Technical Constant fault with limp mode when first run 1.9 jtd 130 multijet

[jaydr]

Hi all

Im struggling with a fault with my grande punto sporting. Every morning when I set off on the daily school run, it seems to cut the turbo boost a bit then will go into a limp mode, where it refuses to rev beyond 3000 with no power at all.
Its also a bugger to start most of the time. It will randomly stop cranking and send the water temp gauge all the way up and throw up a overheating message. I've found if you let all the lights go out before you crank it, it will normally go.

I was told by its original owner that it required a new Maf so I got a bosch unit which seems to be working. When I check with multiecuscan it seems to be seeing 400mbar more air than expected at idle which turns into a fault. Its also complaining about the egr even though its still plugged In but I'm wondering if there's a wiring issue?

If you disconnect the battery for 20 mins, it will behave itself all day, which is a stopgap solution but id like to remedy it.

I must point out this car has a few mods done and has been dyno'd according to the previous owner who has inspected it and confirmed its all as it was when he had it.

The mods are a bigger hybrid turbo,and high flow injectors, decatted and dpf done as well,it has a straight through exhaust and the egr has been blanked off and a ramair cone filter has been fitted.

It made 232 bhp on the dyno but I can't verify as yet until I see the graphs but he says he's got them so I'll reserve judgment till I see them, but I will say its no slouch when it has warmed up.

Any thoughts at all would be greatly appreciated

Cheers
Jay

 

[g8rpi]

Apart from the usual suspects of the MAP sensor onthe inlet manifold or a dodgy battery negative lead, the number of modifications make it hard to say. And of course the modifications make the car illegal to use on the road.

Robert G8RPI.

 

[jaydr]

The map was throwing a fault but I've cleaned it and that one has gone away. I was wondering if a weak battery would maybe be a problem? I think it's not it very good shape but I'll charge it first and see if it helps. Is the negative lead a simple job on these? I've come from vag diesels so I'm not familiar with this lump.

Cheers
Jay

 

[jackwhoo]

The egr is blanked so if course the actual air flow is going to greater than expected because nothing is coming through the egr system.


Replacing the big thick battery negative cable should not be difficult , needs to be new from battery to engine/gearbox and from engine/gearbox to the body.

I hope it was cheap and has a long MOT test .

 

[jaydr]

So do they normally throw a fault when you do the egr delete on these? I had one on my bora and it never turned on the light.

The car is coming off the road shortly as I've got a new car coming, but I'm going to keep this for my son and when he turns 17 I'm going to use it to teach him to drive. So I've got 18 months to get it prepared for him so I plan on doing everything in that time.

Ideally I'd like to restore it to original power output. Once it's back to standard, I think its a cool little car for him to learn in.

Cheers
Jay

 

[levemircento]

it will probably be a fault with the pressure converter, assuming your turbo is a variable geometry type

it looks like this



follow the vac pipe from your tubo actuator back, it will go into this unit, then another small pipe will go the vacuum reserior on the back of the engine, and then to the vac pump.

if the valve is worn out, it wont allow vaccum to pull the actuator to move the vanes within the turbo, - no boost, so there will be no power at all [it can be intermittent]

you can buy original Pierburg ones off ebay for good prices, or you can even get cheap ones from places like aliexpress if you put in the original part number as a search.

 

[jaydr]

Ah this is the n75 Valve equivalent on a vw motor I think?

Ive checked it with multiecuscan and it seems to be functioning correctly.

Today I've managed to get a new air box for it. I have to say it's a marked improvement in performance.

All the strange turbo behaviour has seemed to stop, but I won't know till tomorrow morning if it has worked, but the numbers from MES are a bit better than before.

I also tried the egr solenoid test and it does nothing at all. The screen mentions a relay click and the egr is supposed to snap open and closed but nothing happens. I'm wondering if there is a relay somewhere I could change or perhaps a fuse?

Cheers
Jay