Wideband tuners motorcraft 2150

WheelHorse · Aug 9, 2013

Stock 302, stock 2-1 exhaust with glasspack. 76K original miles.
2150 1.08 carb
Idle vac steady at 21

Timing total 32 under WOT: 12 base, 20 total mech. I was at 36 total, no adv and had some rattle, backed it back down to 32 total.

Vac mod timing 10...starts adding around 7" and is full 10 degrees by 15"

Vacuum while cruising 15-17 at 60-70 mph.

At 8" I can see the powervalve adding fuel on the wideband. She'll go from the 15-17AFR to 13's under 8" of vac. I would like to see 12's.

Idle...is steady at 14.5-9 AFR.

Slight tip in results in 19 AFR ?????
Highway is high 15 through low 17.
WOT...If I go WOT and hold it, she's at mid-high 13's...lean in my book
If I'm cruising and give a blip, the WB meter show's instantaneous high 12's and quickly leans back out, so accel pump works great.

If I lift to around 3/4 (going from WOT to 3/4) she momentarily go into the 12's but right back to mid 13's.

Carb was dipped for 48 hours, was in good over all shape. Through a Walker rebuild kit including power valve that came with it.

I have checked the fuel level with it running and away from the sides of the bowl, was dead on to whatever the spec had called for. I can look it up when I get home.

1) She was purchased in Texas and then lived in Denver. I'm wondering if stepping the jets up would bring the WOT to the 12's and the cruise to mid-14's. OR is this simply a power valve issue; needing a Holley PV to allow a bit more fuel in; if that's possible. Not sure on flow of either one. IF my feeble memory serves me well, I want to say the jets are 47-48.

2) The extremely lean 2-4% part throttle is concerning.

3) I will get the soapy water spray bottle out when I get home. My first step will be to verify if there are or are not any vac leaks.

First ride in this morning with the wideband, so I thought I'd throw this up to see if anyone else has come across this or has any constructive mentionables that may help a future member down the road.

Thanks for reading.

bmc69 · Aug 9, 2013

Hmmm.

8" is actually pretty "early" for the stock power valves to start adding measurable fuel. The only stiffer one I'm aware of is a 10.5" Hg Holley.

pcf_mark · Aug 9, 2013

People look at me like I am crazy when I say if they never tuned with a wide band they don't know $hit.

My tuning experience is 100% Holley and I tossed the Motorcraft and did not attempt to learn from it. Very simple but parts are not readily available.

Do you have ethanol added to your fuel in your area? In PA we have 10% ethanol at all times and this makes the afr need to be .5 richer to keep things right.

My $.02 from your notes:
1) Your idle is too lean. I usually end up at 12.5-13 afr at idle. This gives the smoothest idle and highest vacuum. This will help your lean condition at very small throttle openings also
2) I think you need more jet since your cruise afr is 15-17. Unless your spark is rock solid you may get lean misses at that afr. I like 14 - 14.5 15 max with todays fuel.
3) If your WOT comes back down to 12 with the jety change you are good. If not you can add more jet. But that makes the cruise rich just to get the WOT right. Take the power valve out and locate the passages that send fuel to the engine once the PV has opened. Open these up with a pin drill about .003 and you will see it on your O2. Go slow because closing these up once you open the is tricky!

Overall you are not too bad I bet it runs nice. Your advance curve seems normal but I think the factory vacuum can adds a lot of advance.

WheelHorse · Aug 9, 2013

Ya, I put a limiter on my factory advance arm and cranked the adj all the way to the least aggressive advance. Before I did this, the vac advance would come full 25 degrees advance by only 5-6" of vac. Add that on top of the 8 base (factory), plus the 25 mechanic confirmed by the light, it was too much.

I switched the boots (weights to the 10L) and confirmed 20 total mechanic, 12 base for a knock free 32 total. I plug the vac in for light load for only an additional 10.

PCF. I appreciate your advice.

Yes, Up To 10% E is in all gas, unless you go to marina and pay 50 cents more a gallon. This certainly could call for stepping up the jets. I do have a 1.21 carb off of a 351 I could put both jets in my 1.08, just to see if she'd richen up. Even if it's too much, at least I know it's a step in the right direction.

I also feel my idle screws are out further than I'd like them to be. I'm going to start with the vac leak (water in a spray bottle) test and see if anything comes up. Certainly, she could be leaking from underneath the manifold as well, but the vac idle being steady at 21 makes me think maybe not; only the test will tell.

I'm so used to dialing in fuelie cars with oh, well we'll just add 10% fuel here and global change to smooth it out and add/pull timing with a few key strokes and viola, you see results on the rollers.

I figured I would give the old Motorcraft a go with its annular boosters a different dist curve than the factory set up, hoping for perfection %)

You know, I even pulled the vac advance hose, plugged it for the last 5 miles of work with no change in AFR. I would have figured that if I pulled 10 degrees of timing, she should have richened up a point, but no change.

