Jaycar Boost and Fuel Control

[sl33ek]

yeah and electronics hey, i hate troubleshooting problems. I'm sure its just one component thats misbehaving, thats all it takes

[benl1981]

Let me know what you find out I am more than happy to return it... I feel bad.

[Sydneykid]

My guess, in the "after tuning" A/F ratios the lean running at high rpm is nothing to do with the DFA. The sudden upwards flick is generally a sign of a failing fuel pump, fuel pressure regulator on the way out, blocked fuel filter or dirty injectors. I would have those potential issues eliminated before trying any further tuning.

The lumpy power graph is a dead give away for the standard ECU rich and retard mapping. So is the random black smoke (rich). R&R is triggered by AFM readings outside what the ECU expects, so any unexpected deviation from normal causes the ECU to adopt R&R mapping.

The 0.2 volts difference between input and output voltage is unacceptable, that is more than many of the correction factors you will input. It really needs to be trimmed out. If it is consistent (eg; always 0.2 volts higher at all input voltages) then it doesn't matter if you are tuning on the dyno, because the mapping will compensate for the input/output difference. It certainly matters if it is not consistent (eg; 4.6 volts in doesn't always = 4.8 volts out) or if you want to compare settings with others. Yours will always be several load points different to compensate for the 0.2 volts error.

If it is a consistent 0.2 volts out at all input voltages, my first check would be the resistor values. An incorrectly placed resistor will most certainly cause that sort of issue.

cheers

[benl1981]

All the resistor values should be correct I double checked with a multimeter all there values.

I did find with the calibration that when I had the multimeter on the input side as soon as I took the multimeter off it the load point would change by about 3 points. i.e. would go from 100 to 103 or something similar. I thought the multimeter was zapping some of the voltage as I was only using the silly trimpot that would fluctuate quite a bit

[illusiVe]

For the boost restricting thingie majig

is this basically what u need to do even tho i realise the 'tubing' is different lengths? (swaping the inner 'restricter')

also do Stagea's have a solenoid? (RB25DET from R34)

Edited December 6, 2005 by illusiVe

[Sydneykid]

For the boost restricting thingie majig

is this basically what u need to do even tho i realise the 'tubing' is different lengths? (swaping the inner 'restricter')

also do Stagea's have a solenoid? (RB25DET from R34)

<{POST_SNAPBACK}>

Yes, zakkery the same as R33GTST

cheers

[illusiVe]

another noob question.

IF i installed the EBC without any changes... are all settings programed to 0? if so that would mean the wastegate = COMPLETELY CLOSED (i think) = u dont want to hit boost.

so do i need to enter any settings before i kill my turbo being the noob i am

[Sydneykid]

another noob question.

IF i installed the EBC without any changes... are all settings programed to 0? if so that would mean the wastegate = COMPLETELY CLOSED (i think) = u dont want to hit boost.

so do i need to enter any settings before i kill my turbo being the noob i am

<{POST_SNAPBACK}>

Takes about 1 minute to change them all to 0. Then low boost, if any boost at all.

cheers

[illusiVe]

so when i install the IEBC that it will take the current settings i have, then i can adjust the curve from that, defult on the IEBC is NOT 'locking' the wastegate closed (god im stupid).. and i am soo buying that book... that'll learn me

[sl33ek]

Thanks SydneyKid, I was thinking there was a problem with one of those things too

I'm doing the fuel filter this weekend and cleaning out the injectors.

For testing the injectors is looking at injector duty cycle % enough to determine if it is faulty/clogged or not?

[Sydneykid]

Thanks SydneyKid, I was thinking there was a problem with one of those things too

I'm doing the fuel filter this weekend and cleaning out the injectors.

For testing the injectors is looking at injector duty cycle % enough to determine if it is faulty/clogged or not?

