12 v running rich Fuel Ratio ?
12-17-2005, 07:36 AM
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12 v running rich Fuel Ratio ?
Trying to find some answers to some recent things my truck has been going through! First off my truck lives in California and was bought in Colorado over a year ago. 94 12v 2500 stock. Truck has been running great and have in the last year been going through the truck slowly to get it more mechanically sound. mostly brakes, filters, adjusting valves, changing fluids, general maitenance. in the last month it began to not start before this it would start no problem just turn key over. Then I needed to put my foot into it. at first I thought it was the batteries as they needed to be changed anyway. well this was'nt it. had my mechanic look at it and it was getting air and we put a new lift pump on it and it seemed fine. not to long after this it did'nt want to start easily again. we went through the hoses and checked that the system was not taking in air so that was ruled out. next checked the rpms and they were where they should be.
Anyway I'm not a mechanic and this is what my mechanic thinks may be the problem.
I started using additives in this truck I don't know if they were used prior to my purchase of truck but here is my mechanics guess. that this truck was set up for higher altitude and by using the additives possibly the injectors are cleaner now and that it is getting more fuel and running richer this causing harder starts. He says you can take the truck somewhere where they will adjust the fuel mixture but it can cost a bit and that they don't alway get it right. Also my truck now will start perfectly some days and some days I need to put my foot into it.
The question I guess is maybe I may need to get a new injector pump? or stop the additives and see if the truck will settle in?
I am heading to Baja in 2 weeks and my mechanic thinks I am fine to go but not being a mechanic myself I would like to hear some thoughts solutions or other on this topic.
Anyway any ideas!!!
Hope this all makes sense.
CG
Anyway I'm not a mechanic and this is what my mechanic thinks may be the problem.
I started using additives in this truck I don't know if they were used prior to my purchase of truck but here is my mechanics guess. that this truck was set up for higher altitude and by using the additives possibly the injectors are cleaner now and that it is getting more fuel and running richer this causing harder starts. He says you can take the truck somewhere where they will adjust the fuel mixture but it can cost a bit and that they don't alway get it right. Also my truck now will start perfectly some days and some days I need to put my foot into it.
The question I guess is maybe I may need to get a new injector pump? or stop the additives and see if the truck will settle in?
I am heading to Baja in 2 weeks and my mechanic thinks I am fine to go but not being a mechanic myself I would like to hear some thoughts solutions or other on this topic.
Anyway any ideas!!!
Hope this all makes sense.
CG
12-17-2005, 09:35 AM
#2
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Your truck smokes alot.
these trucks tend to smoke alot more when the air is thinner, there isnt enough air to efficiently burn the fuel on this truck. If you want to have less fuel into the mixture you might want to put your fuel plate back and turn down the starwheel on the truck. Welcome to DTR by the way!
now here is a basic writeup as towards what u can do
https://www.dieseltruckresource.com/...ad.php?t=78573
Please scroll down and read. Even if you simply dont want any power gains, it tells you how you can remove and work with the plate, as well as what some other benefits are of a GSK and so on and so forth. Please read this..
Where is your idle set at? Please put ur truck in the signature so we can know what you have. Your truck with AC on should idle at about 700 RPMS minimum. If it does not idle there, then you need to bump up your idle a smidgen. its a 10 mm box end wrench behind the fuel pump.
The liklihood of your injector pump failure is slim to none, The P7100, although expensive is seemingly bulletproof. If anything your lift pump might be going, but if all you need is a little pedal to start the truck, then its most likely your idle that needs to be bumped up.
If its still hard starting, assuming the batteries, alternator, and starter are all good, its either bad fuel or you are getting air in the rubber fuel return lines on the engine. These can and will usually crack with the heat and can make starting your truck a PITA so to say.
On a more advanced sence, if you are gonna keep this truck you might want to have the injector pump timed as well, perhaps it is another reason why your truck is harder to start.
Best of luck
Rick
these trucks tend to smoke alot more when the air is thinner, there isnt enough air to efficiently burn the fuel on this truck. If you want to have less fuel into the mixture you might want to put your fuel plate back and turn down the starwheel on the truck. Welcome to DTR by the way!
now here is a basic writeup as towards what u can dohttps://www.dieseltruckresource.com/...ad.php?t=78573
Please scroll down and read. Even if you simply dont want any power gains, it tells you how you can remove and work with the plate, as well as what some other benefits are of a GSK and so on and so forth. Please read this..
