugs on the GPR, that could easily mean that most of your glow plugs are burnt out. Check the Hard/no start link in my signature for how to check the glow plugs. A glow plug relay may pull in, but not make good connection. That would be indicated by a high voltage drop between the two posts while activated.
 

·
Super Moderator
Joined
·
25,419 Posts
Measuring the voltage between the two posts is dependent on the resistance of the contacts on the relay. But it also depends on how much load is on the circuit (how many glow plugs are working). A different test is to measure between the post with the brown and yellow wires on it and a ground point on the engine or the battery ground post. With that measurement, you can tell for sure if the relay is making contact if you get close to battery voltage. If none of your glow plugs are working, the measurement will be the same as battery voltage because there will be no current running through the circuit.

You can also measure the resistance across each glow plug by disconnecting the outside valve cover connector. That procedure is outlined in the thread linked below.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #16
Okay so the voltage between to two larger posts should stay around 12.5~ with the key on and off? And I saw in one of the previous replies that a voltage drop of anything more than .5 means that my glow plugs aren't working.

Btw thank you for your input
 

·
Registered
Joined
·
20 Posts
Discussion Starter #17
Update. So I was wrong in my previous post. The big post opposite of the constant has 11.5V when the key is turned on and slowly climbs to 11.9 over a few seconds.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #18
Update. So I was wrong in my previous post. The big post opposite of the constant has 11.5V when the key is turned on and slowly climbs to 11.9 over a few seconds.
 

·
Premium Member
Joined
·
4,001 Posts
Did you follow the link “No Start” in KLHanson’s signature?

That eliminates any guesswork.

It sounds like you may have some GPs that need replacing but the only way to test is using those instructions in “No Start”.

Just to get you thinking of parts, you will want to stick with Motorcraft brand GPs and it might be worth doing all 8 if you are getting in there since they are only $9/each.

If you need a new GPR, then check out the Stancor-White Roger. Its big and outlasts the others based on the feedback forum.

Can be found here:

https://www.dieselorings.com/16-009-white-rodgers-stancor-586-902-monster-glow-plug-relay.html

The “No Start” instructions will tell you what needs replacing.
 
1 - 20 of 32 Posts
Top