Erratic revs & idle after fitting filter

[owen lcr]

ok i fitted a dbilas filter to my cupra on thursday night but today is the first day i have used it, i was just out for a pacey run with the car but when i slowed down to the town speed of 30 the revs were very irratic, then when i puled into my drive way and the revs were supposed to sit at idle (900rpm) they jumped about all over the place from 400rpm to about 1200rpm...
i can only think it may be a sensor on its way out. maybe a idle control valve or MAF

any ideas

thanks, owen

 

[DanGB]

must be the maf sensor if youve just changed the intake. Have you checked it is in OK condition?

 

[owen lcr]

well it looked ok when i took it out to fit it into the new intake but mite still be goosed.. any idea how much a maf is???

 

[DanGB]

Sorry dunno, i'd have another look at it now, seems a conisidence that its gone funny just after you changed the intake, if it is that at fault.

I don't really know about the idle contol valve.

 

[Tam]

Is this filter oil coated?

Seem to remember other posts about how an oil coated air filter screwed up a MAF .. would certainly make sense though

 

[owen lcr]

erm to be honest i am not sure, i know igor has got the dbilas filter and dont think he has had any problems... is there any way tho find out if it is the maf that is faulty

cheers

 

[Tam]

Vag com logging i believe, check out the vag-com fourm or search the Mk1 leon section as plenty have gone in there.

Or contact DPJ who (IIRC!) has killed about 9 in 2 years

 

[Igor23]

Did you leave the engine ticking over for 10 mins, prior to driving the car, to recalibrate the MAF sensor??, also, you didn't touch the surface of the sensor...

 

[owen lcr]

i left the car running but not for 10 mins i had never heard of that before, but i did make sure i didnt touch the sensor so i am not sure what it could be... do you think if i start it up and leave it for 10-15 mins it might sort itself out.

i just started it up to go and get my tea and the idle was all over the place for about 5 seconds then it sounded like it was trying to suck a massive amount of air, then it started to splutter...

sounds bad but it has to be the MAF because i have never had a problem until i put this filter on and the MAF is the only thing that is affected... i am not blaming the filter but it may be that i didnt leave it long enough???

 

[Al]

Withoot going in to details, I think neither of us wid be surprised if something got broken with regard to idle/air control/mass air flow sensor on your wagon bud.

I can VAGCOM it for you, but we will need to figure out what we are checking for first.

 

[owen lcr]

yeah, where do we start, and what do we look for when checking a MAF using VAGCOM

 

[Al]

Would have thought that a fault would be obvious, and the air flow can be logged again. A question in the VAGCOM section may be appropriate. You should explain the fault in there and someone may be able to help.

 

[owen lcr]

i was just wondering what the symptoms of a DV failing are.. do you think this could be the caus

 

[Al]

Which one are you running? You said you were going to put the Forge back on? Swap out whatever one you have on at the moment to try and rule that out.

 

[owen lcr]

i am running the standard one at the moment so might take it out tomorrow and have a look to see if that is the problem... if not we will need to try and hook up vagcom if thats is ok for some time this week mate

 

[Al]

Any time. Just give me some warning.

 

[DanGB]

Would be nothing to do with the DV, or the turbo for that matter, as no boost is involved.

The symptom of a failed DV, is lack of boost when car is on load, possibly some fault codes as well.

 

[John Cupras]

Would be nothing to do with the DV, or the turbo for that matter, as no boost is involved.

The symptom of a failed DV, is lack of boost when car is on load, possibly some fault codes as well.

I agree with DanGB and I think you should check the electric connector of the MAF.

Using the Vagcom you should check how many gr/s is the MAF meters.
Another issue may be the wrong installation (please no offence), I mean there may be a air leakage so MAF doesn't meters all the incoming air.

Finally I don't think is the air-filter's oil as you only have it for a couple of days.

 

[owen lcr]

i have went over the whole installationa couple of times and all is very secure and i cant find any leaks, is there any way to try and clean the MAF?

 

[John Cupras]

i have went over the whole installationa couple of times and all is very secure and i cant find any leaks, is there any way to try and clean the MAF?

Two more think you can try:

1st: Try to clean the MAf with contact cleaner spray WITHOUT oil of course remember NOT to touch with any material the sensor inside ... just spray it with the cleaner and let it dry.

2nd: Using the vag-com go to the group 032 and see (while idling) if there is any correction (it shouldn't) and if so there is an air leak somwhere AFTER the MAF.

Slightly Offtopic: Which kit did you installed as I am interested in buing it. (part No please if have any , thank you)