OK, Start the car from cold, everything is fine. RPM at 1500rpm and all other gauges are fine.

So, I select reverse and as soon as I touch the accelerator the revs drop by 500RPM! I then have to over rev to compensate so as to avoid stalling! This goes on untill she reaches normal operating temp, then the reverse happens! Sits at 850 RPM and as soon as I touch the accelerator the revs jump up 500RPM!!

I'm begging you guys, can someone tell me how to fix this? It's making driving bl@@dy hell.

The only thing that I can say is, that there is a definite click each time I touch the accelerator and it seems to be coming from the right side of the drivers footwell.

Give the idle speed adjuster valve a clean, passenger side back of plenum. Good place to start as they can get gunked up

Thanks mate,

The thing is, if I leave her ticking over from cold, as the engine reaches temperature the RPM drops gradually and settles at 850RPM. This leads me to think that the valve is OK, will clean it as you say though, as a process of elimination.

Edited July 8, 201213 yr by redwine300

Manual or auto? Im guessing auto and maybe in need of a oil change.

UK manual mate, 1992 tt?

Revs jump up or down even when in neutral. The slightest touch of the pedal and off the revs go!

Something tells me that the position of the throttle communicates with the ecu or some other sensor.

One of which is playing up?

Edited July 8, 201213 yr by redwine300

Idle should be about 900 rpm when cold and between 650-750 once warmed up iir

1500 when cold is too high, also check tps to correct voltage

Try setting the tps and then reset the base idle :)

Cheers Hellraiser,

Will check the tps voltage tomorrow.

Did have it set at Zedworld 6 months ago so should be good though.

What's causing the clicking in the footwell do you think?

 

Thanks also rebel scum.

Edited July 8, 201213 yr by redwine300

maybe you should be checking up in the foot-well to make sure you aren't crushing anything....

Footwell clear, I have had my ear down there and it is definitely coming from behind the fuse box cover.

Driving me nuts!!

 

- - - Updated - - -

 

Footwell clear, I have had my ear down there and it is definitely coming from behind the fuse box cover.

Driving me nuts!!

Air con switching on and off?

Footwell clear, I have had my ear down there and it is definitely coming from behind the fuse box cover.

Driving me nuts!!

 

no I mean check that the pedals aren't pushing on any wires...

Check the 2 temp sensor connectors on the top water pipe for corrosion , a bad connection on one or both of these can cause wierd symptoms bud . HTH

Cheers guys for the input thus far. I will check out your suggestions at the week end.

I need to solve this before the men in white coats come for me!

Hi Ianl, Checked air conditions and all is switched off, thanks for the input though.

 

As for the pedal coming into contact with wiring Medallion man, all clear mate.

 

Cheers Boldy, the wires to the temp sensors were a bit iffy, cleaned and re fitted but to no avail I'm afraid.

 

Decided to connect Data Scan and see if I could see anything odd. One thing that was apparent from the off was the TPS read OFF at tick over, but as soon as I touched the throttle pedal in changed to ON. (Clicking in the foot well corresponded with the on/off switching.) Normal???

 

Secondly, I noticed right hand O2 sensor was fluctuating between 25 and 35 settling around 42 when warm. Left hand sensor just sat at 32 and never moved from cold to hot. seems odd to me.

 

Also, I watched the AAI % drop down to 20% and the tick over settle around 800rpm once warm. As I revved he slightly, the revs dropped and and then recovered, just!! and at the same time the AAI % shot up to 45% Is this normal??

 

Something definitely note right if you ask me.

 

Desperate to get it sorted.

Bump!

 

 

Decided to connect Data Scan and see if I could see anything odd. One thing that was apparent from the off was the TPS read OFF at tick over, but as soon as I touched the throttle pedal in changed to ON. (Clicking in the foot well corresponded with the on/off switching.) Normal???

 

Secondly, I noticed right hand O2 sensor was fluctuating between 25 and 35 settling around 42 when warm. Left hand sensor just sat at 32 and never moved from cold to hot. seems odd to me.

 

Also, I watched the AAI % drop down to 20% and the tick over settle around 800rpm once warm. As I revved he slightly, the revs dropped and and then recovered, just!! and at the same time the AAI % shot up to 45% Is this normal??

 

Something definitely note right if you ask me.

 

Desperate to get it sorted.

Right, so you have checked the TPS with a volt metre (I assume).

I can send you my spare one for you to test (you can then send it back to me if it's not the fault).

 

The O2 that is fluctuating is fine but the other one seems to have an issue.. try unplugging it (and check the connections again)... this may be of interest..

http://www.pexcom.com.au/z32cms/e107_plugins/content/content.php?content.296

 

AAI should be at about 15% at temp (20 isn't too bad) but it "will" move about, because it controls idle... so it don't think that is a problem but the cast that it's slow might be.

 

Have you taken it off and cleaned it? (there is a write up on how to do that).

 

I also have a couple of spares and could send you one along with an O2 sensor. (I understand that they are a bit hard to change http://www.pexcom.com.au/z32cms/e107_images/Replacing%20Oxygen%20Sensors.pdf ).

 

If you're happy to pay for postage and then we can sort out whatever you want if the new part works.

Hi Medallion Man,

 

Checked TPS and the reading came back as 0.46 volts, is this high?

The offer of a known good unit to try would be more than welcome, very generous.

Very happy to cover any costs and inconvenience, will even throw in beer money mate.

 

The 2 links are great by the way, they have given me a lot to check out.

I am going to put some time in today so as to check everything suggested with regards to testing both O2 sensors. (if I can locate the bl**dy connectors that is)

 

I hope that they check out OK! Do not fancy tackling removing them, scary!!

 

Can't thank you enough by the way Medallion Man.

 

I'll be back later with my finding. (fingers crossed.)

I had the same problem a few months back and mine turned out to be the MAF unit I tried one of the ebay ones but these dont work to well so I got my self a decent second hand one and all is good. If you have one or have sopme one near by that can just let you swap as a check I think you might find this sorts it

Hi Ceejay, Sounds promising.

I am that desperate to get to the bottom of it I will try anything!!

I did have a possible intermittent problem with the MAF some time ago! maybe a coincidence, who knows?

Got to be worth trying a known good one, if only to eliminate it.

 

thanks mate.

Spent a couple of hours checking and cleaning connectors throughout so far.

A good thing came of this in as much that I found out where the clicking was coming from.

It is one of the 2 solenoid valves next to the boost gauge sender unit. (the lower of the two I think, will need to confirm though)

One of the 2 solenoid valves got quite warm within a few minutes of running. (the right hand side one of the 2, EGR valve solenoid?)

I went round several like for like solenoid valves and they were all cold.

Would this sugest a problem with the selenoid or a more sinister fault?

Well, after hours of cleaning and scraping as many connectors as possible. I decided to re try Data Scan.

Nothing changed really apart from one thing, Both O2 sensors read 32, only slight difference was that when I raised the revs, one stayed at 32 and the other fluctuated between 30 and 32. I would have been happier if both had reacted the same though.

 

As for the dodgy solenoid, I left this off during the scan.

 

So decided to re connect it and go for a short run, not sure if it was my imagination or frustration, but she did feel bl**dy quick, After 15 miles or so I arrived back home, adrenaline levels a tad high, so before I put her in the garage I checked the re connected solenoid. Could not touch it, it was that hot!!!!

What could be causing it to get so bl**dy HOT??