How do I know if my fuel pump is bad?
#1
How do I know if my fuel pump is bad?
Sorry for stupid question..
I have got one -99 XJ8 Vandenplas, with no start..
I checked the spark, and it gets good power/sparks
But I checked the inertia valve, NO FUEL PRESSURE
New battery
Checking the trunk fuses, fuel pump 7 gets power while cranking, not the 15 (but that one is for the Supercharged, right?)
Cannot hear and "clicking" on the relay..
Still no fuel up in the engine room, and no noise from any pump..
What do I do next?
Thank You
Sorry if this is a old thread, but I could not find anything directly like mine..
I found how to change pump and so, but I want to know if it is bad before changing
Glenn
I have got one -99 XJ8 Vandenplas, with no start..
I checked the spark, and it gets good power/sparks
But I checked the inertia valve, NO FUEL PRESSURE
New battery
Checking the trunk fuses, fuel pump 7 gets power while cranking, not the 15 (but that one is for the Supercharged, right?)
Cannot hear and "clicking" on the relay..
Still no fuel up in the engine room, and no noise from any pump..
What do I do next?
Thank You
Sorry if this is a old thread, but I could not find anything directly like mine..
I found how to change pump and so, but I want to know if it is bad before changing
Glenn
#2
The # 16 / 10 amp LH heelboard fuse closes the pump power relay
In order for the fuse to have power the Ignition Positive Relay must close
It is located in the corner of the fuse holder that holds the other 18 fuse and can be swapped for testing purposes with the RH heelboard fuse holder relay
In order for the fuse to have power the Ignition Positive Relay must close
It is located in the corner of the fuse holder that holds the other 18 fuse and can be swapped for testing purposes with the RH heelboard fuse holder relay
Last edited by Lady Penelope; 01-07-2019 at 03:49 AM.
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#3
Editing with some additional information left out earlier , I had a appointment
If you put your finger on the # 1 relay it will click on for 4 seconds then click back off as you rotate the key to the on position before the start position
The relay will click back on with a 3rd click as the engine ECU sees engine rotation and will stay on for the duration of the drive
This is a safety design
There is also a safety design feature of a crash switch that when tripped for whatever reason prevents the pump from running
You would have to put your finger on the specific relay as there are others in the area that will click in the starting sequence
Battery fully charged state of 12.75 volts
As the battery drains down there is not enough voltage to run the ECU properly , this prevent the fuel injectors from delivering fuel to the cylinders
A condition called bore wash can accure if unburned fuel washes the very thin oil film off the cylinder walls . This prevents the cylinders from having enough compression for a sustained engine light off
This can be fixed by a sequence of starter rotation with the gas pedal to the floor . By design this will cut off the fuel being delivered to the cylinders and on the underside of the pistons some new oil will recoat the cylinder walls for better compression later when you relax the gas pedal
Nickasol condition for the AJ26 engine for the 98 - 99 year production , Need to determain if you have the swapped out later AJ27 engine before going into detail
Editing complete and running errands so someone else can get you going
If you put your finger on the # 1 relay it will click on for 4 seconds then click back off as you rotate the key to the on position before the start position
The relay will click back on with a 3rd click as the engine ECU sees engine rotation and will stay on for the duration of the drive
This is a safety design
There is also a safety design feature of a crash switch that when tripped for whatever reason prevents the pump from running
You would have to put your finger on the specific relay as there are others in the area that will click in the starting sequence
Battery fully charged state of 12.75 volts
As the battery drains down there is not enough voltage to run the ECU properly , this prevent the fuel injectors from delivering fuel to the cylinders
A condition called bore wash can accure if unburned fuel washes the very thin oil film off the cylinder walls . This prevents the cylinders from having enough compression for a sustained engine light off
This can be fixed by a sequence of starter rotation with the gas pedal to the floor . By design this will cut off the fuel being delivered to the cylinders and on the underside of the pistons some new oil will recoat the cylinder walls for better compression later when you relax the gas pedal
Nickasol condition for the AJ26 engine for the 98 - 99 year production , Need to determain if you have the swapped out later AJ27 engine before going into detail
Editing complete and running errands so someone else can get you going
Last edited by Lady Penelope; 01-07-2019 at 12:42 PM.
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theswede (01-07-2019)
#4
Whatever I did or measured, no start of pump..
So I started to take the tank out, for checking the pump, ..aaand it smells lie kerosene! Tank not out yet, but already I guessing this Jag has been standing for a longer time..
So I guess the pump is shoot, or so..
Lets see what's hiding in there..
I had to gave upon my driveshaft was disconnected, the fuel line tool I had, was no way to get it off, I making me a tool tomorrow or some other day..
Everything in the trunk is done, just the making of a tool left to do..
I saw somewhere here a homemade tool of some pipe for toilets that worked!
But I thinking about to buy some water lines, or some other plastic pipes, to make it from..
So I started to take the tank out, for checking the pump, ..aaand it smells lie kerosene! Tank not out yet, but already I guessing this Jag has been standing for a longer time..
So I guess the pump is shoot, or so..
