99 7.3 idle problem
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99 7.3 idle problem
Hello everybody, I am new here. I just have a question I hope somebody can help me with. I have a 99 F-350 with the 7.3. I recently got some bad fuel that made my truck run like crap. I dropped the tank and cleaned it, replaced the fuel pump, and have replaced a couple of fuel filters. My truck ran well for a while but now I a slight loss of power and it doesn't seem to want to idle. I had a check engine light come on and the code was P1211. I looked this up and it says the injector pressure sensor above/below normal. Any ideas on how to fix this? Any help would be greatly appreciated. Don't want to take this truck to the shop since my 04 6.0 is in there with a bad head gasket right now. Thanks in advance.
Post Fiend
Joined: Mar 2007
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From: Texas
Welcome to FTE. I guess the first question is did you make sure the screen on the fuel pick up tube was clean when you had the tank down?
Check you're engine oil level. Make sure the oil is full and isn't too old. Clean full oil of the proper grade is vital to a good running engine. If the oil checks out good try unplugging your ICP and see if the idle smooths out. When you unplug it look to see if there is oil in the connector. If unplugging the ICP makes it idle smooth, and plugging it back in makes it idle rough, you probably need a new sensor.
The ICP is located towards the front of the drivers head and looks like this
Check you're engine oil level. Make sure the oil is full and isn't too old. Clean full oil of the proper grade is vital to a good running engine. If the oil checks out good try unplugging your ICP and see if the idle smooths out. When you unplug it look to see if there is oil in the connector. If unplugging the ICP makes it idle smooth, and plugging it back in makes it idle rough, you probably need a new sensor.
The ICP is located towards the front of the drivers head and looks like this
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Thanks for the info. I changed my oil when I did everything else to the truck. I am using Rotella 15-40. I am in southern AZ and the temps have been running mid 90's in the day and mid to high 40's at night. I tried unplugging the ICP and it made no difference in the idle. Before I picked up the bad fuel, I had an injector knocking; I am wondering if it gave out totally.
Post Fiend
Joined: Mar 2007
Posts: 26,966
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From: Texas
If you're worried about a bad injector, you can either have an injector buzz test performed by someone with a PSD capable scanner or here's a quote from another thread describing how to watch for oil from the injector to visually check them yourself.
Here's a link to the thread I pulled the quote from. https://www.ford-trucks.com/forums/7...-mechanic.html
Ok, Now that i have read all or most of the posts i'll put in my few ideas.
I noticed he said it has 260k miles. Now my thoughts are directly to injectors or glow plugs.
Your first thing you could do is with a multi meter check to make sure the glow plug relay is working when it should be. Take the black probe of the meter and put it on a ground and touch one side of the relay with the red probe. The one side of the relay with always have 12v. Now make sure the truck is cold (sat over night) have the meter laid out and turn the key on. Run back to the engine bay and do the same thing as above only put the red probe on the other side of the relay and read the voltage. Now quickly read what your batts are also. If they are very close to the same +/- .5 volts the relay should be fine.
Next step. Now that you know the GP's are getting power you want to check to see if they are functioning properly. So look at the middle of the valve covers on the top side you will see a plug. take the black probe and hold it on the center pin, take the red prob and hold on the most outside pin. your reading OHMS it should be around 1 (https://www.ford-trucks.com/forums/4...ke-thread.html) there's some more info. Read post 4 it tells what pins are the Glow plugs.
Now if all of these check out fine. And i think they will. You will want to pull the valve covers.
There are 2 ways you can do this. 1 way is to have a AE and be able to run an injecter buzz test while the engine is cold. But no everyone has access to a 400 scan tool. So i did it my way.
Way #2. While the Valve covers are off and the truck is cold just like it is when you have starting problems you can start the truck. Starting the truck with no valve covers will not harm anything, just make sure that everything is away from the moving rocker arms and that nothing is laying on the cowl that will fall off into the open heads. Now that the truck is running you will be able to see oil coming out of the spouts of each injector (or lack of). The spouts are on the top side right at the pushrods. Now here you want to look for injectors that do not have any oil coming out of them, this means that injectors is NOT firing. After you have let it run long enough to take not on the injectors that are not firing check the conections on those injectors and try again. If i was a betting man, I would be putting a fairly large sum on the fact that your injectors are still original and are just worn out of specs. Meaning that when your engine comes up to temp, the injector expands decreasing the clearance and allowing the seloniod to pick up the popit and allowing it to fire.
My reasons for the strong feelings about the injectors are that just this spring i finally located my miss when cold. I had the covers pulled off so i could borrow the harness for some IDM testing and i figured for grins i would see if i could find an injector that wasn't firing. And i did. So I pulled the injector and put it on the IDM project controller. I tried to run it at room temp and it wouldnt' fire, Hit it with the heat gun for a min or 2 and BAM it was firing.
If you choose to take the route that most guys in here do when it comes to their trucks, if you want a mechanic you can rely on more than anything else ever just look right in the mirror
Ps, I appologize if i was too into the minor things with locations as i don't know your background on these trucks and i don't by any means want to offend you.
Ps X2
I also go with Kwik's feelings. While your in there make sure everything is tq'ed to where it should be before you put it all back together. Even if its just for a few days to drive it while your waiting for parts or deciding how your going to tackle the situation.
I noticed he said it has 260k miles. Now my thoughts are directly to injectors or glow plugs.
Your first thing you could do is with a multi meter check to make sure the glow plug relay is working when it should be. Take the black probe of the meter and put it on a ground and touch one side of the relay with the red probe. The one side of the relay with always have 12v. Now make sure the truck is cold (sat over night) have the meter laid out and turn the key on. Run back to the engine bay and do the same thing as above only put the red probe on the other side of the relay and read the voltage. Now quickly read what your batts are also. If they are very close to the same +/- .5 volts the relay should be fine.
Next step. Now that you know the GP's are getting power you want to check to see if they are functioning properly. So look at the middle of the valve covers on the top side you will see a plug. take the black probe and hold it on the center pin, take the red prob and hold on the most outside pin. your reading OHMS it should be around 1 (https://www.ford-trucks.com/forums/4...ke-thread.html) there's some more info. Read post 4 it tells what pins are the Glow plugs.
Now if all of these check out fine. And i think they will. You will want to pull the valve covers.
There are 2 ways you can do this. 1 way is to have a AE and be able to run an injecter buzz test while the engine is cold. But no everyone has access to a 400 scan tool. So i did it my way.
Way #2. While the Valve covers are off and the truck is cold just like it is when you have starting problems you can start the truck. Starting the truck with no valve covers will not harm anything, just make sure that everything is away from the moving rocker arms and that nothing is laying on the cowl that will fall off into the open heads. Now that the truck is running you will be able to see oil coming out of the spouts of each injector (or lack of). The spouts are on the top side right at the pushrods. Now here you want to look for injectors that do not have any oil coming out of them, this means that injectors is NOT firing. After you have let it run long enough to take not on the injectors that are not firing check the conections on those injectors and try again. If i was a betting man, I would be putting a fairly large sum on the fact that your injectors are still original and are just worn out of specs. Meaning that when your engine comes up to temp, the injector expands decreasing the clearance and allowing the seloniod to pick up the popit and allowing it to fire.
My reasons for the strong feelings about the injectors are that just this spring i finally located my miss when cold. I had the covers pulled off so i could borrow the harness for some IDM testing and i figured for grins i would see if i could find an injector that wasn't firing. And i did. So I pulled the injector and put it on the IDM project controller. I tried to run it at room temp and it wouldnt' fire, Hit it with the heat gun for a min or 2 and BAM it was firing.
If you choose to take the route that most guys in here do when it comes to their trucks, if you want a mechanic you can rely on more than anything else ever just look right in the mirror
Ps, I appologize if i was too into the minor things with locations as i don't know your background on these trucks and i don't by any means want to offend you.
Ps X2
I also go with Kwik's feelings. While your in there make sure everything is tq'ed to where it should be before you put it all back together. Even if its just for a few days to drive it while your waiting for parts or deciding how your going to tackle the situation.
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I have put about 250 miles on it. My fuel economy has gone to crap, getting about 10.5 now, was getting about 20.5. The engine seems to have less power than it did before and sitting at an idle, when you push the accelerator, it seems really slow to respond. I am at a loss.
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Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
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From: Grand Lake, La.
Chris, you don't think it would be a fuel issue?
Do you hear your fuel pump run when you turn the key on? Did you open your water release valve on the bowl and turn the key on to make sure you have a good fuel flow? Can you check your fuel psi?
Do you hear your fuel pump run when you turn the key on? Did you open your water release valve on the bowl and turn the key on to make sure you have a good fuel flow? Can you check your fuel psi?
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I do hear the fuel pump come on when I turn the key on; I replaced the pump less than a week ago. I do not have a way to test the fuel pressure and to answer an earlier question, I did make sure to clean the screen in the pickup tube that is attached to the sending unit. Last night I tried putting some sea foam injector cleaner in the filter bowl to see if that would help and it has not. I drove the truck about 70 miles this morning after I put that stuff in.
Post Fiend
Joined: Mar 2007
Posts: 26,966
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From: Texas
If you turn the key on and open the drain lever, how strong does the spray out? It should be a good, strong, steady stream. You can also disconnect the fuel line from the back side of the fuel pump and blow some compressed air (20 psi or so) backwards into the fuel tank to make sure there's not an obstruction in the pick up tube. Make sure to remove your fuel cap if you do this. You can observe how well fuel flows out the hose before and after the shots of air to see if there's any noticeable difference.
What made you decide to replace the fuel pump in the first place? Let's make sure we don't skip over any info that might be useful.
What did you use to pull the 1211 code from the truck? Does it have the capability to look at any live data? Did the code come back after you cleared it?
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I have a code reader that I used to pull up the code. That is all it can do, it has no diagnostic ability other than getting the codes out of the computer. I cleared the code once, it went away for a while then it came back again. The second time it came back it also had a code for low boost pressure. I cleared both codes and have not seen either since. I changed the fuel pump because I thought it was a fuel delivery problem and not giving the engine enough fuel. That was $200 that didn't need to be spent. I was just throwing parts at it. I have not opened the drain valve and turned the key on to see how much fuel comes out. I have opened the valve to drain the bowl with the key off. How much stronger should the flow be with the key on? When I dropped my tank, I blew the line out from the fuel pump back to the tank side. I did this before I put the clean tank back in place. I don't know if I have a blockage somewhere between the fuel pump and the injectors, which is guess is totally possible. My fuel filter housing did have a significant amount of junk in it prior to me dropping the tank. I cleaned it out and put a new filter in it after I was sure I was running clean fuel.
Post Fiend
Joined: Mar 2007
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From: Texas
Junk in the fuel bowl is never a good thing. Do you know where the fuel pressure regulator (on the side of the fuel bowl is) Maybe you got some junk in there that is keeping you from building the correct fuel pressure.
With the key on the fuel coming out the drain hose should be a very noticeable difference.
I'm not sure about why you would get a boost pressure code. Do you remember what it was?
With the key on the fuel coming out the drain hose should be a very noticeable difference.
I'm not sure about why you would get a boost pressure code. Do you remember what it was?
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I do know where the fuel pressure regulator is. I didn't even think to check that. I have to access it by taking the filter housing off correct? The code was a P1247, I believe the book said that the code was turbo boost pressure low. I just figured that would make sense if the injectors weren't getting enough fuel to give adequate combustion. The truck does not smoke at all when it is at idle or when you are driving at highway speeds. Occasionally it will give a puff of black smoke when you get on it.
Lead Driver
Joined: Jun 2007
Posts: 7,760
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From: Hampton, Maryland.
When it comes to poor performance, I don't usually believe in coincidences too much, that being said, with the drop in economy, the boost numbers being low, all the filters being new, the fuel pump being new, and the tank cleaned out very well, you might have a boot that is loose. Have you checked all your IC boots? I don't mean to say that this might not still be a fuel injector issue, or some other fuel related one, but you just might want to check the IC boots to make sure you don't have a leak somewhere. I don't mean to send you off on a tangent, but sometimes it could be something all together different than the direction you are currently looking, and boost problems will cause the issues you are having too.
I also would take the intake tube off and look at the blades on the turbo. How many miles does your truck have?
I also would take the intake tube off and look at the blades on the turbo. How many miles does your truck have?