I'll keep on this and post back.

strokers · Aug 9, 2013

While I mostly tune air cooled engines vs liquid cooled I normally shoot for
Idle 13.2 to 14.2
Cruise 14.7
Full throttle 12.8 while some combos it won't keep steady do a average shooting for 12.8
All these will allow maximum timing for compression.

av bronco · Aug 9, 2013

For sure go bigger on the mains, good to see people using a w/b to tune.

jckkys · Aug 9, 2013

What year is your 302? In the middle of '72 production the cam timing was retarded 4 degrees. This had a big and negative effect on engine performance. The ignition timing is best tailored to the individual engine but I've found that Ford generally had too much centrifugal advance, not allowing enough initial advance. Original Ford vacuum advances can be adjusted independently.
The Ford carbs like Holley usually need a larger PVCR power valve channel restriction, as Mark pointed out. This keeps your cruse AF ratio lean enough while giving the enrichment needed for WOT.
Idle is best adjusted with highest vacuum. The AF reading doesn't account for intake distribution inequality.

broncnaz · Aug 9, 2013

X2 on the bigger mains. Power valve is fine. 8in is expected You actually dont want the power valve commng in until vacuum really drops due to extra load on the engine. I dont believe in opening up power valve restrictions aty least not on relatively stock vehicles. You can change the PV timing to get it to come in a little quicker but really its not needed.

Id try running a little more timing once you richen it up dont even worry about the vacuum advance unless your getting pinging. the vacuum advance is really only there to add timing when loads are low and with low loads you can use more than 32 degrees in most engines. Also when a t cruise RPM the vacuum advance may not even be giving you any advance. Probbably the reason you didnt see any changes with it unhooked.
As for your idle screws being to far out I really wouldnt worry about that as long as idle speed changes when they are turned then everything is good and I wouldnt expect a vacuum leak issue.
depends on what engine your carb came off of but it may have been on a EGR equipped engine and that could account for its lean setup.
Of course no matter what its still a carb and takes a lot of tuning to get all RPM ranges where you want them.

WheelHorse · Aug 10, 2013

Last night I got the spray bottle and distilled water out and went to town spraying all over the carb, lines, intake manifold several times where it meets each head and no change.

She did originally have an EGR and I've unplugged it. Diaphragm wouldn't pull in with a vac gauge. I also removed the source vac to the temp vac switch and capped it as well.

I started thinking back to exhaust leaks...there do no appear to be any, but it's also not computer controlled, so there's no computer to be out of whack.

Steps today are to check the fuel filter first! It has maybe a 1000 miles on it and with the plastic tank it should be clean but I don't want to assume.

If it proves to be well, I will pull the carb top and have a look at the mains to get numbers. I may swap in a rather large set off of a 351 1.21 set up just to see if it becomes a lot richer during cruise, or if it is all in the PV circuit.

Once I richen it up, I will go all back through the timing.

PS, I believe the highest vac method will still prove best idle over AFR, however, I don't want to be cruising down the road in the low 17's. Low 15's I'd be OK with for mpg purposes.

Broncnaz, in my first post I mentioned that I had tested the advance using a light and a vac gauge to see when and how fast and how much it came on. Anything over 5" of vacuum the vac adv canister was giving a full 25 advance. The curve was between 5-6, which means there wasn't a curve, it was off or on pretty much. Adding that on top of the 25 centrifugal by 3500, plus the base of 8....well you do the math. It's why I recurved the dizzy for 20 total, starts to advance by 1000 and ramps up nicely and by 28-3000 to a full 20. I didn't want to get too aggressive with the spring stretching seeing that the converter is so tight in the Bronco.

Broncobowsher · Aug 10, 2013

WheelHorse said:
Last night I got the spray bottle and distilled water out and went to town spraying all over the carb, lines, intake manifold several times where it meets each head and no change.

She did originally have an EGR and I've unplugged it. Diaphragm wouldn't pull in with a vac gauge. I also removed the source vac to the temp vac switch and capped it as well.

I started thinking back to exhaust leaks...there do no appear to be any, but it's also not computer controlled, so there's no computer to be out of whack.

Steps today are to check the fuel filter first! It has maybe a 1000 miles on it and with the plastic tank it should be clean but I don't want to assume.

If it proves to be well, I will pull the carb top and have a look at the mains to get numbers. I may swap in a rather large set off of a 351 1.21 set up just to see if it becomes a lot richer during cruise, or if it is all in the PV circuit.

Once I richen it up, I will go all back through the timing.

PS, I believe the highest vac method will still prove best idle over AFR, however, I don't want to be cruising down the road in the low 17's. Low 15's I'd be OK with for mpg purposes.

Broncnaz, in my first post I mentioned that I had tested the advance using a light and a vac gauge to see when and how fast and how much it came on. Anything over 5" of vacuum the vac adv canister was giving a full 25 advance. The curve was between 5-6, which means there wasn't a curve, it was off or on pretty much. Adding that on top of the 25 centrifugal by 3500, plus the base of 8....well you do the math. It's why I recurved the dizzy for 20 total, starts to advance by 1000 and ramps up nicely and by 28-3000 to a full 20. I didn't want to get too aggressive with the spring stretching seeing that the converter is so tight in the Bronco.