Lets see what's hiding in there..
I had to gave upon my driveshaft was disconnected, the fuel line tool I had, was no way to get it off, I making me a tool tomorrow or some other day..
Everything in the trunk is done, just the making of a tool left to do..
I saw somewhere here a homemade tool of some pipe for toilets that worked!
But I thinking about to buy some water lines, or some other plastic pipes, to make it from..
#7
I think I know the reason..
I think I know the reason now!! Why I didn't get and fuel, and why I could not get the pump to start...
I smelled like kerosene and all grommets and plastics was eaten up totally
Ethanol!!
Why in the *&^% do the government force Us to use this bi-product that just damages vehicles etc..!????
Oh well, they earn money on a product they have to pay to get rid off otherwise...
The car had been parked for some years, but this is ridiculous
I smelled like kerosene and all grommets and plastics was eaten up totally
Ethanol!!
Why in the *&^% do the government force Us to use this bi-product that just damages vehicles etc..!????
Oh well, they earn money on a product they have to pay to get rid off otherwise...
The car had been parked for some years, but this is ridiculous
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#8
#10
#11
I ordered one BOSCH fuel pump, that I hope is an OEM pump, or OEM alike.. I just seems to trust BOSCH more than some others out there, hope that I am not wrong
I might/should bought to high pressure one from the Super charged Jag instead.. :/
Ok, so I and scrolling around to try to buy the items in the tank, with no really success..
I what to get all the parts for the inside the tank, such as clamps, hoses, the little filter for the return, the return hose, grommets and the fuel line attachments in the bottom for the feeding/return line etc...
This tank was a pian in the butt to get out, in the garage floor and on jack stands..
But it came out, and now I want to make it RIGHT!
Change everything so I NEVER need to get it out once more!
I might/should bought to high pressure one from the Super charged Jag instead.. :/
Ok, so I and scrolling around to try to buy the items in the tank, with no really success..
I what to get all the parts for the inside the tank, such as clamps, hoses, the little filter for the return, the return hose, grommets and the fuel line attachments in the bottom for the feeding/return line etc...
This tank was a pian in the butt to get out, in the garage floor and on jack stands..
But it came out, and now I want to make it RIGHT!
Change everything so I NEVER need to get it out once more!
#15
Back valve and discontinued parts
Still I have not found what I needed..
I was even at the Jaguar dealer but they said that the "in tank" hoses is discontinued, and they did not know about that "back valve/filter" I got in the incoming fuel line/return.. And that hose was really some kind of special, one size on the incoming side and a smaller on the other, and that is where I got that "back valve"
That hose "is no more"..!
So I have to fab something..
But hey, what do I do about "My back valve"?
Skip it?
It definitely looks like original, no "extra fix thingy".. I don't believe anyone has been in there since the car was assembled at Jaguar.. :/
So I can get hold of hose NO: 6 but not the "other" with the "back Valve"
Well, I might just buy 2 No 6 and "fix" that other side somehow
My plan is to get all stuff in tank, NEW! And as OEM, as possible or better
I was even at the Jaguar dealer but they said that the "in tank" hoses is discontinued, and they did not know about that "back valve/filter" I got in the incoming fuel line/return.. And that hose was really some kind of special, one size on the incoming side and a smaller on the other, and that is where I got that "back valve"
That hose "is no more"..!
So I have to fab something..
But hey, what do I do about "My back valve"?
Skip it?
It definitely looks like original, no "extra fix thingy".. I don't believe anyone has been in there since the car was assembled at Jaguar.. :/
So I can get hold of hose NO: 6 but not the "other" with the "back Valve"
Well, I might just buy 2 No 6 and "fix" that other side somehow
My plan is to get all stuff in tank, NEW! And as OEM, as possible or better
#17
#18
So now I searching for the Mounting rubbers for the fuel pump on my Jaguar XJ8 1999..I need the NND6025BA and the NND6025AA, Where can I find them or replacements??
The following 4 users liked this post by M. Stojanovic:
#20
Well, I finally come to shoot, and reassembled my fuel tank with an new BOSCH pump, all new hardware and new hoses etc inside the tank, all new stuff
And new quick connectors for the tank connectors/fuellines..
New K&N fuel filter..( and blow the old gunk out from the fuel lines, was old gasoline that smelled like turpentine and looked like old oil "goe"
The car had been parked for like 8 years?!
Got the tank back in the car, filled some fuel, and primed the lines
And to a surprise, she spun up! First time for me.. well spun and spun, kinda sputtered and so..
But at least she kinda run!
So how do I clean my injectors?
Any ideas/suggestions?
And new quick connectors for the tank connectors/fuellines..
New K&N fuel filter..( and blow the old gunk out from the fuel lines, was old gasoline that smelled like turpentine and looked like old oil "goe"
The car had been parked for like 8 years?!
Got the tank back in the car, filled some fuel, and primed the lines
And to a surprise, she spun up! First time for me.. well spun and spun, kinda sputtered and so..
But at least she kinda run!
So how do I clean my injectors?
Any ideas/suggestions?