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Long start

Wiser

Wiser

NAXJA Forum User
Location
92345
Hi fellow Xjers,

Is it normal for older Xjs 96 and down to have a longer start? I had changed my fuel pump to a brand new Napa pump thinking my check valve was bad originally. I did notice that once I turned off the jeep and go check the Schrader valve I had no fuel squirting out. Is this normal? BTW, the jeep runs fine, no problems. Thanks

1991, 4.0L, AW4 4x4
 
Try turning the ignition on 2-3xs for 3secs each time before you try to crank it over.


Sent from my iPhone using Tapatalk
 
I thought earlier years had an external check valve or at least common to add one outside or the tank.

I'd agree with priming it by turning the ignition on for a few seconds and off again a few times and see if that solves it.
 
Wiser said:
Hi fellow Xjers,

Is it normal for older Xjs 96 and down to have a longer start? I had changed my fuel pump to a brand new Napa pump thinking my check valve was bad originally. I did notice that once I turned off the jeep and go check the Schrader valve I had no fuel squirting out. Is this normal? BTW, the jeep runs fine, no problems. Thanks

1991, 4.0L, AW4 4x4
Click to expand...

No that is not normal, it could be a leaking injector which can wipe out a piston-cylinder fast if not fixed right away!!!! Or it could be the pressure regulator on the fuel rail not holding pressure on a 91. I do not think the 91-95 used a check valve in the fuel pump, but I could be wrong.
 
Thanks for all that replied, I'm going to change out the Fuel Pressure regulator because I did notice a little fuel inside the vaccum line.
 
Ecomike said:
No that is not normal, it could be a leaking injector which can wipe out a piston-cylinder fast if not fixed right away!!!! Or it could be the pressure regulator on the fuel rail not holding pressure on a 91. I do not think the 91-95 used a check valve in the fuel pump, but I could be wrong.
Click to expand...

Could I add an external check valve like the BMW valve? If so does it have to be the BMW valve or can I go with any check valve that would be the same size as my fuel line.
 
Don't add an external check valve--fix/replace the one in the tank if it's not a leaky injector. You could pull the fuel rail off with injectors still clipped to it and connected to harness and do the prime test to verify the injectors aren't leaking. 96 is the first year of the returnless, internally regulated 49psi at all times system. I've never had a problem with the check valve until I swapped in a 97-01 tank with fuel pump(of course).


Sent from my iPhone using Tapatalk
 
gradon said:
Don't add an external check valve--fix/replace the one in the tank if it's not a leaky injector. You could pull the fuel rail off with injectors still clipped to it and connected to harness and do the prime test to verify the injectors aren't leaking. 96 is the first year of the returnless, internally regulated 49psi at all times system. I've never had a problem with the check valve until I swapped in a 97-01 tank with fuel pump(of course).


Sent from my iPhone using Tapatalk
Click to expand...

I had recently pulled all the injectors and fuel rail to clean them. I did not notice them leaking nor weak when i shot injector cleaner through them.
 
Wiser said:
I had recently pulled all the injectors and fuel rail to clean them. I did not notice them leaking nor weak when i shot injector cleaner through them.
Click to expand...

And your point is?
 
Ecomike said:
And your point is?
Click to expand...

Point is.. Wouldn't they leak if I were to run a pressurized cleaner through them? Therefore, it would be diagnosed as a leaky injector possibly causing the complete loss of pressure in the fuel rail?
 
MACH90XJ said:
Sometimes the old starter just get weaker. My newer Bosch starter cranks way faster than what died a few years back.
Click to expand...

I had replaced my starter about 4 weeks ago with a Bosch unit. Seems to still be cranking strong
 
Best if you could borrow a fuel pressure regulator and check it doesn't bleed pressure down.

I would also consider a CKP sensor problem.
 
Patrick S. said:
Best if you could borrow a fuel pressure regulator and check it doesn't bleed pressure down.

I would also consider a CKP sensor problem.
Click to expand...

I know of someone who has one, I'll see what I can come up with
 
Wiser said:
Point is.. Wouldn't they leak if I were to run a pressurized cleaner through them? Therefore, it would be diagnosed as a leaky injector possibly causing the complete loss of pressure in the fuel rail?
Click to expand...

The process of opening the system and cleaning can introduce or loosen crap that comes loose later after reassembly and sticks an injector open.

A leak down test on the fuel rail (no fuel or pressure at the rail test point) confirms a leak somewhere. The only question is where. If it is an injector and you drive it, it can cause permanent damage to the piston and cylinder very quickly while running the engine. I think unburnt fuel is why gas engines die so much faster than diesel engines, diesel fuel is a lubricant, not a solvent to a great extent. One of our members killed his engine in 1-2 hours of driving as I recall with one cylinder not firing or a leaking injector, I forget which.
 
Unburnt fuel can make its way pass the rings and make its way to the oil. Fuel diluted oil will cause bearing damage if run to long. No bueno .

After fixing your no fuel pressure issue, I would recommend changing your oil to insure healthy oil is reaching your bearings.
 
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