VL problems - what next !!

**skookumchuck** · 11-02-09, 05:40 PM

well i'm at a loss. i've done the injectors, replaced the fuel pump, filter, coolant temp. sensor, distributor, coil , timed it, cleaned and sprayed all the terminals. etc. etc. started it up, fine. went for a drive and it started doing it again !!! as soon as it goes into top gear it starts chugging. i go up a hill fine going up and when i get nearly to the top i ease off the accelerator and it changes into top gear and starts chugging. it's when i ease off the accelerator that the problem starts. it just won't keep into gear and wants to change into top gear even when doing 50kph. it just won't hold. i've checked the computer and it flashes 14 times which reads the 'veh. speed sensor system'. it's got to do with that, but what do i do about it ? any ideas anyone ??

**Godzilla** · 11-02-09, 07:40 PM

It wont keep the gear you want to your throttle position is something else.

Not kicking down is the detent switch switch under the accelerator pedal not working.
Get under your dash and check that it works when you floor it, its adjustable.

Not selecting the correct gears and not down shifting up hills is the throttle valve switch on your butterfly shaft, its actually a throttle position sensor that reads your pedal position and sends the output signal to the ECU which sends the gear position command the the auto transmission. The TPS are known to get oil inside, either replace it or you can remove it, drill out 2 rivets, open it, clean it with contact cleaner and re glue the cover back on and readjust its position as per owners manual.

Check your connections and wire looms while your there, the cars are getting a little old and grey.

My moneys on you throttle position switch (TPS).

**skookumchuck** · 11-02-09, 07:51 PM

okay i'll give that a try and i'll let you know. didn't know much about cars till i bought the wife the VL back in '96 ! am just about full bottled now !! thanks for replying

**Godzilla** · 11-02-09, 07:55 PM

Just one other thing, one thing ive overlooked is the ECU its self.

Do that last, if your in Melbourne, Pick A Part in Camberfield has some VL's, parts are cheap, when paying just say "some switches and a ECU", the guy will pause and not know what the switches are most likely and charge you for the ECU+a few $ for the lot.

I still think its the TPS if its a gear to throttle position problem.

And check your speed sensor.....obviously.

**Moof** · 11-02-09, 08:07 PM

I have had some experience with throttle position sensors. I have found that they wear out, usually around where the throttle is just open. That is where most driving is done. Remember old TP sensors are just a pot and the wiper has rubbed backwards and forwards alot of times.
If you can get one for free or cheap second hand and it fixes your problem I would sugest getting a new one as the old one has done probably the same amount of work.
Make sure you get a genuine one not a cheap crap chinese one as it will not last.

Good luck

**skookumchuck** · 11-02-09, 10:33 PM

i do have a spare ecu. that will be the last resort. i have one of the srew/ nuts off the throttle position switch but the other is so difficult to get at. if that is the TPS where is the speed sensor ? is it behind the speedo ?

**skookumchuck** · 11-02-09, 10:36 PM

yeah you're right moof i'll try and get a new one. don't want to go through all this again ! that's if i'm getting the TPS off. is it to the right hand side of the air intake with two contact clips attached ?

**Godzilla** · 11-02-09, 11:49 PM

Tps is connected to your throttle butterfly shaft.

When you pull the accelerator cable a shaft it turned, on the end of the shaft is a electrical unit that measures how much the cable has turned the shaft.

That unit is your TPS.

**intelliGEORGE** · 11-02-09, 11:59 PM

Sounds like the VSS (vehicle speed sensor) may be intermittent. It's an optical sensor in the back of the speedo head assembly in the cluster.

Check the wiring as these problems come down to only a few possible causes,

1. Open circuit (or partially open which causes high resistance)
2. Short to power
3. Short to ground
4. High resistance (usually caused by corrosion or poor connections)

If you can get hold of a new sensor and measure the resistance across the contacts, you can use that as a reference against the readings of your sensor.

Being an optical sensor, it may just be dirty.

