Ongoing MAF/Running Issues

[CaptainProne]

Thanks! The car I would take it off is a scrapper and it's at the mates place I'm working on mine at Saturday, so I will try it out and update you how it goes

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[Stewarty]

I had same problem and yeah it has to be Bosch as I found out,but the car will run like crap for a bit!spose it just needs to adjust to the new maf.tell yi tho my car runs so much better with new Bosch maf (after 5 10 mins of driving)but I also get the esp light come on(oh it's a cupra r 2004)on high boost or actually it seems to be whenever I get over 100mph(on my private airstrip obviously)So maybe I still need something tweaked.apart from that the Bosch maf made a massive difference!as I found out replacing my cam sensor!used hass the 1st timeCar ran crap!changed over to BoschSorted!!

 

[Andrewwright]

I had same problem and yeah it has to be Bosch as I found out,but the car will run like crap for a bit!spose it just needs to adjust to the new maf.tell yi tho my car runs so much better with new Bosch maf (after 5 10 mins of driving)but I also get the esp light come on(oh it's a cupra r 2004)on high boost or actually it seems to be whenever I get over 100mph(on my private airstrip obviously)So maybe I still need something tweaked.apart from that the Bosch maf made a massive difference!as I found out replacing my cam sensor!used hass the 1st timeCar ran crap!changed over to BoschSorted!!

I'd say speed sensor with esp coming on at that speed. Be careful at them speeds because the abs could kick in and lock up a wheel. Happened to me at 120 about a month ago..shat myself, switching it off till I find the issue.
No code but I need to get vcds as you can test the sensors with it.

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[Stewarty]

Ok man cheers for the heads up,will switch the esp off till I get it looked at again,maybe need to find another mech as I explained to him what was hapening and he had no idea,so cheers man atleast I can look into this speed sensor!

 

[CaptainProne]

I had same problem and yeah it has to be Bosch as I found out,but the car will run like crap for a bit!spose it just needs to adjust to the new maf.tell yi tho my car runs so much better with new Bosch maf (after 5 10 mins of driving)but I also get the esp light come on(oh it's a cupra r 2004)on high boost or actually it seems to be whenever I get over 100mph(on my private airstrip obviously)So maybe I still need something tweaked.apart from that the Bosch maf made a massive difference!as I found out replacing my cam sensor!used hass the 1st timeCar ran crap!changed over to BoschSorted!!

I'd say speed sensor with esp coming on at that speed. Be careful at them speeds because the abs could kick in and lock up a wheel. Happened to me at 120 about a month ago..shat myself, switching it off till I find the issue.
No code but I need to get vcds as you can test the sensors with it.

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Ok man cheers for the heads up,will switch the esp off till I get it looked at again,maybe need to find another mech as I explained to him what was hapening and he had no idea,so cheers man atleast I can look into this speed sensor!��

Right, genuine MAF will be the first thing on the shopping list then! Regarding the esp and speed sensor that's interesting and possibly the cause of my issues too. When raising the front of the car at the weekend I had the wheel off and can see that the previous fitted speed sensors wire is too short, and doesn't fit in the holder correctly and as a result the wire looked rubbed down but in tact, thought it worked well so cable tied it in place and left it to be. But possibly it's not working as well as I thought then, I hadn't thought of that ! My light comes on after quick acceleration, and seems not to be related to the actual speed I'm doing. Possibly the quick change in speed rather than the actual speed itself is causing the sensor to throw a tantrum? Having the ABS come on at 120mph does not sound fun

 

[Stewarty]

Yip sensors for this car as I've researched and experienced are a nitemare.im having a guy who seems to know my car run a vcds scan and what I've told him about the esp light come on at higher speeds he thinks this could be the accelaration sensor(another sensor I didn't even know existed)so there's a few things to check over at the weekend!but yeah captainprone defo your best bet to get the Bosch maf in there!good luck!!and cheers to you guys for your advice,as I've bin holding her back after that wee story involving 120 mph and change of underwear!!

 

[CaptainProne]

Yip sensors for this car as I've researched and experienced are a nitemare.im having a guy who seems to know my car run a vcds scan and what I've told him about the esp light come on at higher speeds he thinks this could be the accelaration sensor(another sensor I didn't even know existed)so there's a few things to check over at the weekend!but yeah captainprone defo your best bet to get the Bosch maf in there!good luck!!and cheers to you guys for your advice,as I've bin holding her back after that wee story involving 120 mph and change of underwear!!

Stewarty, did you get to the bottom of why your ESP light was coming on after quick acceleration/boost/high speed? I'm still suffering Few updates with mine now also.