Where is your idle set at? Please put ur truck in the signature so we can know what you have. Your truck with AC on should idle at about 700 RPMS minimum. If it does not idle there, then you need to bump up your idle a smidgen. its a 10 mm box end wrench behind the fuel pump.
The liklihood of your injector pump failure is slim to none, The P7100, although expensive is seemingly bulletproof. If anything your lift pump might be going, but if all you need is a little pedal to start the truck, then its most likely your idle that needs to be bumped up.
If its still hard starting, assuming the batteries, alternator, and starter are all good, its either bad fuel or you are getting air in the rubber fuel return lines on the engine. These can and will usually crack with the heat and can make starting your truck a PITA so to say.
On a more advanced sence, if you are gonna keep this truck you might want to have the injector pump timed as well, perhaps it is another reason why your truck is harder to start.
Best of luck
Rick
12-17-2005, 10:27 AM
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Thanks for reply Rick.
Truck is not smoking it runs perfectly outside of having the fickel starting . Not getting any air through supply lines. Lines look new and don't show any signs of cracking. Unless a little air would make for fickle starting and then run fine after that?
Your last comment about injector pump timing might be the issue what and who could do this type of adjustment?
I definatley want to keep the truck it is my ship that takes me to Baja. have taken it twice with no problems and outside of this new issue it is in better conditiaon than earlier trips.
94 2500 ctd 4X4
Truck is not smoking it runs perfectly outside of having the fickel starting . Not getting any air through supply lines. Lines look new and don't show any signs of cracking. Unless a little air would make for fickle starting and then run fine after that?
Your last comment about injector pump timing might be the issue what and who could do this type of adjustment?
I definatley want to keep the truck it is my ship that takes me to Baja. have taken it twice with no problems and outside of this new issue it is in better conditiaon than earlier trips.
94 2500 ctd 4X4
12-17-2005, 10:33 AM
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try waiting a few more seconds before the actual start, might give the pump a bit more time to build up a little presure, even if the wait to start light weather is not in effect give the pump some time and see if that helps, if it does it could be a sign of bleed down.
12-17-2005, 10:48 AM
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Pardon me but unless a filter, air or fuel, is clogged up it's impossible for a diesel engine to run rich or lean.
The rubber hoses can look perfectly fine and still suck air especially when the truck is parked. Fuel wants to drain back to the tank but normally can't unless there is a leak.
Same idea as picking up water with straw with your finger over the end.
A bad overflow valve will also cause hard, smoky starting.
The rubber hoses can look perfectly fine and still suck air especially when the truck is parked. Fuel wants to drain back to the tank but normally can't unless there is a leak.
Same idea as picking up water with straw with your finger over the end.
A bad overflow valve will also cause hard, smoky starting.
12-17-2005, 11:05 AM
#6
Like Bill said, Diesels cant run rich like a gas engine.There is no optimum ratio for power like a gasser has of 14.7 to 1 or so. diesels basically take in the same amount of air regardless of how much gas pedal or fuel its getting. There is no throttle plate to regulate it like a carb has. Basically the more fuel the more power. At some point if your supplying mass amounts of fuel but your engine cant draw in enough air it will start to smoke black.This is unburned fuel. All the mods you read about here pretty much allow more fuel so the engine can make more power. Regarding the poor running, do you buy fuel in Mexico? that I could see being a source of filter plugging and water if its anything like the Pemex we used to get for the gassers. Id try a filter swap and overflow valve since youve done most all other stuff. your SURE the fuel lines are good?
12-17-2005, 11:29 AM
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Went out and started truck 1st try tried what mikmaze suggested and I will see if that could be a solution.
The next will be to just replace those supply lines to make sure I'm not sucking air there.
I always change my oil and filter before I head south and always use the bigger stations where the truckers go to stay away from badly filtered fuel and water. I have never had any problems with diesel fuel down there outside of not being able to get it.
The next will be to just replace those supply lines to make sure I'm not sucking air there.
I always change my oil and filter before I head south and always use the bigger stations where the truckers go to stay away from badly filtered fuel and water. I have never had any problems with diesel fuel down there outside of not being able to get it.
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12-18-2005, 12:22 PM
#8
It is VERY possible the return line from the injectors, is leaking. It is at the back of the head drivers side. This line may not leak fuel out, just air in. It is common.
You are not getting air in the SUPPLY lines.
You are not getting air in the SUPPLY lines.
