Hi all,

My 1.9 tdi has suddenly lost acceleration on startup. It drives like a tractor until I rev it up to around 3000 for a bit then it suddenly clears and is fine until the next startup. I unplugged the maf and it was back to normal, so took the maf out and gave it a bit of a clean. The car suddenly went like the clappers, faster than ever, although was stalling at first moving off. This morning I tried it again and the same old struggling acceleration is back.

 

I presume that the unplugging test definitely points the maf being at fault.  Is there anything else I should check first before buying a new one? And will any maf do, or are there any to avoid?

I'd appreciate any pointers. Thanks

Yes sounds like the maf, just replace it for a new genuine one. If its the original then its due a change by now

Buy a genuine Bosch MAF, not a Chinese knockoff.

12 minutes ago, sepulchrave said:

Buy a genuine Bosch MAF, not a Chinese knockoff.

 

Definitely! don't let the cheap eBay MAFs lure you in, they are garbage and you will need another within a week

Thanks all. Bosch it is then. I'd have bought a twenty quid job from ebay so I'm glad I checked.

25 minutes ago, magoorty said:

Thanks all. Bosch it is then. I'd have bought a twenty quid job from ebay so I'm glad I checked.

Glad you decided to change your mind. In general it is not a good idea to skimp on engine management components.

I'm now completely flummoxed. I've been running the car with the maf unplugged for a couple of weeks with no issue. Finally got around to plugging in the new one, and it was running as badly as before (no turbo til about 2800 revs). I unplugged the battery for a bit longer then let the car idle for 30mins. This time it drove just like it did after the old maf was cleaned (and battery disconnected etc), more acceleration but acting up in first and prone to stalling. Turbo is all over the place. Do new mafs tend to work straight off?

59 minutes ago, magoorty said:

I'm now completely flummoxed. I've been running the car with the maf unplugged for a couple of weeks with no issue. Finally got around to plugging in the new one, and it was running as badly as before (no turbo til about 2800 revs). I unplugged the battery for a bit longer then let the car idle for 30mins. This time it drove just like it did after the old maf was cleaned (and battery disconnected etc), more acceleration but acting up in first and prone to stalling. Turbo is all over the place. Do new mafs tend to work straight off?

 

Of course, unless they're duff.

5 hours ago, sepulchrave said:

 

Of course, unless they're duff.

Bought a Bosch one from Amazon so I'm presuming it's not a duffer but you never know. No idea what to try next.

Edited 5 December, 20178 yr by magoorty

Unplug it and see if it improves, I have no idea why you would disco the battery and then let it tick over for 30 mins, it doesn't have a Lambda probe because it's a diesel so you just wasted a bunch of time and fuel for nothing.

12 hours ago, sepulchrave said:

Unplug it and see if it improves, I have no idea why you would disco the battery and then let it tick over for 30 mins, it doesn't have a Lambda probe because it's a diesel so you just wasted a bunch of time and fuel for nothing.

 

I know nowt about cars so I've been following what I read online. I read that it's a good idea to reset the ecu after changing the maf, so I did this - https://www.briskoda.net/forums/topic/201016-how-to-reset-the-engine-ecu/

 

Anyway, I've unplugged the maf (a pain as I've knackered the clip) and the car is back to normal. So the symptoms are exactly the same with the new maf as with the old one and disappear when unplugged. Could it be a wiring fault on the connector, or would that be more intermittent. I'm at a loss here.

17 hours ago, magoorty said:

Bought a Bosch one from Amazon so I'm presuming it's not a duffer but you never know. No idea what to try next.

maybe it was Bosch (shengzen div)  I would either use the local Bosch depot or if desperate the stealership   Amazon e-bay, ali ex'   ----what's the difference?   

My advice is have your local garage check the car out ? You seem to be at a loss as to what you are doing with your car?

Join the AA or the RAC safes a lot of time ??? and money

TB2

Edited 6 December, 20178 yr by TB2
bad gramer

Sorry for this but these are the exact same symptoms my jeep patriot had before jeep engineers / tech balls it all up. It had the very same VW pump duse engine in 1998cc form. It was a mash up with Chrysler and VW in the early 2000's. 

 

It'll through up MAF sensor codes etc. But I'm 99.9% certain you'll find its the EGR hose has collapsed internally. You won't find a thing if you remove it and take a look as it only collapses when under vacume, and then it's only the inner part of the hose construction.  I think they call it a double ply core construction. 

 

Symptoms will be rough running at idel, black smoke on acceleration, poor mpg, MAF sensor fault codes, better running when disconnected, possible blocked fuel filter symptoms, rough running, stalling, poor acceleration and general rubbish-ness. If you do a jeep patriot search and then for the 2.0 limited diesel there'll be loads of stuff about this issue. 

 

Hope this helps.

 

 

Thanks for that, I'll definitely investigate. Cheers

not the same engine?

to rule out any egr issues, you can remove the vac hose from the valve which will stop it operating. It may also throw a fault code but at least you will be able to see if its the egr causing the issue

its the top left on this photo the 'silvery/gold' coloured part with the hose on it.

Edited 7 December, 20178 yr by clarendon462

That's handy advice. Thanks.

If its the EGR it is likely that disconnecting the rubber/silicone hose to the far left of that photo will allow you a glimse (with a torch) of the EGR. 

If there is lots of black oil solid gunk it is possibly the EGR. My EGR blocked in the open position and caused smokey exhaust and a rocking engine (seen with bonnet up) on idle which stopped when revving the engine. EGR for fabia 1 vrs was £100 - £115 so I bought new with new seals (some seals are included with the part so check the workshop diagram at dealer). They will e-mail you or TPS. 

I think it was allen key job for the screws. There is a guide on Briskoda involving an EGR delete but it was useful for replacing EGR to a point.

 

My MAF had gone around the same time as EGR, although the local INDY used diagnostic machine (no codes) but noticed the air flow reading (MAF) was not sending any information. Cable was connected. I tried cleaning MAF (reports of some success with electrical contact cleaner) but it didn't help. 

Bought a new genuine one from Andrew Page. Always buy electrical stuff that are genuine, OEM good name or dealer/TPS. Mine was a reconditioned Bosch.

 

Matt

On 07/12/2017 at 17:12, cheshire_cat said:

not the same engine?

 

From 2009 Chrysler moved to the 2.2 Merc TD engine. Prior to that it was the VW duse pump engine. Trust me I had a 2008 heap. When it broke down  Jeep techs had to get spares from the local VW dealer.  I even went to my local VW dealer for service items as they were cheaper than Chrysler.

 

https://en.m.wikipedia.org/wiki/Jeep_Patriot

 

 

2 hours ago, TripleMcB said:

 

From 2009 Chrysler moved to the 2.2 Merc TD engine. Prior to that it was the VW duse pump engine. Trust me I had a 2008 heap. When it broke down  Jeep techs had to get spares from the local VW dealer.  I even went to my local VW dealer for service items as they were cheaper than Chrysler.

 

https://en.m.wikipedia.org/wiki/Jeep_Patriot

 

 

i think @cheshire_cat means it was the 2.0tdi which is a different engine to the 1.9

Ah, I see, apologies. The jeep was still rubbish

Did this issue get resolved? My vrs keeps jumping in and out of boost with light on showing maf open or short to ground. Changed maf twice still loss of power any ideas?