B18FT gurus please...

I have spent a whole day trying to get the fueling perfect on my engine, heres some spec-200sx t28, 15 psi, n/a cam, n/a throttle body, standard injectors, blanked icv and oil recirc,aem wideband.

Heres the problem, i struggled for ages trying to get the idle to high 14's i tried adjusting the idle and t/b bypass screw, the lowest i could get was 16, ive also turned the afm up to 650ohms, when normal driving its around 13.5 and WOT is 14.5:eek:, took it home and had a sit down to think whats wrong, after a while i decided to disconnect the tps of the bottom of the t/b and it immidiatley fuelled nicely at high 14's...success.

So ive left the tps connector off now and im wondering if any of you chaps would know if the tps fuels for the whole rev range or just idle, i havent had time to test it up the road now you see so basically im asking if i leave the tps disconnected will it fuel more on WOT also??

I just want to get it as spot on as i can for the day to scoffs:D

thanks chaps

Tim

Firstly for me i would be fitting some larger injectors in there, standards don;t fuel that much more past 14-15psi on a standard T2 so your really pushing the with a T28

if i remember correct, it is a on off type tps

It's mot really a proper tps just gives a shot of fuel when the butterfly is opened(when it clicks) you could try the TOS just past the click so it won't click when the throttle is opened. I just leave mine off tho.

You will defo need bigger injectors for that boost. I did use a rising rate reg for a bit and that allowed a little more boost with std injectors, but bigger is better:D

Ok fellas, thank you so much, so what injectors would you advise to use without having to make the afm bypass hole and also a decent psi?? i really want to see 200bhp or over on the rollers in a fortnight

thank you

Anything over standard you will Need some sort of bypass hole. rising rate reg will help richen it up a bit. Using standard injectors it should be easy to get it fueling well just sounds like they are past their limit. With a rising rate reg I had it fueling good at 20psi but on a t2/25.

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Originally Posted by SCHWARTZ

Anything over standard you will Need some sort of bypass hole. rising rate reg will help richen it up a bit. Using standard injectors it should be easy to get it fueling well just sounds like they are past their limit. With a rising rate reg I had it fueling good at 20psi but on a t2/25.

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oh, im sure i read somewhere that sieger ran saab reds without a bypass? i did have a fse fpr for my engine but i read bad reports about them saying they adjust themselves ect so i sold it to a volvo 480 member, what injectors are you running now schwartz?? psi and size bypass??

Probably something you have checked but just thought id point it out.... make sure theres no exhaust leaks.

firstly, has the ecu been modified? this is the main thing.
setting the afm to 650 is mainly done to increse the fuel coming on boost, adjusting it has more effect on idle as once it sees 5 volts it sees it as full. also as its a hotwire type temp can affect it too, on a couple of cars i've played with even opening the bonnet can make a difference.
the throttle switch has a 'click' in it, this activates the ecu to its base map settings. you could rotate the sensor just enough so it never clicks and try to adjust idle using the idle screw, tbh the idle control valve would help here. leaving it disconnect will work but you loose the 'accelerater pump effect' of the ecu as it only reads map/afm. at higher revs the ecu will see the afm at max, and with ecu mod it sees boost differently so it wont run as smooth but WOT isn't affected.
a rising rate reg helps for an increase in boost, but larger tb and cam affect the full rev range so you'd be forever playing with it.
without modifying with a bypass hole volvo 740 turbo green injectors with factory resistor pack will be the smoothest you can try, runs nice throughout the rev rang. boost limit varies between 18-21psi on different cars but should be enough to crack 200bhp. with your setup i recon 12/13psi is gonna be the max boost but you'll prob make 175bhp at that.

Yeh tone, ive checked the exhaust and all seems fine, haz ill reply to yours now mate, just trying to get my head round it,lol, just dont want to melt anything.

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Originally Posted by Haz

firstly, has the ecu been modified? this is the main thing.
setting the afm to 650 is mainly done to increse the fuel coming on boost, adjusting it has more effect on idle as once it sees 5 volts it sees it as full. also as its a hotwire type temp can affect it too, on a couple of cars i've played with even opening the bonnet can make a difference.
the throttle switch has a 'click' in it, this activates the ecu to its base map settings. you could rotate the sensor just enough so it never clicks and try to adjust idle using the idle screw, tbh the idle control valve would help here. leaving it disconnect will work but you loose the 'accelerater pump effect' of the ecu as it only reads map/afm. at higher revs the ecu will see the afm at max, and with ecu mod it sees boost differently so it wont run as smooth but WOT isn't affected.
a rising rate reg helps for an increase in boost, but larger tb and cam affect the full rev range so you'd be forever playing with it.
without modifying with a bypass hole volvo 740 turbo green injectors with factory resistor pack will be the smoothest you can try, runs nice throughout the rev rang. boost limit varies between 18-21psi on different cars but should be enough to crack 200bhp. with your setup i recon 12/13psi is gonna be the max boost but you'll prob make 175bhp at that.