<{POST_SNAPBACK}>

Nope, injector duty is what the ECU is telling the injector, not what the injector is actually doing. Unfortunately it is an injector out, clean and flow test job.

cheers

[sl33ek]

I see. Ahh well I'll have to do that, its due for one anyway

[chrissso]

Hey All,

I went to the dyno yesterday and got my DFA tuned. It took an hour and a half. This is what we did,

-Adjusted the fuel trim.

Some one will have to explan this to me but he added in more fuel down low. I've seen this on SAFC graphs and I dont get why you increase the voltage at cruise levels.

Power run - low boost.

Suprisingly, my fuel ratios were 12.5\1 with out any adjustments. I put this dwn to a slight BIAS of about -0.03 volts at the top end.

-tuned the IEBC to about 11 PSI.

-High boost run

Now for the bad news.

He found that at high revs the ECU was pulling out a heap of timing - and getting up on the knock sensor.

Timing was found to be at base 20 deg. for some reason unbeknowst to me, so he pulled base back to 18.

Still had issues. Hooked up the fuel pressure guage and foung that PSI was dropping from 51 PSI to around 40 at high revs. Looks like the fuel pump is shagged. This will also account for the 12.5\1 fuel ratios that magically happened on the low boost runs.

SO, we actually added more fuel in at the top. I'll need to go back after the fuel pump is replaced to retune the top end.

The DFA seemed to work really well in what it was suppose to do.

A couple of extra things I found was that I hooked up a Ford EL o2 sensor half a week ago and the tuner said it wouldn't work as he had a 32 that came in with the same thing and it didn't work - however, when we plugged in the laptop and checked out the sensor reading it was working. AFR's on his sensor were good too. So there's one myth busted. Mind you, It's probably different between models. Mine's a Series 1 R33.

The other was the flames that were coming out the back on high boost. Looked good, but I've no idea if it was good or bad for the car!!

All in all, it was a fun day.. No hard reving for me though until the fuel pump is replaced.

Dyno graph is attached. He says his dyno read 10% lower than normal..

Looks to be about 170rwkws.

[Sydneykid]

Hey All,

I went to the dyno yesterday and got my DFA tuned.  It took an hour and a half. This is what we did,

-Adjusted the fuel trim.

Some one will have to explan this to me but he added in more fuel down low.  I've seen this on SAFC graphs and I dont get why you increase the voltage at cruise levels.

Power run - low boost.

Suprisingly, my fuel ratios were 12.5\1 with out any adjustments.  I put this dwn to a slight BIAS of about -0.03 volts at the top end.

-tuned the IEBC to about 11 PSI.

-High boost run

Now for the bad news.

He found that at high revs the ECU was pulling out a heap of timing - and getting up on the knock sensor.

Timing was found to be at base 20 deg. for some reason unbeknowst to me,  so he pulled base back to 18. 

Still had issues.  Hooked up the fuel pressure guage and foung that PSI was dropping from 51 PSI to around 40 at high revs.  Looks like the fuel pump is shagged.  This will also account for the 12.5\1 fuel ratios that magically happened on the low boost runs.

SO, we actually added more fuel in at the top.  I'll need to go back after the fuel pump is replaced to retune the top end.

The DFA seemed to work really well in what it was suppose to do.

A couple of extra things I found was that I hooked up a Ford EL o2 sensor half a week ago and the tuner said it wouldn't work as he had a 32 that came in with the same thing and it didn't work - however, when we plugged in the laptop and checked out the sensor reading it was working.  AFR's on his sensor were good too.  So there's one myth busted.  Mind you, It's probably different between models.  Mine's a Series 1 R33.

The other was the flames that were coming out the back on high boost.  Looked good, but I've no idea if it was good or bad for the car!!

All in all, it was a fun day..  No hard reving for me though until the fuel pump is replaced.

Dyno graph is attached.  He says his dyno read 10% lower than normal..

Looks to be about 170rwkws.

<{POST_SNAPBACK}>

That's a pretty nice ~25 rwhp gain from 3,000 rpm up to almost 6,000 rpm. Must feel much quicker right in the meat of the commonly used rpm range.