**skookumchuck** · 12-02-09, 03:40 PM

have changed the throttle position switch, (TPS )with no difference. idles a bit faster and still intermittent chugging when i ease off the accelerator. as i pulled into the shed on idle it would just about die then 'broom' up she'd rev again , die then up rev up and kept on doing that as if someone was pumping the accelerator. ?? not much left to check ??

**skookumchuck** · 12-02-09, 03:43 PM

Originally Posted by intelliGEORGE

Sounds like the VSS (vehicle speed sensor) may be intermittent. It's an optical sensor in the back of the speedo head assembly in the cluster.

Check the wiring as these problems come down to only a few possible causes,

1. Open circuit (or partially open which causes high resistance)
2. Short to power
3. Short to ground
4. High resistance (usually caused by corrosion or poor connections)

If you can get hold of a new sensor and measure the resistance across the contacts, you can use that as a reference against the readings of your sensor.

Being an optical sensor, it may just be dirty.

am waiting to fit another speedo in as the odometer doesn't work so i'll check the optical sensor and clean it before i put it in. cheers for that. i just can't figure out what's causing it. got me stuffed !

**Godzilla** · 12-02-09, 05:16 PM

Originally Posted by Godzilla

I still think its the TPS if its a gear to throttle position problem.

And check your speed sensor.....obviously.

My first guess was wrong...but you were warned about the speed sensor.

**intelliGEORGE** · 12-02-09, 10:00 PM

Originally Posted by skookumchuck

am waiting to fit another speedo in as the odometer doesn't work so i'll check the optical sensor and clean it before i put it in. cheers for that. i just can't figure out what's causing it. got me stuffed !

The vehicle speed sensor works off your speedo cable where it enters the dash cluster. If you say your odometer is not working, chances are there is the problem.

**skookumchuck** · 12-02-09, 11:04 PM

Originally Posted by Godzilla

My first guess was wrong...but you were warned about the speed sensor.

yes i am going to check the speed sensor when i get the speedo i have bought. i need to replace the odometer. i have checked the AFM and pulled off the plug and it nearly died but kept going not idling quite so fast though and when i worked the accelerator cable it was as if someone was pumping the accelerator very intermitent. when i pulled off the whole thing i couldn't start it. could it be stuffed ?

**Godzilla** · 13-02-09, 12:51 AM

Could be, id be checking the connections before getting carried away first.

One other thing, disconnect your battery for a few minutes to reset the ecu and clear any old codes out.

**skookumchuck** · 14-02-09, 12:57 AM

Originally Posted by Godzilla

Could be, id be checking the connections before getting carried away first.

One other thing, disconnect your battery for a few minutes to reset the ecu and clear any old codes out.

had a look at the afm and there are supposed to be heat wires in it but i couldn't see one. went to the wreckers and there's was the same as mine and the owner said it was stuffed . so i'm waiting on another one. keep you posted

**skookumchuck** · 17-02-09, 01:29 PM

Originally Posted by Godzilla

Could be, id be checking the connections before getting carried away first.

One other thing, disconnect your battery for a few minutes to reset the ecu and clear any old codes out.

If the AFM heat wires have gone can they be replace or fixed. i do remember it backfiring and before that they were all there intact. but not now. so i still have that sensor problem plus the heat wire problem as well. both are getting fixed this week i hope when they arrive.

**Godzilla** · 17-02-09, 06:45 PM

Im questioning what the heck is wrong with your wiring and connectors to have burnt out your AFM when all you have done is clean it and play with your plugs.

You didnt clean it with contact cleaner and plug it back in while it was still wet?

**skookumchuck** · 23-02-09, 06:05 PM

Originally Posted by Godzilla

Im questioning what the heck is wrong with your wiring and connectors to have burnt out your AFM when all you have done is clean it and play with your plugs.

You didnt clean it with contact cleaner and plug it back in while it was still wet?

no , it was when we put the dizzy back it was 180 degrees out and it backfired blowing the wires out. still waiting for the other AFM to come in the post. should be here this week !! then i'll get stuck into it.