Hi everyone. I'm hoping you would be kind enough to share some of your knowledge with me. I bought a 115 jtd multiwagon just over a week ago and i'm having a couple of issues with it.

1. It seems to lack serious amounts of power below 2500 rpm, above 2500 and it goes like stink, however if i hold it in a gear at say 3000rpm while pulling up a hill i get an "engine fault" message and the engine management light comes on. It then wont rev over 3000rpm. After several restarts the light goes out and it will rev higher again. The fault code generated is P0236.

2. The second problem i'm having is that sometimes (getting more frequent) when pulling away from a standstill it struggles to rev up at all, there is no knowing when its going to do it and to be honest its quite dangerous when pulling out of road junctions etc. After crawling along the problem suddenly clears and off i go leaving a big cloud of black smoke behind me.

I've had it back to the supplying dealer, he has cleaned and moved the pressure boost sensor, both problems still persist. I asked him if it could be a MAF sensor fault because when i un plug it problem 2 is cured, but not problem 1. Apparantly they fitted a new one from euro car parts before i bought the car. Not sure if its relevant but when i unplug the MAF i dont get an engine management light?

Has anyone had a similar experience who could offer me some advice, could there be something else thats maybe causing me these problems (EGR or MAP?) Any advice greatly appreciated

The first issue sounds like the boost pressure sensor, so check all the pipework running to/from isn't split, and check the hoses running from/to the intercooler. If they're all ok, I'd replace (had exactly the same issue and after much faffing about this is what it was.

The second fault sounds like the EGR valve. Remove, clean the blank it off. There are guides for both of these on the site.

ferritt said:

I've had it back to the supplying dealer, he has cleaned and moved the pressure boost sensor, both problems still persist.

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The boost pressure sensor is the MAP sensor. You can't move it, it's fixed in the inlet manifold.

I suspect it's the boost valve they've moved. It was a Fiat modification to move it to the side of the battery box to prevent water getting into it.

Clean the MAP sensor. (carefully)

Your first problem is due to a loss of boost, most likely its due to a split or cracked high pressure induction pipe.

Your second problem is due to your first problem. Because your loosing boost the MAF sensor is detecting far more air flow than is normal so the EML comes on. The reason the EML doesn't come on when the MAF is unplugged is because the car is not able to detect the extra airflow once its unplugged.

Check the induction pipes, high pressure side. Also check the intercooler for leaks.

I suspect your dealer moved the "Boost Control Valve" not the boost control sensor.

Thanks for all your advice, yes it was the boost valve they moved from under the wheel arch, my mistake. I've checked all the hoses for leaks and all seems well. Is there a way to test to see if the boost valve is operating correctly? If its stuck would it cause poor performance low down in the revs and then generate too much boost higher up the rev range.

Shadeyman, i understand what your saying about the maf sensor picking up the extra airflow however i still get the eml on and code p0236 even with the MAF sensor disconnected, could this mean the MAP sensor is generating this code?

I suspect the MAF sensor the dealer fitted isn't a bosch one, could this be an issue, I've got it un plugged again so as to get rid of problem 2, which is making thr car dangerous to drive.

Sorry for all the questions

From my experience, the MAF doesn't give a fault when disconnected, but does give one if returning out-of-range readings. However, once the fault has been generated, you can't clear it without fitting a working MAF.
Running without a MAF or with a faulty one affects MPG a bit, but not significantly enough to make the car "dangerous" or even noticeable when driving.

Just a bit of an update, new bosch maf sensor fitted, egr and throttle body cleaned. I seem to have cured the over boost problem (eml code p0236). I'm still having intermittent issues with the car bogging down when setting off from a standstill and it wont rev up cleanly. If i dip the clutch and rev it up a bit its then ok, like wise it doesn't do it if i rev it up a bit whilst setting off and slip the clutch slightly. I think my next port of call will be to replace the turbo boost valve and or clean / replace map sensor. Is there anything else i should be looking at?

I've also considered blanking off the egr, are there any negative implications to doing this.

On a seperate note my multiwagons suspension is really high at the rear and really low at the front, is this normal?

Many thanks for your advice so far, its been most helpful.

blank off the egr and take it for a spin, it sounds like the solonid is fubar, common fault and i think most jtd owners have had this problem at one time or another. the car feels like its gona stall under 2k reeves.
the mw does sit higher on the rear, this is normal as the car is designed to take bigger loads. both of our car cars are higher on the rear, and the jtd is lower on the front than the 1.6 (jtd is a heavier engine), you can lower the car easily enough but i personally need the extra clearance to allow me to fill her up when we go camping.