I've still been suffering with the misfire on start-up (Suggested to be the SAI) abut I've also noticed that the car as a whole was getting a bit fat (For lack of a better term) it was a bit hesitant coming onto boost, some flat spots, and it was also hunting at idle. The previous problem I had with the car starting, idling at 500rpm with no effect from pressing the throttle was also becoming a more common occurrence. The only way to get it out of this was to bump start, or roll it at a speed where in gear the revs were forced to be above 500rpm. Conveniently, the last time this happened I was around friends, one of who'm said they had a similar problem with their 1.8t and that cleaning the throttle body did wonders.

I took the throttle body off last night cleaned it and car idled like a dream! This morning I started it fully expecting it to misfire for 90 secs (Faulty SAI) and it didn't, it started it idled high and gradually got down to a normal smooth idle, and maintained it at every stop to work. It also felt a lot smoother to drive too.

So now question time, (Sorry still learning)

Is it possible that the mucky Throttle Boy was the cause of the cold misfire, and not a faulty SAI?

I left the top vacuum and bottom connector plugged into the throttle body as on the video I watched this suggested I then wouldn't have to re-align it after I had put it back on, is this true or do I need to go get it re-aligned? I was very careful not to touch the valve and had a friend put the ignition on and press down on the throttle to open it up so I could clean all of it.

The engine management light I had on showed a code P0171 - Powertrain System Too Lean (Bank 1) could this again be down to the mucky throttle body, or could this be something else?

Thanks for all your help gents, greatly appreciated.

 

[Stewarty]

Unfortunately my friend I haven't got to the bottom of it as I've bin so busy at work and as it only happens at high speeds(not high boost)I've just been taking it easy but I've also just found out my pcv system is leaking(looks like stuck valve)so next chance I get to take it in to a friend at garage we will be investigating this acceleration or speed sensor and yeah I will post the outcome on this thread and hopefully it may help with your issues.im not to sure about the re-alinging of the tb but someone on here will surely be able to help you with that.good luck bud

 

[mty12345]

Bank 1 too lean is most often a leak somewhere in the PCV system. Have a look for split pcv pipes or a broken dipstick tube. A leak here usually causes any number of hesitation and rough idle issues.

If you didn't disturb the throttle plate itself and the car idles and runs ok, then there's probably no need for re-alignment.

 

[CaptainProne]

Bank 1 too lean is most often a leak somewhere in the PCV system. Have a look for split pcv pipes or a broken dipstick tube. A leak here usually causes any number of hesitation and rough idle issues.

If you didn't disturb the throttle plate itself and the car idles and runs ok, then there's probably no need for re-alignment.

Matty, bang on again mate. Just had a look in lunch and I've got a chip in the dipstick tube, replacement ordered and should be here for Saturday. Plan for Saturday is a full service, both front lower arms replaced, rear discs and pads, and now changing out the dipstick tube!! Looking forward to it!

I made sure not to touch the plate, and yes seems to idle fine. Let's hope changing this dipstick tube will be the end of my issues!!!! Thanks again for all your help mate.

 

[mty12345]

No worries mate, hopefully that will sort it for you.

 

[CaptainProne]

Update time! may help with your issues Stewarty!

I can finally, (And happily) report my car is finally seeming to run happy, and so far with no dash lights on. I had previously cleaned out the throttle body, and at the weekend replaced the spark plugs. I also replaced the MAF with a genuine Bosch MAF and.... wow. Different car. It's so much smoother to drive, it idles better, boosts better, and when on full boost I have no tcs light coming up, so I'm guessing that the old crap MAF was the cause of that too!

Yet to investigate the PCV system, I'm waiting to do that when our weather is a bit nicer! I have no lights on my dash now, but I've read another test for the pcv is to unscrew the oil filler cap and see if its "Sucked" down? Mine jumps about indicating I've got a leak (apparently), but I'm not sure how accurate of a test this is? Regardless, I will likely have a look this weekend/next week.

Either way, I'm now a very happy man!!! Lesson learnt, genuine all the way!

 

[mty12345]

I would wait and see what happens, the **** maf could well have been the cause of the lean code.

 

[CaptainProne]

I'm hoping so Matty! Thanks for your help with everything!!!!

 

[mty12345]

You're welcome mate. Glad you've got it sorted.

 

[Stewarty]

Great news cap!yeah I was the same,new Bosch maf bit stuttery to start with but after a few miles car was much better, at high boost I was getting power surges and then found out it was Infact a burst hose and blocked check valve,changed the hoses and car has bin awsome since.have a look under your manifold as mine was obvious.good luck pal