DI Hard restart when hot...

[voyageur]

Sort of a a new phenomenon, which I don't like. Made a trip (45 min) 65 mph stopped for lunch. Forty five minutes later, returned to Disco and attempted to start. Turned over normally, started up normally (30seconds) started to shudder and then died. Had to restart about five times. Each time I had to repeatedly tap the accelerator and then run at high idle, until the engine smoothed out and ran normally. Once underway, return trip was uneventful. This phenomenon has recurred on three other trips - same symptoms and cure.

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In the old days I would have said it was "vapor-locked."

Relevant data:

Air Temp 85 degrees.
A/C on.
Electric aux cooling fan running normal.
Temperature gauge normal.
Sahara - ample air flow.
Gas tank half full.

Any ideas. Plugs? Tune-up? ??????

Thanks for any suggestions...

 

[ntsqd]

Last fuel filter replacement was when?

 

[voyageur]

Theres a fuel filter???

Hmmm... Sure is terrible to be publicly revealed as a dumb :shakin:.

I have owned the car for three years so, it has been at least that long. Where is the filter? I know I can look in my manual (if I had a manual).

 

[voyageur]

Is this the right procedure?

1. Put the transmission into park, and turn the vehicle off.
2. Disconnect the blue fuel pump relay in the passenger side foot well side panel.
3. Start the vehicle, and when the fuel system depressurizes, the engine will stall. Now turn the vehicle off.
4. Disconnect the Battery
5. Remove the right rear tire, using proper wheel removal procedures outlined in your Land Rover Discovery's owners manual.
6. Using 2 wrenches disconnect the fuel filter. For this step make sure to have towels or a cardboard box of newspaper or something to catch spilled fuel (This is normal and unavoidable).
7. After removing the old fuel filter, replace with a new fuel filter, making sure the flow path for the filter is correct and tighten the connections at both ends of the fuel filter.
8. Wash hands
9. Reconnect the Fuel Pump Relay
10. Reconnect the Battery
11. Start the Vehicle, and check for leaks at the fuel filter.
12. If all is well refit the wheel, lower the rear end, and your good to go!

 

[bobDog]

XJs get this a lot.....they get #3 injector heat soaked while sitting and it causes a vapor lock in that injector. Never heard of it in any other vehicle except in XJ Cherokees we heat shield the #3 withe foil backed insulation. Usually only happens during hot weather or did you lose a metal shield.

 

[voyageur]

Thanks BobDog...

Good point. I will check shields and spark plug wires for clearance...
Thanks...

 

[evilfij]

On a land rover this is cause most likely by a bad ignition module or a leaking injector.

Ron

 

[Antichrist]

But after 3 years it should have a new fuel filter installed anyway.
I never bother bleeding the fuel system, I just put a rag under the fittings and disconnect them. Of course, bleeding it doesn't hurt.

 

[voyageur]

Thanks again...

Tom I need to do the same thing on Lucy's D II (1999), Is the fuel filter in the same place? Same part number?

Happy "Mutha's Day" Everybody...

 

[evilfij]

But after 3 years it should have a new fuel filter installed anyway.
I never bother bleeding the fuel system, I just put a rag under the fittings and disconnect them. Of course, bleeding it doesn't hurt.

Agreed, but unlikely to be the issue unless you are running dirty gas. Fuel filters usually show up as down on power under heavy load.

 

[Antichrist]

Tom I need to do the same thing on Lucy's D II (1999), Is the fuel filter in the same place? Same part number?

No, DII's don't have an inline filter.

 

[muskyman]

Ron is on the money...this is classic D1 injector leak down.

 

[voyageur]

Regarding possible injector "Bleed Down"...

In the past, I have used some carefully sprayed bursts of brake cleaner, to attempt to track down vacuum leaks. If the leak allowed the brake cleaner to be sucked into the fuel system, the engine would speed up slightly for a few seconds and you could find the offending hose or fitting.

If I sprayed it near each injector would it similarly be sucked into the leaky injector, causing the engine to increase RPM's for a few seconds?

OR, is there a check valve that is designed to prevent the injectors from losing pressure each time the engine is shut down?

 

[muskyman]

In the past, I have used some carefully sprayed bursts of brake cleaner, to attempt to track down vacuum leaks. If the leak allowed the brake cleaner to be sucked into the fuel system, the engine would speed up slightly for a few seconds and you could find the offending hose or fitting.

If I sprayed it near each injector would it similarly be sucked into the leaky injector, causing the engine to increase RPM's for a few seconds?

OR, is there a check valve that is designed to prevent the injectors from losing pressure each time the engine is shut down?

The injector has a disc that the actuator plunger pushes down on inside the injector that deposits build up on and prevent it from properly closing. this causes fuel from the fuel rail to pour into the intake manifold after shut down and this creates a overly rich condition when you try to start the engine. stepping on the throttle opens the throttle plate and allows the engine more air to lean it out and help it start. Then it will run rough until it burns off the extra fuel.

The real problem is that is ruins the oil and reduces its lubricity so leaving the condition unattended too will cause increased engine wear pollute the cats with fuel making them run hot and burn up.

BG44K, chevron techron, and lucas injector cleaner all do a good job on mild cases but it is really best to either replace the injectors or have them serviced by a injector service company.