Technical Please help!! Egr?? Maf??

[will0369]

I have found some very useful stuff on here including how to clean my EGR valve (thanks for that), but i'm still having a nightmare! If anyone could shed some light on the situation i'd be very grateful.

Please allow me to bore you with the details.

I have a y reg multipla which was first driven many miles with a blocked cat (before i got it). It was running fine in low revs but not going higher than around 3500. We removed the cat put it on the computer which showed a faulrty MAF sensor. So as this is apparently common we replaced that and that got us around 4000 revs. I had to drive it around for a while before doing anything else and the revs once again dwindled.

This is where i followed the extremely helpful 'how to' on here and cleaned out the (completely blocked) EGR. It has now gone to it's lowest revs of all at 3000 and is even sluggish in the lower revs, wheras it never was before.

I'm at my wits end and have my brother and his family coming to visit next week and i really need the car! Please help!

Thanks in advance

 

[will0369]

I also forgot to mention that it is now kicking out a huge amount of dark smoke, i'm no pro but i'd suggest burning oil

 

[cooky257]

Hi, sorry I don't have a definative answer and I am not an 'expert,' but here are my experiences. I replaced my Maf with a cheap pattern part off ebay,I had to because I damaged the original trying to clumsily clean it, the new one didn't work properly, the power delivery was completely different and it didn't rev properly. Only a geuine Bosch MAF with the correct part number for your model works properly.
Cleaning the soot out from the EGR is only half the problem, the solinoid corrodes internally and sticks either open or closed. The best solution is probably a replacement. If you can connect the car to Fiat ECU scan, you can actuate the solinoid remotely,it can be heard clicking if it working.
Not sure about the smoke, it could be related to the EGR but maybe some diagnostics like FES would help.

 

[momoe]

Sounds like the turbo isn't kicking in, black smoke would be unburnt diesel (oil smoke is blue).
You don't mention if the engine management light is on, I'd suspect either the boost sensor or the MAP sensor but I'd get the diagnostics read first to hopefully give you an indication of what's not happening.

As Cooky says, cleaning the crap out of the EGR is one thing, if the solenoid is ballaxed then it's all for nowt as the ECU will put you in limp mode if the solenoid doesn't actuate.

I'd also check the hoses from the turbo to the intercooler and from intercooler to inlet manifold for integrity, the other hose to check is the small red one from the turbo to the boost sensor to the low left of the battery box, this is a vacuum hose and any leaks will result in turbo not working properly.

 

[will0369]

Thanks guys, i've already checked all the hoses except the red one which i'll go do now.

Do you think that the solenoid or turbo may have packed up after i cleaned the EGR? There's still no engine management light. It seems like a strange coincidence that they would go right then. The fact that symptons have got worse straight after my 'repairs' make me now start to wonder if i've created myself a new problem! I'm going to check all my electrical connections again and see if that helps.

At least the sun is shining, it always makes it that bit easier...

 

[momoe]

EGR not working should throw up an engine management code, in the absence of an engine management fault then disregard the EGR for the time being (If you're happy that it went back together ok and you haven't got any leaks).
Disconnect the MAF sensor and see if the fault changes/disappears, you need to eliminate the MAF as it's also something that has been changed.

 

[disgusted]

There's also something called a "turbo actuation valve". If that packs up you'll get sooty smoke.

 

[will0369]

Hello again all, sorry for not replying to your helpful messages before. Unfortunately work took over for a while and with the loan of a working car i was able to stop thinking about this headache for a while!

In this time i sent her away to a mechanic who replaced the turbo, which looking at it, was clearly in need of doing. However he had no real interest in any further diagnosis when it didn't seen to make a great deal of difference. I got the diagnostics done a couple of days ago and they showed up only a faulty water temperature sensor. I have changed that, reseated all the hoses and things have improved further still however i'm still having to rev up to about 3500 before getting the turbo. Any ideas if this is possibly going to be the sensor that controls the valve on the turbo?

Cheers

 

[Dcthebear]

Unplug the MAF sensor and see if it kicks the turbo in. If not it could be the waste gate stuck open which will bypass the turbo.