Well as some of you may or may not know I've been having problems with my 20vt and it's never felt anywhere near as fast as it should and bogging down a lot.

It has a full Stage 3 spec (Stage 3 hybrid, Pro alloy FMIC, SIP, organic clutch, 3.8bar fpr, mbc, walboro pump and wiring mod etc.) I had it dyno'd yesterday and the results were poor to say the least. It's been live mapped by a reputable tuner (Not Flea) on the forum but it only made 243.3bhp at 1.2 bar...that's 25bhp up on stock and it feels so flat to drive.



The fuelling is crazy rich and when we tried to up the boost to 1.35 bar (as it should be) the fuelling went all over the place and had a mad moment where it just leaned right out then came back. The power increased a little after the weird lean-out moment but still wasn't right so we put the boost back down to 1.2.



We performed a boost leak smoke test to check everything and there were no leaks to be seen which is a plus.

Can anyone shed any light on this, do you think the car has a fault or the map is bad? I'm wondering whether or not to chuck a GTEC2 in there to see if it improves it?

I cannot fathom what is happening with it, feels totally gutless on the road and with the spec surely it should be closer to 350bhp than 250bhp?

The car's only done 34k miles and most of the parts are, at most, 6 months old.

Appreciate all your help.

Speak to the tuner you took it to bud, they should be able to offer far more in-depth advice.

id avoid driving that with those graphs

so what was the outcome of the tuning session?

something is definitely not right there!

Frankly, I'd drive it gently down to Bristol to see Leighton

id take it to a mechanic to check out the engine first, no point in mapping if there are leaks, controller issues, sticking valves etc,

I think Flea can deal with that stuff, but yes of course, diagnosis and fix first

Have you spoken to the previous owner?

Classic signs of a maf issue assuming it was mapped right although there are various faults that can portray the same symptom.
The setup will never see 350 but should be late 280-300.

Boost and power are very delayed according to the graphs and its by no means smooth.

Been told by more than one person including flea that the setup is more than capable of 320-340bhp when setup properly with useable power.

This morning I was wondering if it was the MAF that's causing it to over-fuel.

Me and flea are in discussions too. It's very annoying as the car feels so so flat!

Also it does seem to have a real hard time starting too, so again, wonder if the MAF has gone bad. I can't see it on the bloody SIP.

Hi Marc,

I am guessing you sorted out your kangaroo boost running problems (coils/plugs?) from your previous thread in the technical area?

Dan

It wasn't the boost, it's all down to this fuelling issue.

Like others have said get it down to flea mate and let him sort the issues and map properly.

320bhp-340bhp is achievable with a stage 3 depending which hybrid turbo u have

Right I've just had my diagnostics gear plugged in and new information has come to light which makes sense

2 error codes found:

07 - Air flow meter (MAF) - Just as we thought
8A - Overboost strategy - Not sure what this is

So I'd say I need to get my hands on a new MAF and go from there? Best to get from FIAT or can I use a normal car parts distributor so long as I get a Bosch unit?

Probably cheaper to get from a distributor or a Bosch agent. Don't buy the after market ones. I tried one and it didn't work well at all.

What about a decent used one or is that a no-go aswell? Just seen the price of them

Ring CC or JBT, they'll see you right!

Check how old the maf error is. Its common to test it by disconnecting it to see how it runs and that gets logged as a fault. If someone has not already done that its worth trying to see what happens.

I'm no expert reading those graphs but the fuel ratio change is very sudden in the higher boost graph and coincides with maximum boost level. Given the fuel ratio is basically an O2 detector I wonder if you have a weak spark.

^ good call, dodgy coil packs or in fact a dying battery....

Battery is new, can't say the same for the coil packs. I'll clear the MAF error tomorrow and see if it comes straight back.

It's worth checking the wiring to the coil packs across the top of the rocker cover. The plastic deteriorates over years of heat cycling and cracks.

You seem to have a problem other than the mapping.

Taking your car to another mapper won't solve your problem unless you find out what is causing the issues.

Some mappers are better at mapping around problems than others, so if I were you, I'd try to sort the main issues out first.

As said I'm talking to Flea and trying to work out the issue. I'm sure it has something to do with the MAF or wiring but gotta take a closer look

Very strange that this topic has come up, I also have a fiat coupe 20vt, stage 3... Hybrid turbo. 1 bar actuator, FMIC, 3.8bar fpr, de-cat, 1.4 bar remap by flea....

This should have made 300+ BHP...
The car was on 2 rolling road dyno's
The highest figure it produced was 269.3 BHP and 260.1 Torque...


I still have not come across why my car is not making the 300bhp mark, as last year when it was on a dyno it made 303bhp, without the decat and was only running 1.3 bar.

Blue20vT, what dynos did it go on?

There can be many reasons why it didn't make the same power ånd we have been over this subject time and time again.

You cant compare different dynos due to there being different types, different conditions even when you using the same dyno there will be a difference unless it's the exact same condition to the last run you did ie intake temps, tyre pressures, gearbox and engine oil temps because colder oil will sap power especially the gearbox oil etc etc

I've just done a power run on a friends coupe at the heart breaker and it was down 27bhp and that was due to cold oils and odd tyre pressures which we then checked after the poor result and on the second run it was almost spot on figures to the dyno from about 3 years ago

We don't race dynos! I wanna see drag/lap times.

I had a de-cat added to the car and was running 1.3 bar, i took it to AMD at lakeside and it made 259.6. BHP and 256.5 Torque..

I then took the car to flea, had the map tweaked and boost was changed to 1.4 bar, i then took the car to Redline and it made 269.3 BHP and 260.1 Torque...

However the car still feels like it has made more than just 10BHP and 5 Torque...

Im happy with the car though, i know its quicker than that lol

Lap times Its more interesting

Ok so the story continues. I borrowed a MAF sensor from a friend's Coupe 20vt which runs perfectly and fitted it to mine but no change at all.

As you bring the car onto full load at 2800rpm it just starts juddering like mad then if you change down a gear with the revs higher it will pull but no where near like it should which is the same scenario as before. So it's still massively overfuelling for some reason.

I have noticed, tonight, that the lambda sensor looks as if it's been replaced with, possibly, a non-genuine item as the wires have been cut and rejoined under some electrical tape. (I assume this isn't right) So next bet is to change the lambda sensor with either a good used item or a brand new one.

If this doesn't solve it then I'm at a total loss as having spoken the person who mapped the car he said it was absolutely fine before so I'm starting to rule out mapping?

All help appreciated.