Yep, adding some fuel low down is very common. I think it is needed because of the usual efficiency improvements, larger exhaust, air filter, freer flowing cat and intercooler etc. But I reckon the main reason is, Nissan tunes them for minimum emmisions, hence lean as possible where it is safe (off boost). When you are going for the best power, emmissions is no longer a limiting factor.

cheers

Edited December 8, 2005 by Sydneykid

[chrissso]

That's a pretty nice ~25 rwhp gain from 3,000 rpm up to almost 6,000 rpm.  Must feel much quicker right in the meat of the commonly used rpm range.

Yep, adding some fuel low down is very common.  I think it is needed because of the usual efficiency improvements, larger exhaust, air filter, freer flowing cat and intercooler etc.  But I reckon the main reason is, Nissan tunes them for minimum emmisions, hence lean as possible where it is safe (off boost).  When you are going for the best power, emmissions is no longer a limiting factor.

cheers

<{POST_SNAPBACK}>

Yer, he had 2 dials on his software that he had to match. I think one was the ECUs target and the other was the calculation of the afr, and he said that because they didn't match, the ecu's fuel trim was adding fuel to compensate (?) (got no idea hey... ) Interesting though...

[Mr Void]

This is one informative thread!!

A big thank you to you Sydneykid - you have answered so many q's in heaps of depth!

Now for mine !!

If you could help me out here it would be appreciated. I am looking at using one of these IBC's but I am not applying this to a skyline - since however you (and so many others now) have such a great understanding of this device, along with the DFA, I am hoping you can help me out...

I am building a turbo 202 (yes it is a bl00dy holden!!) which has the old style k-jetronic (however you spell it) efi system on it, so the injectors all fire at the same time and it also just uses an air flow meter.

Do you think this IBC will still work ok since it is designed to sit on only one injector? From what I understand about the system I will be using the injectors will still fire at the same rate as any given injector in a multi point injection system so I am presuming it will work?

Any advice would be appreciated....

Void

[Sydneykid]

This is one informative thread!!

A big thank you to you Sydneykid - you have answered so many q's in heaps of depth!

Now for mine !!

If you could help me out here it would be appreciated.  I am looking at using one of these IBC's but I am not applying this to a skyline - since however you (and so many others now) have such a great understanding of this device, along with the DFA, I am hoping you can help me out...

I am building a turbo 202 (yes it is a bl00dy holden!!) which has the old style k-jetronic (however you spell it) efi system on it, so the injectors all fire at the same time and it also just uses an air flow meter.

Do you think this IBC will still work ok since it is designed to sit on only one injector?  From what I understand about the system I will be using the injectors will still fire at the same rate as any given injector in a multi point injection system so I am presuming it will work?

Any advice would be appreciated....

Void

<{POST_SNAPBACK}>

Oh my, a red motor, I owned one of those......once.......

The IEBC should work, it only needs a trigger signal that varies in length (gets longer) with engine load. Maybe stick a cro on it first, just to check what the injector signal looks like.

cheers

[Mr Void]

Oh my, a red motor, I owned one of those......once.......

The IEBC should work, it only needs a trigger signal that varies in length (gets longer) with engine load.  Maybe stick a cro on it first, just to check what the injector signal looks like.

cheers

<{POST_SNAPBACK}>

Cheers mate - thanks.

Oh and for your information it is a BLACK motor!!! not a snotty little red hehe..

[JD_R33]

Just a simple question about wiring the solenoid to the IEBC - does the IEBC ground the wire connected to the solenoid, in the same way as the ECU normally does to open it? Or does the solenoid need to be rewired so the IEBC operates it via a positive signal, rather than an earth?

[JD_R33]

Takes about 1 minute to change them all to 0.  Then low boost, if any boost at all.

cheers

<{POST_SNAPBACK}>

Isn't it the other way around? If all settings are at 0 the solenoid will stay closed, therefore the wastegate will see zero boost, therefore boost will hit maximum?

I would have thought all settings would need to be at 100%.......