Hi my forum’s friends,
On my previous post I was having problems with my car running rough, now I have a new problem, after I finally got the j40 running at a 97% good, the engine stopped running. I was showing the engine to my uncle, after 10 minutes the engine stopped running with no signal, try to crank the engine few times and nothing, waited 10 minutes and tried to crank and nothing. I pulled a spark plug cable and there was no spark going to the spark plug. Will the coil make the engine stop running with no signal. When I put the key on on position the check engine light is not on.
I will appreciate any advice on this problem I’m encounter now.

 

Does the rev counter show anything when you crank the engine? If not. that often points to a bad connection at the harness or failing crank position sensor. If the rev counter does show movement, next thing to check or replace would be the rotor inside the distributor cap. They are known to fail.

 

Hi Lawrence,
Something is not right with the car, I called my uncle and explained what to look for when he tried to startup the car, when I ask were the RPM was showing and he told me that the engine was running. Well it only lasted around one minute before it went off, try to start the engine again a couple of times and nothing happens, I guess I have to check if the pump is working.
Thanks

 

If the battery voltage sags much below 11 volts while cranking, the ECM will not trigger the ignition to fire.

A quick check of the fuel pump is to turn the key to position 2 (Ignition ON) but do not start the engine. You should hear the fuel pump run for a few seconds to prime the fuel system. The pump is in the fuel tank behind the rear seat, so listen carefully to that area. You can force the fuel pump to run by bending a large paperclip into a U shape and using it to jump terminals 30 and 87 in the fuel pump relay socket.

Could the fuel be contaminated with water? This can cause both rough running and a no-start condition. Is the drain hole in the rubber gaiter around the fuel filler neck clogged with seeds or leaves? If so, when it rains or you go through a car wash, water can pool high enough to seep past the fuel cap and down into the fuel tank. Water is denser than gasoline/petrol, so it sinks to the bottom of the tank where it is inhaled by the fuel pump.

Cheers,

Don

 

Hi Don,
I have changed some parts including the fuel filter, also has cleaned the maff sensor, throttle body and idle valve. Three weeks before it quit running, the fuel pump was loud and the hose going to the fuel filter was vibrating strong. Week before it stopped running, the fuel pump was not loud and the fuel hose going to the filter was not vibrating like before. I have to check if there is fuel coming out of the hose connection before the fuel pressure regulator. Were is the location of the relay.
Thanks for the info

 

Hi to all my forum friends,
I have checked the fuel pump and it’s working, turn the car on with a hesitation on the engine because the rpm was dropping down to 400 rpm’s. If I raise it to 800 rpm’s it’s smooth, after a couple of minutes I can let the gas down and it will drop to 650 rpm’s and stay running smooth, I can raise the rpm to 1500 and let the gas off and it will drop to 500 - 600 and stay running fine. I had the car running for around 15 minutes and the engine started to hesitate and was trying to go off at the same time I was pushing the gas pedal trying to keep it running, ( trying to keep up with the rpm’s 1700 - 2500 but it looks like it was starving for fuel ). The engine started sputtering and stopped running, I was not able to get it running again. It seems that there is a problem when the engine is getting hotter.

I will like to get some feedback on what can be causing this problem.
Thanks

 

Hi Eddig01,

As I asked in Post #4, is it possible the fuel is contaminated with water? This is quite common on the Jaguars with the vertical fuel filler necks. You could try adding two bottles of Heet fuel system water remover to your fuel tank and agitating by bouncing the rear bumper up and down to help mix the Heet with any water that may be in the bottom of your fuel tank. If you can then get the engine to start and run for awhile, it may smooth out as the water works through.

You said before that the Check Engine Light was not on. Is it on now?

Cheers,

Don

 

Hi Don,
I’ve has gone through two bottles of Seafoam fuel treatment, it removed water, cleaned injectors, stabilize fuel, cleaned deposits and lube upper cylinders. I also use the seafoam throttle body cleaner. The problem is when engine warm up, it just quit running and won’t start no matter what I do.
Thanks for responding to this thread.

 

Does the rev counter/tach needle move when cranking?

 

Have you changed the coolant sensor? A failing one can really mess up the fuel map.

 

yes first don’t move, after 3 seconds it move between 1000 - 1700 RPM every time I try to crank the engine.
thanks for asking

 

No I have not change it, I noticed that when I disconnected the plug, the air pump clutch engage and stay running unless I turn the engine on, if I disconnect it wild the engine runs it will make the clutch turn on. Is that a safety feature so the engine won’t overheat or that’s to disperse more air to the air filter and intake manifold.

Please excuse me if I sound dumb, but I don’t know much about mechanics.
Thanks for your input on this issue.

 

The air pump usually only operates for a short time when the engine is cold. I wouldn't concern yourself with it. The coolant temp sensor is a fairly dominant component of the air/fuel mixture and not a very expensive part if purchased aftermarket.
e.g. rockauto:
https://www.rockauto.com/en/catalog/...+/+sensor,4748

 

Hi to my forums friends,
So I change both sensors on top of the thermostat, car ran for 8 minutes and engine shut off, tried to turn the engine on and it almost started, try again and it started with a little vibration but it stabilized with in seconds, the rpm’s were at 700, had the car on running around 35 minutes on idle, at times increasing the rpm’s to 1200 and letting it off the gas pedal to see what it would do. The rpm’s stayed around 700, drove it around the block few times and it responded to the acceleration on the road. There still a little miss on the engine and you can hear the miss in the rear mufflers. I had no codes before I started the engine for the first time, after that it gave me code ff 26 and ff 16. I’m not sure if the ff16 is because I change the thermostat sensor. On the ff26 I’m not sure if there is a leak, unless it’s under the intake manifold. I noticed that when I rub it up I hear an air pressure noise on the manifold top of the throttle body, I’m guessing that’s normal. If there is a problem with the mafs sensor, will it show code ff26. A least I was able to have the xj40 running, I’m thinking of getting a new air temperature sensor.

I will appreciate any comments on this two codes ff26 and ff16.

 

FF26 has a few possibles but it usually means you have a vacuum leak in the intake. That would also cause smooth running issues.

 

Hi Lawrence, thanks for responding . I will check all of the vacuums hoses again and will spray the manifold with carburetor fluid. What I found strange is that the engine can be running on idle for 8 - 10 minutes and suddenly the engine shuts off. This was before I replaced the thermostat sensors. I need to clear the codes and see if they show up again.

 

Hi forums friends,
the symptoms still there, the codes came back and the car keeps shutting off after 8-10 minutes. Yesterday had the engine running and it was shutting off every 10 minutes ( 3 times). It crank up right after but it had that up a down RPM, I don’t know what else to do. It seems that is when the engine warm up.