No throttle response

[kamprat]

I have a Ford Transit MK5 camper with the 2,5D 76 Hp engine. I am experiencing one strange problem.
Every time I have driven it a bit, say 1 hour, so the engine is warmed up, and then stop for say 10 minutes, and then start it again. It then starts fine and runs nicely on idle (like always). But there is no response on the throttle pedal. I mean absolutely zero response. I then need to keep it running on idle for 5-10 minutes, and after that it slowly starts to respond to my movements of the throttle pedal. After that it works fine (but still a bit slow on the throttle response for another few minutes), and I can drive off.

What could be the cause of this?

[dumper]

I had a similar problem on my my 3 it had the fuel filter that had a wire ring with a wingnut to clamp the filter in the head I hadn’t pushed the filter tight enough into the filter head so it was able to suck in air in the system it would drive 70 miles no problem but then would struggle to start and rev cleanly.
Had similar problem on my mk5 had to do the injector leak off mod from new the return from the injectors goes back to the tank from number 4 injector what you have to do remove the blank from number 1 injector and fit it on to number 4 injector and get some more proper injector rubber leak off pipe and extend it to number 1 if it has not been done yet already

[Peterr]

If you have the Lucas pump, I had a similar problem. The accelerator sensor under the foot pedal was loose. So pressing the pedal gave no response. Engine runs. I was able to wiggle it back into place so I could get home. Repaired broken plastic with epoxy. Crap stuff.

[kamprat]

I had a similar problem on my my 3 it had the fuel filter that had a wire ring with a wingnut to clamp the filter in the head I hadn’t pushed the filter tight enough into the filter head so it was able to suck in air in the system it would drive 70 miles no problem but then would struggle to start and rev cleanly.
Had similar problem on my mk5 had to do the injector leak off mod from new the return from the injectors goes back to the tank from number 4 injector what you have to do remove the blank from number 1 injector and fit it on to number 4 injector and get some more proper injector rubber leak off pipe and extend it to number 1 if it has not been done yet already

Thanks! I will have a look at the air filter and I will do the leak off mod. Found a video if anyone else is interested: https://youtu.be/M8wIqs14tLU

[kamprat]

If you have the Lucas pump, I had a similar problem. The accelerator sensor under the foot pedal was loose. So pressing the pedal gave no response. Engine runs. I was able to wiggle it back into place so I could get home. Repaired broken plastic with epoxy. Crap stuff.

How do I check if i have the Lucas pump?

I have thought about the accelerator sensor, but my problems occur ONLY and EVERY TIME when I try to rev the engine after it has been first heated up properly, and then it has been off for 5-10 minutes. There is never an issue revving after I do a cold start. I have a feeling it is some sort of overheating issue, that when I stop the car both the cooling fan and the engine cooling fluid pump stops, so it temporarily get alot hotter, causing something to jam somehow.... But that just a guess from a complete amateur

[Altransit]

How do I check if i have the Lucas pump?

A Mk5 with no turbo is almost certainly a Bosch pump, (unless it's been messed with!) The turbocharged version had a lucas electronic pump.

[dumper]

I had a similar problem on my my 3 it had the fuel filter that had a wire ring with a wingnut to clamp the filter in the head I hadn’t pushed the filter tight enough into the filter head so it was able to suck in air in the system it would drive 70 miles no problem but then would struggle to start and rev cleanly.
Had similar problem on my mk5 had to do the injector leak off mod from new the return from the injectors goes back to the tank from number 4 injector what you have to do remove the blank from number 1 injector and fit it on to number 4 injector and get some more proper injector rubber leak off pipe and extend it to number 1 if it has not been done yet already

Thanks! I will have a look at the air filter and I will do the leak off mod. Found a video if anyone else is interested: https://youtu.be/M8wIqs14tLU

Not the air filler the fuel filter that was sucking in air

[cherniy_chack]

Many years ago, I was given a Bosch fuel pump, which I installed on my engine. The engine started without a problem, but wouldn't rev up.
I removed it and took it in for repairs. I explained the symptoms to the mechanic, and he immediately identified the cause.
The booster pump blades were stuck in the fuel pump housing.
After the repair, the pump operates normally.
Bosch fuel pumps operate based on the booster pump pressure moving the timer piston and advancing the fuel injection angle. When the accelerator is released, the pressure drops, and the timer returns to its original position under the action of the timer return spring. When the timer piston and piston sleeve wear, leaks in the gap increase and the timer stops moving under the pressure of the booster pump, which prevents the engine from accelerating. If problems with accelerating begin after the engine, fuel pump, and fuel in the tank have warmed up, and especially in the summer, then wear of the timer piston and sleeve may be the cause.
The pressure regulator valve in the pump body may be worn or stuck.
I don't believe the pump blades are sticking.
In any case, the pump should be examined by a specialist.
It's difficult to give accurate advice over the internet, although sometimes it can be done.

[Peterr]

This may be my problem too. Just fitted a …145 Bosch pump. Second pump I’ve tried without success. Engine wouldn’t start until I turned the fuel screw in a lot. Then it would run briefly then stop. Low rpm, barely turning. No response when pushing the accelerator. Had difficulty backing off the fuel screw locking nut due to damage to the threads from the crimped on anti tampering collar. Was able to with one from another pump. Now that the nut is backed off I can increase the fuel supply. I’ll try starting the engine again tomorrow. But is it normal to have to screw it in so far?