Throttle No Response

[RobN]

I have had a problem for a while where when I start (always first time) the idle settles perfectly. However the accelerator has no effect what so ever. After waiting a short time it becomes responsive and only if treated gently.
I park Terri on the drive approx 20 degrees nose down and reverse onto the road, she normally is fine, occasionally the throttle becomes unresponsive as power is required to crest the drive.
Yesterday the problem reappeared as I drove off finally clearing after about 200 metres.
Once driven to throttle behaves properly and does not give any problems if started again. :nenau
Terri does very limited mileage now (1000 miles pa) as I have retired, sold the caravan for a motorhome and we use the Wife's Twingo for our day to day transport.
I have been trying to get a diagnostic from the OBD will start a new thread in Equipment, Modifications & toys.

 

[solarman216]

Sounds like a fuel problem rather than electrical, have you tried reversing onto your drive so it is nose up, if so was there any difference, Rick

 

[RobN]

Will Give it a Try

Thanks for the reply. This has been going on for over a year, as it clears I have not been bothered too much, hence all my mucking about with OBD.
Your suggestion is pretty obvious, I should have tried it before :doh.

The reason I have not gone fuel before is that it starts first time and the idle is rock steady and will even propel the car in 1st gear.

Rob :nenau

 

[elty001]

There's also a neutral position switch on the gearbox that I've heard cause similar issues.
Still learning the 3.0ltr myself.

 

[RobN]

Thanks for the replies.

Parking backwards does not affect the snag.

This is where I got confused:

From the manual,

"Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control, the amount of fuel injected is compensated to improve engine performance.

Idle control
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection control (Idle control)
Electronic control fuel injection pump
Crankshaft position sensor (TDC) Engine speed
Accelerator position switch Idle position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
Heat up switch Heat up switch signal
When the ECM determines that the engine speed is at idle, the fuel injection system is adapted for the idle control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the engine to keep engine speed constant. The ECM also provides the system with a fast idle control in response to the engine coolant temperature and heat up switch signal.

Normal control
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (TDC) Engine speed Fuel injection control (Normal control)
Electronic control fuel injection pump
Accelerator position sensor Accelerator position
Vehicle speed sensor Vehicle speed
The amount of fuel injected under normal driving conditions is determined according to sensor signals. The crankshaft position sensor (TDC) detects engine speed and the accelerator position sensor detects accelerator position. These sensors send signals to the ECM.
The fuel injection data, predetermined by correlation between various engine speeds and accelerator positions, are stored in the ECM memory, forming a map. The ECM determines the optimal amount of fuel to be injected using the sensor signals in comparison with the map."

Hence the reason I have been trying to get the OBDII to talk it would allow me to at least see what was happening.

Must start a new thread for OBDII.

 

[solarman216]

For my two Penarth, I would be looking at the fuel pressure regulator on the front of the pump, these can get sticky and cause all sorts of problems, the fact that it starts fine and idles fine rules out most of the electrical bits mentioned in your post, certainly a diagnostic check may help but not if it is a mechanical issue within the pump, which I think yours is, as a second to the pressure regulator air in the fuel line will also cause such problems as will water that has entered the pump in the past and started corroding moving parts (sticking over night but freeing off eventually after running a while) and then giving no more issues for the rest of the day, Rick

 

[RobN]

Thanks Rick, will check that out. "sticking over night but freeing off eventually after running a while", that would certainly explain it.
The diagnostic side was to eliminate things before I jumped in and started messing in areas I know nothing about.

Rob

 

[Banshee]

Has it ever been ran on BioDiesel to your knowledge?

 

[solarman216]

This is the pressure regulating valve, if it is sticking even ever so slightly it will need to be overhauled, the piston inside should slide against the spring perfectly, if there are signs of gum (like you see on a pressure fryer) then it will have been run on bio in the past, for some unknown reason the 3 does not like bio, (I have yet to strip a 3 pump), if there is any gum then you will need to flush the pump with a solvent, but that would be best done by a pump guy as you do not want to ruin the seals

 

[solarman216]

This is what you will see on the top front of the pump, you will need to remove the inlet banjo for access, lift the pipe high to stop fuel flowing, make sure the whole top area is washed off clean before you start, the flats are 10mm, before I bought the proper tools I tapped on a close fitting socket in order to undo it, they are usually quite tight but do not need to be, only tight enough to stop it vibrating loose, Rick

 

[RobN]

Banshee, As far as I am aware no. She was 10yo when I obtained her, from oop North (maybe the balmy Cornish weather is affecting her :lol), so I don't know what the Northerners used. Will be hoping to pick your brains ref OBDII connector soon :bow.

Rick, I was going to suggest buying a spare to try on but if you mean "167002X900 NISSAN Injection Pump" the price is .
Happy with seals (we have a Sanctuary at GweeK :thumbs:doh). My earlier life as a Navy Air Eng covered lots of Hydraulic messy stuff.

Rob

 

[RobN]

Sorted

Finally got ECU Talk to work.
http://www.nissan4x4ownersclub.com/forum/showpost.php?p=373890&postcount=184

There were 30 errors for throttle position sensor the problem has not reappeared since my last post so I will park the fault :augie for now and see if I can source a replacement.