[Mk2] [Turbo] Overfuelling...Badly!!!

[Bea]

Hey guys,

i have a rev 3 turbo, .... mods: exhaust (Dep2), apexi air intake,... the car ran 265 bhp @fly,.... which was good,... but my dyno centre advised me to get a fuel regulator, as there was a little glitch on the dyno result, and apparently the car was running lean at first, then rich,.... but other then that , it was ok, held the boost nicely at 14 psi,....

so,... off i went and got a SARD fuel regulator, had it fitted,....( the same dyno centre's mechanic done it all wrong, hoses wrong way around, , wrong clips used, so i was losing fuel, dripping everywhere, pressure wasnt even adjusted ,... factory setting at 55 psi,... i did tell him to do it at 40 psi and 1:1 AF ration,... he obviously ignored that,... so nevertheless, i got it plugged in properly, fuel pressure set to 45 psi,... as he claimed that d be better then stock,... so done it but now my car is doing about 8 mpg OFF the boost , @ about 2k revs cruising!!!!,.... on boost ,..( which vary... 15-nearly 18 psi ) even half of that,.... i could easily go through the full tank in couple of hours !!!,....

apparently the place hasnt got a clue, what to do with that car,... took it back to have it sorted out, they done 20 dyno runs,.... poor car, car only done 1 bhp better than without the regulaotr, , 266 bhp... at 17.5 psi!!!... now that s just completely wrong there should ve been much better result at such boost,... plus all this overfuelling???....and power went down 20 bhp due to heat soak,.. and we got absolutely nowhere,...

error codes are not showing anything, ... everything is fine there,.... now obviously i will take the car somewhere else,.... but im thinking,... has anybody had similar probs after fitting fuel regulator???
Am i missing something here?... i expected a bit less mpg , but not this much,..... i will try to plug in the stock FR ( its still there, apparently when you fit a new one, it takes over the stock one, so it wasnt removed ..??..or should i removed it completely??)...see if that makes the difference,.... i dont think there is anything wrong with the Sard FR,....

please help,... any help will be much appreciated, and im sorry about a really long post

cheers guys,
B.

[screech205]

You sure he's put a 1:1 regulator on it? If it's a 1.7:1 then it will be ridiculously overfuelling!

With those mods i see no reason to go above stock fuel pressure as all you'll do is introduce even more fuel into an already rich mixture and get horrid MPG like you are doing.

I'd check that it's definitely a 1:1 regulator and take it somewhere who has a better knowledge of tuning tubbys than your man and get it set up properly.

Steve

[^Trickster^]

They do run very rich, afrs are common to be in the 10:1 kind of area, a picture of the afr graph would be helpful.

Are you on the stock ecu, if you are, put the stock fpr back on there.

And why would he recommend turning the fuel pressure up, thats only going to make it richer.

Graeme

[Driftlimits Performance]

hmmm, I'd take my car back first of all! 20 dyno runs and they extracted all of 1bhp

Like Trickster has said, can you get a graph up?

And still no error codes? Might be worth trying a few different sensors, o2 etc. gimme a shout if u need some.

[Bea]

this is the FR i have :

https://www.rhdjapan.com/home/products/ ... uct_id=568

and about the F/A ratio.... i kept telling him to make sure it was 1:1, but i dont think he had a clue how to get it right,.... although i remember form the dyno graph...A/F ratio said : 30:1...... i dont have these printouts though,.....

According to Amricans, it wouldnt make a difference whether you have FR at 40 psi or 45 psi....

Screech,.... i didnt even know there were that many different types of fuel regulator,.... one i got, is it right?..... it says you can use it instead of the stock one,..... do you need to get rid of the stock one, when you install that one?.... they told there was no need to take the stock one off, as the aftermarket one would take over FP .... is that right?

either way,.... i am not going back to that place, they re muppets,.... only done worse to the car,.... ...

i ll take the Sard one off , plug the stock one back in, and see whether MPG gets back to normal.....

here are the pics of the dyno runs BEFORE i got the FR....:

http://www.mr2oc.com/showthread.php?t=2 ... erfuelling


thanks guys for your help anyways

[screech205]

Running 2 FPRs? I'd be interested to see how that's plumbed in as most aftermarket FPrs bolt onto the end of the fuel rail where the old FPR used to live.

There's no info on that site about the spec of the regulator, does it not say anything in the box it came in?

Air/fuel ratio is different to the ratio of the fuel pressure regulator. The FPR ratio is how much the fuel pressure is increased when under boost, so a 1:1 ratio puts 1psi of extra fuel pressure per 1psi of boost. a 1.7:1 regulator would put 1.7 extra psi in for every 1 psi of boost which would make it silly rich.

Stock FPRs are pretty reliable as a rule and the little glitch could well be the fuel pump going from 9.5v to 12v when put under load.

Take your new regulator off mate and see how it goes. As stock ECUs aren't really mappable you might want to look into getting a piggy back ECU like a Unichip or something like a PowerFC which will allow a tuner to map the fuelling to your car. you certainly don't want something that's gonna put even more fuel in to the mix!

Steve

[Bea]

I dont have a box anymore ,so i cant tell you anymore info ....but here s the pic of engine bay,..... braided hoses are the fuel ones, one goes to fuel filter ...., the othe rone,... oops...behind the passanger side in th eengine bay, right by the fuel filter there is like a nipple thing there,...



apparently,... whenyou fit the new regulator , it takes over the stock one,...and if set up correctly, there wont be anymore pressure going in or more fule, the only difference you gain from doing this is apparently something like a more consistant fuel pressure and better delivery,.... i did not get the regulator because i wanted to get more fuel in, i know ,with my mods , i dont need it,...

[BenF]

Put the standard one back on, and ask for your money back

The MR2 (assuming fuel pump is OK) on a Standard ECU runs very, very rich on boost. So much so you can turn up the boost alone without worrying about adding fuel and still be running rich.