AFR check after new turbo

[RarlyL8]

Euro CIS would have the black iron fuel distributor and no Lambda.
You can tweak the WUR threshold settings on all but the earlier WURs. Go really slow with this as it is easier to reduce pressure than add it back when you get to the limit, you will be adding pressure on boost. The spec range I use is 11.5:1 AFR at boost onset to 12.2:1 AFR at 1.0bar boost redline. It takes some fiddling to dial it in as you are working with a see-saw where changes in one plane have some affect on others.
If using a mity-vac or air compressor you can control the pressure manually. Put a charger on the battery and run the pumps with the engine off and the WUR unplugged. Record system and cold control pressure. Plug the WUR in and observe the warm-up period until it is stable. Record warm control pressure. Introduce boost pressure slowly and record the threshold control pressure and the boost control pressure at 1.0bar. Raise the boost control pressure at the WUR slightly to the level you think it should be (based on where it is now in relation to AFRs). Drive the car and have a passenger read off AFR on boost. Repeat until the specs you want are dialed in.

[puddy]

Thanks Brian, so when you say " The spec range I use is 11.5:1 AFR at boost onset to 12.2:1 AFR at 1.0bar boost redline."

Since i'm running .9 bar boost, I should use same figures correct?

[RarlyL8]

That is the range I use, others may prefer a slightly different range. Yes I would use the same figures for 0.9bar boost.

[Alan L]

Those numbers are about where you need to be. Engine running clean, and still safe AFR.
I set idle mix by ear - not AFR. You will find a range of AFR that engines seem happy to idle at.
Do the WUR adjust first. Idle mix last. Depress the adjust screw, insert 3mm allen key and anti clock = lean, clockwise = rich. 1/4 turn is a decent size adjustment.
So you need to check warm WUR pressures first, then boost dump pressure (Mighty Vac). Don't hook a shop compressor direct to WUR - you will blow the diaphragm. gentle. Max WUR drop is around 0.3 bar boost pressure - you don't need to blow more than 0.5 bar. Warm pressure should drop no more than 0.5 bar. You may need to tweek your WUR warm pressure up by about 0.3-0.5 bar to get AFRs up to Brians levels.
Regards
Alan

[Alan L]

The Leask sw won't affect your AFRs at top end. It just delays when the fuel dump arrives. It 'evens' the fuel curve out a bit - so you can have decent AFR at top end without excessive fuel in mid range.
Alan

[puddy]

Originally Posted by Alan L

The Leask sw won't affect your AFRs at top end. It just delays when the fuel dump arrives. It 'evens' the fuel curve out a bit - so you can have decent AFR at top end without excessive fuel in mid range.
Alan

Thanks for the clarification on the Leask switch.

Also thanks for the info Alan & Brian, much appreciated. I received my CIS pressure testing kit today bought from fellow Canuck Phillip. I hope to get busy with it this weekend.

[RarlyL8]

Yes if using an air compressor get a feel for how well you can control the pressure before hooking to the gage and WUR. You will find that the fuel pressure on boost has a very short range of about 0.3bar threshold to 0.6bar max. I slowly take it to 1.0bar and record the range.

[puddy]

Brian, Do you mean if i'm using an air compressor as opposed to a Mityvac? I have access to a Mity vac so that's what i'll be using.

[1979-930]

^^^ Ditto. How would you use vacuum? I get the pressure to replicate boost.
I’m following along here too. I’m a week or two from needing to do this.


Sent from my iPhone while Driving

[puddy]

Originally Posted by 1979-930

^^^ Ditto. How would you use vacuum? I get the pressure to replicate boost.
I’m following along here too. I’m a week or two from needing to do this.


Sent from my iPhone while Driving

With the MityVac, I believe you can make it suck or blow, but Rawknees would know more about that than I.

[RarlyL8]

I've used both, the MityVac is easy to use and safer than the compressor which relies on a regulator for pressure control. Dialing down the compressor gives more precision. Either way cuts down on the number of road tests needed.
The 0.3bar to 0.6bar range I spoke of is the boost response range where the WUR will lower fuel control pressure. Warm control pressure is maintained until about 0.3bar of boost and then drops as the boost pressure raises to about 0.6bar. Above 0.6bar the decrease in fuel pressure significantly slows then stops. That is the range you have to work with and make adjustments to.

[Roby466]

Following this as well! Time to tune my WUR again as well!