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hello haz, the ecu has had the scoff mod and thats it, im going to try the 'never click' option with the tps sensor as the afr is spot on with the idle when it isnt 'clicked', i think my best option for now then is to buy a set of 740t injectors, i dont suppose you have the bosch number to hand for these Haz? also is it possible to buy the resistor pack online or does it have to be cut out of the loom?? also what do i set the afr to if i have to make a bypass hole??

many thanks for this help chaps, its greatly appreciated:agree:

scoff mod is the only option unless you go standalone really. what ecu is it?
try that and then adjust idle to suit. no need to be too fussy if your going to change injectors tho. think they've from the engine code b230f and end in 357? light greens. resistor pack is essential or it will blow the outputs of the ecu as impedience is different. resistor pack is part of the loom but you should be able to get both from a volvo specialist breakers. i forget whether they need to be wired in series or parallel but they're in pairs. scoff may know?
afr is afr whether there's a bypass hole or not. the hole is to trick the afm into thinking there is less air so puts less fuel in, but it will only go so low as still got to work in the parameters of the original ecu tables. if you mean afm, just whatever suits the car as each is different, but i've not needed a hole on these injectors on cars in the past

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Originally Posted by Haz

scoff mod is the only option unless you go standalone really. what ecu is it?
try that and then adjust idle to suit. no need to be too fussy if your going to change injectors tho. think they've from the engine code b230f and end in 357? light greens. resistor pack is essential or it will blow the outputs of the ecu as impedience is different. resistor pack is part of the loom but you should be able to get both from a volvo specialist breakers. i forget whether they need to be wired in series or parallel but they're in pairs. scoff may know?
afr is afr whether there's a bypass hole or not. the hole is to trick the afm into thinking there is less air so puts less fuel in, but it will only go so low as still got to work in the parameters of the original ecu tables. if you mean afm, just whatever suits the car as each is different, but i've not needed a hole on these injectors on cars in the past

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im unsure on the ecu atm haz but im sure its a burgandy colour, ill have a mess with the tps tomorrow and re[prt back:agree:,
ive been having a search on the net and im struggling to find any 740t's for breaking, im thinking of using saab reds (easily available to me) with the 32mm bypass now if that will work, it states that saab reds have an impedence of 12.0 ohm's so in your opinion will they be ok to use without resistors? have you any experience with the saab reds on this engine Haz??

thanks

Tim

saab reds are high impendance, so no resistors needed.

I didn't use red tops jet, only the 230 cc with no hole and a pres. reg gave me just al little more to play witch

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Originally Posted by REGGY5GT

oh, im sure i read somewhere that sieger ran saab reds without a bypass? i did have a fse fpr for my engine but i read bad reports about them saying they adjust themselves ect so i sold it to a volvo 480 member, what injectors are you running now schwartz?? psi and size bypass??

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I'm using Saab reds atm. Don't really know what size my bypass hole is as its loads of slits. At the mo my fueling is pretty good but I'm only running .8bar boost as a split exh mani and dodgy actuator have been causing all sorted now tho. WOT Was in the 10s afr earlier at .8bar so at the intended 1.5bar should be pretty good, il keep ya posted.

Ok then thank you for that,i think im going to try saab reds this weekend then,i would like to run 21psi,so can I drill a series of small holes rather than one big?also would I need to adjust to afm afterwards,im just a bit in the dark regarding the bypass hole and afm?

Series of small holes should be fine. You want to get it fueling nice at wot with the bypass hole, then adj the maf and idle screw etc....

Ok,cheers schwartz,ive got a better idea of what needs to be done now thanks,so basically when ive got the WOT as close as possible with the bypass I use the afm,t/b brass screw for fine adjustments on idle? After ive got WOT good with bypass then If i adjust the afm for idle will it affect the WOT?

No only the bypass hole that affects wot at that boost the afm reached the full 5v long ago.

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Originally Posted by SCHWARTZ

No only the bypass hole that affects wot at that boost the afm reached the full 5v long ago.

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Top man:agree: