Can low fuel pressure cause no spark...newbie question
#1
Can low fuel pressure cause no spark...newbie question
I guess you ultimately get what you pay for, but I never seem to learn that lesson in all my years of vehicle ownership.
I recently bought a 1998 Dodge 2500HD from the wife of a deceased owner in my town. The truck had extremely low mileage (34700) and the service records showed that it had been well cared for during her husband's ownership. Unfortunately, the truck had be parked and sat unused for the last five years. Initial inspection showed that it needed a starter and had a leaking fuel rail. After they were replaced, the truck did start up and moved (we immediately blew a brake line and the transmission cooling line). The price was right, so we decided to take on the truck as a project.
After getting it towed to my house, the truck did start again, although hard and after much cranking. Since the fuel filler neck was rotted away, we could not immediately put fresh gas into the truck and it (apparently..we assume) ran out of gas and died during one of our test runnings. We were able to pump some new gas into the tank and when we tried to start it again, all it would do is crank and crank, but not fire up.
We checked and found that we were not getting any spark. We replaced the coil, but still no spark. I have since done the following....
After each of these procedures, we have tried to start the engine, get lots of cranking, but no spark. We have noticed that there are now leaks in the other fuel rail and in the fuel delivery line, as we get abundant amounts of gas during cranking. (No, I'm not positive that it lasts more than three seconds. I will check that when I pull the fuel delivery line.)
So all of this background is to ask the question...
If I am not getting sufficient fuel pressure, is the ECM seeing this and not providing spark signal? I have new/used fuel rails, rebuilt injectors and a new fuel line ready to install.
I don't see how running it out of gas could cause the truck to not have spark. It could be a coincidence. It could be that the truck never actually ran out of gas and just sounded like that as a sensor died. In any case, I'm getting mighty frustrated and want to get this issue solved, so I can move on to getting the other systems (brakes, cooling, tranny, etc.) serviced and the truck back on the road.
Any advise or direction would be greatly appreciated.
Many Thanks from a newbie
KURT
I recently bought a 1998 Dodge 2500HD from the wife of a deceased owner in my town. The truck had extremely low mileage (34700) and the service records showed that it had been well cared for during her husband's ownership. Unfortunately, the truck had be parked and sat unused for the last five years. Initial inspection showed that it needed a starter and had a leaking fuel rail. After they were replaced, the truck did start up and moved (we immediately blew a brake line and the transmission cooling line). The price was right, so we decided to take on the truck as a project.
After getting it towed to my house, the truck did start again, although hard and after much cranking. Since the fuel filler neck was rotted away, we could not immediately put fresh gas into the truck and it (apparently..we assume) ran out of gas and died during one of our test runnings. We were able to pump some new gas into the tank and when we tried to start it again, all it would do is crank and crank, but not fire up.
We checked and found that we were not getting any spark. We replaced the coil, but still no spark. I have since done the following....
- replaced the coil
- replaced the cam sensor in the distributor
After each of these procedures, we have tried to start the engine, get lots of cranking, but no spark. We have noticed that there are now leaks in the other fuel rail and in the fuel delivery line, as we get abundant amounts of gas during cranking. (No, I'm not positive that it lasts more than three seconds. I will check that when I pull the fuel delivery line.)
So all of this background is to ask the question...
If I am not getting sufficient fuel pressure, is the ECM seeing this and not providing spark signal? I have new/used fuel rails, rebuilt injectors and a new fuel line ready to install.
I don't see how running it out of gas could cause the truck to not have spark. It could be a coincidence. It could be that the truck never actually ran out of gas and just sounded like that as a sensor died. In any case, I'm getting mighty frustrated and want to get this issue solved, so I can move on to getting the other systems (brakes, cooling, tranny, etc.) serviced and the truck back on the road.
Any advise or direction would be greatly appreciated.
Many Thanks from a newbie
KURT
#2
Computer doesn't have a clue what fuel pressure is, so, no. No connection between fuel pressure and lack of spark.
The sensor in the distributor is the Cam Position sensor. It has nothing to do with ignition. It only clues the PCM in to which injector it should be firing.
Check and see if you are getting power TO the coil. You will only see power for a few seconds after turn the key on, so, two people to test is pretty much a requirement. If you are getting power, next likely culprit is the crank sensor. (sorry.....) Yeah, it is in a rather screwy location, and not exactly easy to get to. I pulled the air box off the throttle body, tossed a rag over the TB, and then put a board over the motor that I could lay on, to pull the bolts for the crank sensor. They should have an allen socket in the bolt head as well, if that makes things any easier for you.
This is an occasion where the arm with three elbows comes in REAL handy.....
Welcome to DF!
The sensor in the distributor is the Cam Position sensor. It has nothing to do with ignition. It only clues the PCM in to which injector it should be firing.