[Alan L]

You get the WUR warmed up - takes 3-4 mins prob. You don't need to run the engine. pull the plug behind airplate. Turn key on and pumps should run and you will have voltage at WUR. Which will warm it up. Have your CIS gauge hooked in the system before you do this. Warning - you need to make sure you have good power going to the pumps - they suck a fair bit of juice and will pull a half decent battery down over this time. I hook jumper leads to an adjacent vehicle and have THAT engine running. Measure your warm WUR pressure (WP) - when it has stabilised. Pull the line that feeds in to the WUR from below the throttle body butterfly. This is the boost signal line. Either end - whatever is easier to get to. If you pull it at the WUR you need to hook another line from the mighty Vac to the WUR. The Mighty Vac works two ways - it has a slider valve on the end - suck/blow. Pull the valve back to the body (blow side). Hook on to warm WUR, and squeeze trigger a couple of times - you will see the gauge pressure rise to 0.5-1.0 bar. Don't go over 1.0. (damage daiphragm)
You will see the WP drop. Measure WP and the drop and report back. Then have a beer and wait for replies. Did mine y/day.
Alan

[Alan L]

Chris - have you checked your system for airleaks? Just a thought - without trawling back thru thread. Your symptoms are also typical of airleak in the intake system - lean idle AFR, rich boost. Any airleak will suck more air in at idle (vacuum) and loose metered air at boost - which the fuel system won't compensate for = rich. You need to be sure there are no leaks before tweeking the fuel system.
Alan

[Alan L]

Guys, while you are in there - you may as well measure Cold Pressure too (CP). This is the pressure you first register as soon as the pumps kick in. Note that, and the room temp at same time. That way we can relate whether is in spec too. The other pressure to note is the Rest or residual pressure . That is what is measured after you shut the pumps down. This tests the function of the fuel accumulator. it should hold decent over 30 mins or more. May as well collect all the data while on the job.
One more pressure - while in there - System Pressure. Pumps running, shut the CIS gauge valve off. Gauge should rocket up to around 100 psi. Note this reading too.
Alan

[puddy]

Great thanks again Alan, i'll check for air leaks. I don't believe there is any. It seems to run fine, and 3 out of 4 times it starts with a flick of the key, the 4th time I have to hold the key in start position and modulate gas and it finally starts. So maybe this weekend, I'll do my best to check for any air leaks. I'm not sure i'll get enough uninterrupted time to check pressures.

I have a battery charger with 3 charge settings, i'll use this while doing the tests.

[Alan L]

There are various ways to check for leaks - posted on this forum. I prefer to pressurise my system - from the rubber elbow after the airplate. Works great - no more than 5 psi.
Most people don't believe they have leaks - until they check. If you haven't done so, I would suggest this first. Otherwise your WUR tweeking may be premature.
Regards
Alan

[puddy]

Originally Posted by Alan L

Do the WUR adjust first. Idle mix last. Depress the adjust screw, insert 3mm allen key and anti clock = lean, clockwise = rich. 1/4 turn is a decent size adjustment.
So you need to check warm WUR pressures first, then boost dump pressure (Mighty Vac). Don't hook a shop compressor direct to WUR - you will blow the diaphragm. gentle. Max WUR drop is around 0.3 bar boost pressure - you don't need to blow more than 0.5 bar. Warm pressure should drop no more than 0.5 bar. You may need to tweek your WUR warm pressure up by about 0.3-0.5 bar to get AFRs up to Brians levels.
Regards
Alan

Didn't check for vacuum leaks yet, the weekend was too nice had other work to get done. I went for a rip yesterday afternoon and noticed the car pulled the best as the AFRs were 12, and the pull went away as the AFR's went into 11, 10, 9 territory. Tonight i'm going to spend a bunch of time on it. Check for leaks, then check Cold Pressure, then Warm, then Full throtle enrichment pressures.

Alan, where yo say "depress the adjust screw", I don't recall anything in the WUR instructions about pushing a screw to adjust it, I thought I just put the Allen key in and turn it?

Also my adjustable WUR I bought thru Brain @ Rarly L8 and he sent it roughly configured to my engine mods as I described to him. I believe there was some hand written specs on my instructions which I dug up recently. So i'm hoping I wont need major changes to get closer to what I need pressure wise.

[RarlyL8]

Specs are set according to the engine modifications so should be close. System pressure, boost pressure and idle mixture all play a part. The idle mixture screw is spring loaded, you must push it down (gently) to engage the receiver. Push down too far and the engine will stall. Adjustment should be CCW to rich first then CW to lean. Only a tiny adjustment should be needed if any at all. I would set the idle mixture first, if needed, then verify warm pressure before going on to boost pressure. Once all done recheck the idle mixture.

[Alan L]

Sounds hopeful if you have a pre adjusted Leask. But yes you need to be in the 12s. You can notice the difference. The idle mix is independant of the WUR - the spring loaded screw by the airplate.
Looking foward to the data. If you can get to 12 on boost now, prob more a small tweek and a boost dump correction/leask switch. Then .......wahoooo.
Alan