Hi guys, had the intermittent problem above, then it happened twice yesterday so thought id try get to the bottom of it!

 

My mk1 vrs went into limp mode, so i turned her off and on again (which usually sorts the problem) but yesterday when I restarted it, the throttle was stuck at around 2k rpm and there was popping from the exhaust…I imagine from the extra fuel. in the past, my snap on tool has flagged up logged error codes around the thermostat and advance cam timing, so im thinking either faulty thermostat or cam sensor?

 

any thoughts or advice welcome!!

Any lights on the dash? Have you checked the coilpacks too?

What codes are appearing on your Snap-on tool?, when you say relating to thermostat, what code is it showing?.

 

I am guessing by the pipework, that you have a front mount intercooler fitted, is all the pipework pressure tight from leaks?.

 

What does your temp gauge show when warm?, a steady 90 degrees or does it fluctuate when driving, especially downhill?.

 

Are you running the standard map sensor on your intercooler piping or the modified Golf unit?.

 

 

 

 

Nope no lights on the dash… typical VAG!!

 

I can’t remember exact codes, but it mentioned advanced cam timing and the error in thermostat reading.. the cam timing could be down to it being remapped (as i know they advance the timing in the map) 

 

Yep have a fmic fitted.. there’s no issues with boosting, but no harm in borrowing my mates smoke machine.

 

Temp is fine.. goes down to about 65c when fans kick in, havent noticed anything up or down hill (what would that mean anyway out of curious?)

 

as far as im aware the standard map sensor is fitted, but i do have upgraded fuel pump and pressure regulator (aps265)

The temp gauge should get to 90 degrees fairly quickly from cold (usually about 1-2 miles) and stay there without any fluctuation, fans or not, unless it is standing in traffic. If it does rise and fall, that can be an indicator of a failing thermostat.

 

Having said that a gauge sensor can give similar faults as the sensor serves 2 funtions - 1) to tell you the temp of the engine, and 2) to tell the ecu to the engine the coolant temperature.

 

The sensor is split in half as far as function is concerned, which basically means it could possibly be giving a good gauge reading and a compromised ecu signal, or vice versa - which is usually the more common way that the sensor fails. This was why I asked if you knew what the code was, to try to eliminate sensor from thermostat failing.

 

You basically are really looking for either failed sensors or unmetered air getting into the system that the ecu is trying to correct for I would think. Just out of interest, has it got a decat on it or is it on a sports cat?.

 

It looks like a lot of the SAI and breather pipe mods have been carried out from the photo, so there are less pipes and valves to be temperamental, but I would still spend 5 minutes with a torch and a small mirror to make sure a blanking bung has not become displaced under the manifold. As most of the stuff that would normally be in the way has been removed on yours, that should be fairly easy to check and it will cost you bugger all.

 

You could also get some live data from VCDS if you know someone with it to check the MAF sensor is reporting correctly, and is not dirty or failing.

 

Has the throttle body been cleaned in the last year at all?, as that can cause sticking rpm, but in all honesty I don't think it is the majority of your issue.

 

Try to do some of the checks and let us know what you find so we can try to help more,

Edited 12 March, 20224 yr by kentphil1