Check and see if you are getting power TO the coil. You will only see power for a few seconds after turn the key on, so, two people to test is pretty much a requirement. If you are getting power, next likely culprit is the crank sensor. (sorry.....) Yeah, it is in a rather screwy location, and not exactly easy to get to. I pulled the air box off the throttle body, tossed a rag over the TB, and then put a board over the motor that I could lay on, to pull the bolts for the crank sensor. They should have an allen socket in the bolt head as well, if that makes things any easier for you.
This is an occasion where the arm with three elbows comes in REAL handy.....
Welcome to DF!
#3
Thanks..I guess...LOL
Thanks for the response HeyYou...although your reply wasn't exactly what I wanted to hear. I have seen the various posts on how to change the crank sensor and none of them have a magical solution.
Why in the world would Chrysler make such an impossible design? How did Dodge Techs do it I wonder? Working on the distributor is bad enough, but this puppy is next to impossible to access. To make matters worse, age has made to allen bolts pretty corroded and not easy to slot in a wrench even if I could get to it.
I did find a great write up on how to test the sensor while it's in place. Also a two person process, but I guess I'll start there. All I need access to is the back of the connecting plug and I can back-probe it while someone turns the engine over by hand.
I also guess that the ECM could be bad, but I don't think so. Ah, the joys of old truck ownership. Next time I'm just gonna bite the bullet and buy meself a new diesel rig. I just hate to spend that type of dough on what is essentially a "toy" for me and my old car hobby.
Thanks again for the advise.
KURT (crying)
Why in the world would Chrysler make such an impossible design? How did Dodge Techs do it I wonder? Working on the distributor is bad enough, but this puppy is next to impossible to access. To make matters worse, age has made to allen bolts pretty corroded and not easy to slot in a wrench even if I could get to it.
I did find a great write up on how to test the sensor while it's in place. Also a two person process, but I guess I'll start there. All I need access to is the back of the connecting plug and I can back-probe it while someone turns the engine over by hand.
I also guess that the ECM could be bad, but I don't think so. Ah, the joys of old truck ownership. Next time I'm just gonna bite the bullet and buy meself a new diesel rig. I just hate to spend that type of dough on what is essentially a "toy" for me and my old car hobby.
Thanks again for the advise.
KURT (crying)
#4
I would offer a shoulder to cry on (being familiar with trying to get the crank sensor out) but, you are a bit of a distance away.
Dodge probably had some 300 dollar special tool that make it easy.
If you have allen sockets.... and a couple extensions, that helps.... but, it ain't ever gonna be considered 'easy'.
Dodge probably had some 300 dollar special tool that make it easy.
If you have allen sockets.... and a couple extensions, that helps.... but, it ain't ever gonna be considered 'easy'.
#5
#6
I've found on my 98 1500, that if i get a throwable life vest type of thing like this: http://watercraft.ohiodnr.gov/portal...-throwable.png
and sit on the outside of the engine compartment, i can get my feet set up inside the compartment and it's a bit easier to work with.
and sit on the outside of the engine compartment, i can get my feet set up inside the compartment and it's a bit easier to work with.
#7
Thanks for the sympathy, support and suggestions. I've already cut a plywood sheet to fit in my engine bay for me to lie down on and work. I'm still black and blue from all the gymnastics needed to access the distributor and the crank sensor. While I can see the crank sensor from underneath, I have no idea how you guys accessed it to remove it. In my 2500, the manifold downpipe is in the way...and I'm NOT taking the manifold off!
I am going to try and get some wobbley-tipped allen sockets and see if that helps. One of my biggest problems is that the corrosion on the allen screws is pretty bad and I'm having a tough time slotting in anything. Just gotta keep trying I guess. I'm still going to test the sensor before killing myself to take it out.
I will keep you informed on how things go.
Thanks again,
KURT
I am going to try and get some wobbley-tipped allen sockets and see if that helps. One of my biggest problems is that the corrosion on the allen screws is pretty bad and I'm having a tough time slotting in anything. Just gotta keep trying I guess. I'm still going to test the sensor before killing myself to take it out.
I will keep you informed on how things go.
Thanks again,
KURT
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#8
#9
The secret sauce is KROIL
A car restorer friend on mine put me on to this stuff a while back and I've used it on all my projects since. It's available thru Amazon and comes in various sizes and forms. I use both the aerosol and the 1 gallon bulk in an oiler. It also comes with silicon added. That product is called SILKROIL. I have not used that version.
The stuff is absolutely amazing! It dissolves rust, frees stuck bolts/screws and makes the impossible, possible. The trick is to be patient. Don't expect to spray it on and then wrench the bolt off. That's not how to do it.
First wack the item(s) you want to free with a hammer,etc. then spray on the KROIL. Hit it again and give it another shot. Now go work on another area of your project. The longer you wait, the better the results. Go back and hit it again and then try and remove the stuck bolt, nut, screw. Be patient and don't try to muscle it, you'll just snap the head off. If its really stuck, continue with the hitting and applying more fluid. It will come loose.
I have used this product and method on several of my recent projects and have never not been able to get out even the most hardcore cases. I'm sure I'll run into something that this stuff won't touch, but I haven't so far.
Good luck,
KURT