VX V6 Jerking / skipping problem.

[Lex]

It stayed in place when I changed the TPS.

The new tps came with the spacer?

 

[10_80]

The new tps came with the spacer?

No I used the original spacer.

 

[10_80]

that pretty much rules out ignition and fuel supply
check wiring to tps........ Checked, no damage found.
can you check fuel trims? What does that involve?
how old are O2 sensors?...... Never been changed.
have you disconnected battery and gone for a drive before it warms up fully.....When the problem first started it was only at normal running temperature, as of today the problem is there from a cold start.
Battery has been disconnected several time when fitting new parts.

 

[lout]

can you check fuel trims? What does that involve?

you need a suitable scan tool adl are not normal obd2
you can also check O2 repsonse

 

[lout]

give the maf sensor a clean, with the correct cleaner

 

[Skylarking]

Never discount bad fuel, crap in your fuel tank, partially blocked fuel filter and partially blocked injectors...

One of my cars took e a nose dive in performance after a tank of fuel. Then after some maybe 50kms of driving over a few trips, the check engine light came on with P0301 error code on scanning. It was an ODB2 vehicle so has more smarts than a VX. That code meant cylinder #1 missfire. Pulling the injector and it was visibly blocked. Emptied the fuel tank and cleaned it, flushed fuel lines and cleaned all injectors and it was good again.

Simply changing fuel filter may not be enough if the tank still has crud in it...

 

[greenacc]

I have always disconnected the battery when replacing a TPS. Then when you reconnect it and start it the ECU should learn the new sensor.

 

[mirrabucca]

OP siad: " When coasting in 4th or 5th and its given the slightest amount of throttle it begins jerking, ". My VX V6 (auto) does this if I fill with E10 or other crap fuel.
But could it be at the point where "over run fuel cut" comes in? Sort of the ECU cant decide whether to cut fuel or not? Maybe try this: put dash into the engineering mode (if it's a standard dash) or just look at the instantaneous fuel consumption readout if its a 3-window dash. Get the car to the poinjt where the jerking is happening (as you said coasting in 4th or 5th) and give it the slightest amount of throttle. Does the fuel consumption readout give a steady litres per hour (about 1.3) or litres per 100 k's (on the 3-window dash), or zero - ie no fuel being used? I would expect it to be changing between fuel being used and no fuel being used.
These cars use over run fuel cut to save fuel. It operates when the car is pushing the engine (over run) and the engine is doing (usually) over about 1200RPM. In an auto it operates in 2nd, 3rd, and 4th gears. I am not sure but I think manuals do it in 4th or 5th? Someone else can correc this.
Also, have you cleaned the throttle body and intake?

 

[10_80]

Maybe try this: put dash into the engineering mode (if it's a standard dash) or just look at the instantaneous fuel consumption readout if its a 3-window dash. Get the car to the poinjt where the jerking is happening (as you said coasting in 4th or 5th) and give it the slightest amount of throttle. Does the fuel consumption readout give a steady litres per hour (about 1.3) or litres per 100 k's (on the 3-window dash), or zero - ie no fuel being used?

Thanks for the reply, but what you're suggesting is over my head...... I've owned the car from new and had no idea the dash had these functions, even less of an idea of how to find them.

 

[10_80]

As it stands now the problem is worse, I cleaned the air flow sensor today, drove until running temp came up, problem returned......Its now also missing / jerking when labouring under part load, ie driving up a moderate hill in 3rd gear at 1500-2500 rpm, in other words when its just starting to pull, flatten it and it pulls fine.