Thanks Roy for the info.

Just been messing with the car again and noticed a valve at the side of the turbo ( round metal thing, fastened with 2 bolts and a shaft coming out the top), what does this do? Am i right in thinking the shaft should move up and down as revs rise and fall? Mine doesn't. Are these prone to failure or is it more likely that the boost valve isn't sending a vacuum to it? Sorry for the poor technical knowledge.

The JTD engine uses a variable vane turbo. The "valve" you mention is a vacuum operated actuator that adjusts the vanes to increase or decrease the boost. The amount of vacuum applied to the actuator is controlled by the boost valve located under the left headlamp, or on the side of the battery box.

Thanks Davren, my actuator arm does not move when the car is revved up, which i pressume it should. Are the actuators prone to seizing up or is it more likely that its not getting a proper vaccuum from the boost valve?

I've had the car to my local fiat dealer for a diagnostic scan to try and get to the bottom of these problems. Apparantly the turbo has had it, technician said he was using his computer to call for maximum boost and was getting no boost at all. He stated that all the pipes were intact and that the boost valve and actuator were all working fine so it must be the turbo. Does this sound right?

ferritt said:

I've had the car to my local fiat dealer for a diagnostic scan to try and get to the bottom of these problems. Apparantly the turbo has had it, technician said he was using his computer to call for maximum boost and was getting no boost at all. He stated that all the pipes were intact and that the boost valve and actuator were all working fine so it must be the turbo. Does this sound right?

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Hey mate did u get this sorted? New turbo?

new boost valve fitted, freed of the rod that goes into the turbo to control the variable vanes, it did move but was very stiff, new genuine bosch maf fitted (2 new previous maf's from euro car parts lasted 2 weeks each ), all problems cured.

ferritt said:

new boost valve fitted, freed of the rod that goes into the turbo to control the variable vanes, it did move but was very stiff, new genuine bosch maf fitted (2 new previous maf's from euro car parts lasted 2 weeks each ), all problems cured.

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Did u change the MAP sensor too?

No mate, but i did take it out and cleaned it.

ferritt said:

No mate, but i did take it out and cleaned it.

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Ok thanks, did u have any maf error codes or just the p0236? Did u try unpluggin the maf at any point and if so was there any difference? Ill hopefully get a look at mine next weekend, dont wanna be buyin new bits that arnt gonna fix it! Thanks!

Just p0236 if i remember correctly, unplugging the maf helped and stopped the car from bogging down, plug the maf back in and it wouldn't rev up again

Just to update everyone on how i got on, only got looking at mine yesterday & today. Issues solved by the way.

Just to sum up my issues first, car was slow to rev up in low rev range - this was cured by blanking off EGR.

Had a problem also where car wouldnt rev past 3000 rpm; on a level road in 5th gear top speed was around 80mph with foot flat to floor, revs would only go to just below 3000 rpm. If you came to a hill and foot flat to floor still, car would slow down to around 70 or below, revs would drop to about 2500 rpm and just wouldnt go any higher.

If in a lower gear say 3rd or 4th if you held revs as high as they would go (approx 3000 rpm) then EML would come on and generate code P0236. Under normal driving though you could avoid this. Average MPG was around 45mpg, ill keep an eye and see if it now improves any - technically it should if black smoke is reduced etc.

So last night i removed the hose from the turbo to intercooler - was all covered in a thick oily grease. I cleaned it up and inspected it and couldnt identify any leaks. I covered the entire length in 2 layers of gaffa tape to test and refitted, power seemed to be improved, but still couldnt rev past 3000 rpm. I dont think the pipe was leaking but it may have leaked a little at either end or something.

I should note there was little difference with the MAF unplugged, it revved a little higher however there was little power near 3000+ rpm.

Anyway i removed the MAF to investigate and the cage/mesh ends of it had heaps of black stuff and bugs etc stuck to it. So i cleaned it all as best i could with electrical cleaner etc and refitted - problem now totally cured, revs on past 3000 rpm with ease and no hesitation and continues to pull right to red line. As i said before when i unplugged the MAF before it made little difference, but obviously even with default values it still wont let you rev too high with boost if it cant measure the airflow properly.

I was also experiencing a lot of black smoke and im fairly sure that is now significantly reduced as well.

Hope this helps someone else in their quest for power.