Keir Gale

So I'm in the UK, and have a OBD1 B16a2 EG.
Decided it'd be a great idea to fit a set of ITB's purely for the clean look if anything, I've tucked and painted the bay aswel.
After a bit of research I went for CBR1000 Throttle Bodie thinking everything was basically plug and play.

Got them fitted a few day ago. At first using the CBR1000 TPS, which I had to 'create' a plug to fit. Turned the engine on and within a few seconds the CEL was flashing a code 7.
Literally made zero difference unplugging the TPS entirely.

Thinking about it, surely if I plugged my OEM b16 TPS in and just left it dangling, it'd be fine at idle.

Tried that, and it's doing the exact same thing, so I don't know if it's worth making a bracket to mount the B16 TPS where the CBR TPS is or not.

Any suggestions are more than welcome, in fact they are appreciated!

PyroProblem

3 wires go to the TPS.

5 volt reference
Ground
Signal

You want about .5 volt going to the ecu with the throttle closed (that's 0 throttle position)
You want about 4.5 volts at WOT (100 % throttle position).

Now all you need is a voltmeter. Good luck!

m4xwellmurd3r

What year are those itbs from? Mine are from an 06. I tested it and mines good, but since they use the k series style tps they tend to break really easily. Check resistance between pin 1-2 and do a throttle sweep to see if the resistance change is smooth, then do it with pins 2-3 (just to be safe) if its choppy, then the tps is dead.

BTW, the pinout between the b series and k series is the same (low voltage at idle, high voltage at wot) so make sure you didn't cross any wires.

whitesihatch

i have a set of cbr throttles laying around, may be able to salvage parts from it that you need.

IMO they are too small for a b16.

But like Pyro said all the ecu needs to know is tps voltage, closed and at WOT.

What tuning software are you using, are you utilizing a map sensor?

m4xwellmurd3r

The 1000rr itbs theoretically are large enough to support 200whp. The 1000rr are 44mm at the butterfly's. The 954rr however are 42mm. Jenvey states assuming 120mm from butterfly to valve, and max rpm of 9000rpm, 42mm throttles are good for up to 56hp per cylinder.

GhostAccord

Once you remove a TPS from the trottle body the voltage will be off. Even if you tried plugging it in to fool the ECU for idle the voltage will be off.

You need a volt meter and check what the CBR TPS is at closed throttle and wide open throttle. I am assuming that you are using a chipped/tunable EMS for such a build. Considering the stock ECU is run almost exclusively from speed density (MAP) algorithms. As soon as you go past 1/4 throttle you will probably loose all vacuum and the ECU will most likely not run well.

Now with most tunable EMS/chipped ECUs. You can take the Closed Throttle and Wide Open Throttle voltage readings that you got from the CBR TPS and add them into the software. Most times it is found under custom TPS voltage. You should also be able to do a cross over from speed density to Alpha N (TPS vs RPM). This will help smooth out the throttle.

You will still loose a lot of vacuum using straight ITBs. The use of a vacuum box usually helps keep brake booster vacuum. Along with any other sensors that you still have that will require constant vacuum.

Keir Gale

Thanks for all this help by the way, you just don't get this regarding ITB's on UK forums!

Right, what I've done now is bought a set of cbr954 ITB's because the TPS is plug and play bar swapping 2 wires around. They're on, it's running, no CEL codes at all.

It's heavily misfiring though, sounds like an impreza at idle and half throttle. Perfect at WOT.
I noticed it's as if 2 of the cylinders, so half the bodies are suckling in more air than the other 2.
It's as if they need balanced, presumably causing the misfire.

Anybody got any idea how to do this?

There's no adjustment screw, so i'm guessing it's to do with the metal rod on the injector side of the ITB's.

GhostAccord

Not sure about the 954 throttles but most 4 cylinder bike throttles do require synchronizing. You could probably have any bike mechanic come over with is carb synch tool and have them tuned up in a couple minutes.

It's basically a tool with 4 manometers (vacuum tubes half full of fluid). Once all 4 are hooded into the individual vacuum ports on the throttle. It will show you the difference in vacuum (air flow) between the 4 throttles. You can even these 4 tubes of fluid out using the idle air adjustment screws on the throttles. Once they are close to even they should all be flowing the same amount.

Some of the newer throttles have vacuum balancing/equalization ports between the throttles. And should not require synchronizing. That being said, if you do have a set with these ports, check for something plugged up in the ports. Dirt, oil, carbon, grease..etc...etc

PyroProblem

Make sure your MAP sensor has a good vacuum source and is not fluctuating too much at idle. Vacuum reservoirs usually solve this erratic vacuum by acting as a sort of buffer of the vacuum pulses.

Keir Gale

I've got a vacuum manifold for the MAP and the brake booster buddy.

I'll give a few local bits a call this afternoon, the difference between side is quite bad though, especially when the throttle is partly twisted.

I know the 2011 cbr1000 itb's I had certainly had that self sycronising thing however I'm pretty sure the 954 doesn't. It's from an older 03 bike. I'll try find a picture.

m4xwellmurd3r

Iirc (my 06 has em) there are mechanical iacvs for each throat. There's a lock but and screw for each one. I'm pretty sure there is also an adjustment for the plates themselves but I'll have to look. There is a manual you can download online for the 1000rr I found, and should be applicable to your itbs since the only differences are pretty minor

98vtec

what ems are you using?

Keir Gale

What do you mean by EMS?

Was up at the car last night again, let it warm up and idle. Sounds pretty bad, I've literally heard imprezas that sound less like an impreza.
Don't know if it's only running on 3 cylinders or what.
Running extremely rich though, and i'm presuming the smoke is unburnt fuel.

I've attached a video, if anybody could have a look at it, it'd be much appreciated.

https://youtu.be/_GxXARoulRo

GhostAccord

EMS =Engine Management System. In other words, are you running a tunable ECU or is it stock? A stock Honda ECU will have a real hard time running individual throttles.

Grey/white smoke like that is usually oil related or coolant being burned.

Black sooty smoke is usually an indicator of unburned fuels or rich air fuel mixtures.

The engine looks fairly new. Is this the first time running in a while?

Keir Gale

I'm running Crome with a basemap for a skunk2 inlet, aem intake etc etc buddy.

That's what I thought with the smoke, but the fact it's extremely rich, I thought that may be smoke related.

It is putting out some black smoke at WOT at high rpm, but just a puff, nothing major. I haven't had the cat a run yet though.

The engine was out for around a month bud, then refitted with the OEM inlet. And then I decided to go for ITB's. It ran perfectly with the OEM inlet though, so it's not something I've dome whilst fitting the engine I don't think.

m4xwellmurd3r

You absolutely cannot use a tune for a standard manifold on itbs. The nature of itbs means idle vacuum will be very low, and anything between idle and wot will be super rich (the car will think you're on the last few cells of the vacuum map) without some trickery involving check valves (which I'm unsure of its effectiveness till I do testing) you must use alpha-n if you want any hope of it running decently. Simply put, your car is running like *** because you don't have a tune for it.

It's like running a boosted setup on a stock map then wondering why your engine popped.

viperjng

Hi,

You need a proper tune prefably a dyno tune using a wideband and you'll be sorted out. Will be a lot faster and safer than waiting for answers here.

Jignesh