12-19-2005, 08:34 AM
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NO air J fox! So far I have used the advice of Mikmase and the truck starts every time so far no problem maybe it is just the bleedback as he explained. truck runs perfect.
Hopefully this is the problem.
Thanks
Chris
Hopefully this is the problem.
Thanks
Chris
12-19-2005, 10:11 AM
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With milkmazes reply, It sounds like hes refering to a 24V? If you turn on the key, and just let it sit, no PSI will be building, the engine needs to be turning to build FP, The pump is mechanical and runs off a lobe on the engines camshaft. FWIW, I need to hold the throttle about 1/4 way down to get mine started when its cold out only. My idle is set fine when its warm, but on cold starts its finicky.
12-19-2005, 10:54 AM
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As was said; a 12 valve has no electric lift pump, so it will make no difference how long you sit there. I am with Infidel in thinking overflow valve myself, or fuel lines still bad. I dont really feel like it would be your timing. Id say its due for an overflow valve either way, so id replace that, and go from there. And like the others said. Diesels cant run rich or lean. The less fuel, the less power, the more fuel, the more power. Good luck
Eric
Eric
12-19-2005, 12:53 PM
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Truck did not start right away this morning had to put foot into it alittle. Thinking or replacing the lines all the way back to tank as was done by some others.
I'm in california so it may have been in the high 40's at the lowest temp when I attempted to start.
where is the overflow valve? I just replace the prime pump so it is new that was my first quest as it was bad and getting air in the lines!
CG
I'm in california so it may have been in the high 40's at the lowest temp when I attempted to start.
where is the overflow valve? I just replace the prime pump so it is new that was my first quest as it was bad and getting air in the lines!
CG
12-19-2005, 07:20 PM
#13
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Replacing the OF valve is a five minute one wrench job if you don't drop the sealing washers, stuff a rag under the valve to catch a falling washer. Remove the old valve and put new one in it's place. Occasionally the notch in the manifold you see to the left of the OF valve in the picture needs to be filed or ground a little to allow the old valve to be removed. Don't bend the line to remove the valve, it will make it very difficult to line up again. New style OF valves don't always have the retainer on top that says not to remove, don't worry it's just a design change.
You won't find a better price than here
Precision Diesel Injection and Turbo Inc.
Marty Tompkins
888-734-7349
$35 + $7 shipping and handling.
The object in the lower left corner is the oil fill cap.
You won't find a better price than here
Precision Diesel Injection and Turbo Inc.
Marty Tompkins
888-734-7349
$35 + $7 shipping and handling.
The object in the lower left corner is the oil fill cap.
12-19-2005, 09:38 PM
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While you are in the truck, pull the fuel heater apart and install a new fuel screen. Also, pop the connector to the heater out and fill it with dielectric grease, then plug it back in.
Then regarding the need to step down on the throttle to start a 12 valve, that is almost always an indicator that the timing has slid down below 9 degrees. (Unless your grid heaters are not working.) Generally speaking, unless someone has compensated for a slow idle by setting the idle back up, the truck will also idle below the 750 it should be if the timing has backed down.
In your fuel line quest, be sure you replaced the flexible lines from the top of the fuel tank to the steel lines on the frame. It is also a good idea to check the fuel pick-up hose inside the tank, as it cracks and will allow air to infiltrate when ever the tank is down about a third or more.
Lastly, go get a set of Foster's starter solenoid contacts and replace yours for grins. All the OEM starter contacts eventually burn and will reduce voltage available to the fuel shutoff solenoid. That can make them a real bugger to start, as the fuel solenoid will either not lift or will be real slow to lift.
Then regarding the need to step down on the throttle to start a 12 valve, that is almost always an indicator that the timing has slid down below 9 degrees. (Unless your grid heaters are not working.) Generally speaking, unless someone has compensated for a slow idle by setting the idle back up, the truck will also idle below the 750 it should be if the timing has backed down.
In your fuel line quest, be sure you replaced the flexible lines from the top of the fuel tank to the steel lines on the frame. It is also a good idea to check the fuel pick-up hose inside the tank, as it cracks and will allow air to infiltrate when ever the tank is down about a third or more.
Lastly, go get a set of Foster's starter solenoid contacts and replace yours for grins. All the OEM starter contacts eventually burn and will reduce voltage available to the fuel shutoff solenoid. That can make them a real bugger to start, as the fuel solenoid will either not lift or will be real slow to lift.