That's why you are lean at highway cruise. The EGR was there to add inert gas to the intake charge (it already burned once, not going to do anything the second time). This will effectively make a lean mixture a little richer. It actually helps gas mileage as it increases cylinder pressures at cruise without adding more oxygen and fuel. As a side effect the inert exhaust gasses also take out a little of the heat spike that creates NOx so it also helps with emissions.

I think the super lean tip in is opening the throttle before the idle transfer slots come into play. Drop a few degrees of initial timing, this will lower your idle speed. Crack open the throttle a touch (getting base idle closer to the transfer slots but not into them) and reset your idle mix. Now you should be able to tip in and get into the idle transfer without the hole. Or you have a bad idle transfer circuit.

broncnaz · Aug 10, 2013

The PV circuit haas nothing to do with cruise RPM. If your into the PV circuit when at cruise then your whole tune is out of wack or something in your setup is way off. of course you have good vacuum numbers at cruise so thats not the case.
Stepping up mains is your best bet all around.
Ive rarely had best luck running tuning the highest vacuum at idle. For me I seem to get better resluts with slightly lower than max idle vacuum. It usually helps raise the cruise vaccum for me when set a little lower than max.
Got you on the advance curve but the thing is when driving things are different during low load you can use more timing high load less. I dont factor in vacuum advance to total timing numbers as your engine can take more than 32-38 degrees of timng during low load. Of course you dont want pinging so backing off the vacuum is the best bet. Vaccum advance is really only there to take up the slack when the mechanical hasnt fully kicked in yet.

pcf_mark · Aug 10, 2013

I think your timing is good but other have some helpful comments. I would decide on a where you want it and not touch it until you are all doen carb tuning. Changing both you will get lost.

To be clear about the carb stages so you can tune w/o losing your mind:
Idle mix screws - impact idle to ~1,300 rpm
Main jet ~1,300 to redline at all vacuum settings
Power Valve any time the vacuum drops below the rating on the valve. This is usually when you floor it and the vacuum drops and is part of your total WOT number. The main jets PLUS the power valve restirctions make up your total WOT number.

If you make your WOT right usign main jets your cruise will be stupid rich. If you adjust the PV restrictions you can change the WOT w/o making the cruise rich.

bmc69 · Aug 10, 2013

pcf_mark said:
If you make your WOT right usign main jets your cruise will be stupid rich. If you adjust the PV restrictions you can change the WOT w/o making the cruise rich.

That..and one of the reasons that Holley makes both the "standard" and "High Flow" power valves. And then there the two-stage PV options to consider also.

WheelHorse · Aug 10, 2013

So here's what I found this morning:

I had a vacuum leak to the cruise control box...box itself wouldn't hold a vacuum on the source port. Plugged it and yet it made no difference...ugh.

Factory jets: 48 on both.

I installed a pair of 59's that I had from my 351 2bbl carb.

Cruising along is now 11.5 ish. So now I can add a blower LOL.

So the questions is, if 48's gave me a cruise AFR of 16-17 and if 59's give me a cruise AFR of 11.5 ish, anyone want to guess where the momma bear jet size would be?

Oh ya, I did the garage scientific method of leaning the idle out to 17 and then driving it and the cruise was still 11.5. I just had to check for my own research.

So what's everyone think? Order a 52 and 54 set?

Motorcraft Jets

pcf_mark · Aug 10, 2013

If you are an experimenting kind of guy and it sounds like you are...I would get the exact drill size of both jets and then find a drill (reamer would be best) that is in the middle. Then solder your 59 jet holes closed and carefully drill/ream to the new size. Then try that out. Somewhere you can probably find a jet to hole size orifice table for your jets so you could "make" a new jet the size you want. Then you can play around w/o buying a bunch of jets. I did this on Holleys because the jets are $15 a pair!

Either way you are going to need a jet on the rich side for when it gets cold if you hit dead on in the summer.

jckkys · Aug 10, 2013

The vacuum advance is not a take it or leave it deal. You can insert a 3/32" allen wrench into the vacuum nipple and turn it counter clockwise to increase the amount of vacuum needed to start the advance. Turn it 2 revolutions at a time till pre-ignition at part throttle is gone. The a mount of centrifugal advance is limited by the advance stop cut out on the bottom of the distributor sleeve ass. There 2 cut outs always use the short one. It will be stamped 13L,15L16L, etc. This is in distributor degrees or 1/2 crank degrees.
To properly set up a distributor get The Doctor's Step by Step Guide to Optimizing Your Ignition. It's the best book on curving a distributor.
Mr Gasket sells better centrifugal advance springs to improve the curve.
The amount of fuel added by the power valve is not restricted by by the PV on street cars.The PVCR is the metering device. In 2100-2150 carbs they are brass orifices pressed into the back of hole the PV screws into.
The main jets establish cruise AFR only. The WOT fuel flow is the sum of the main jets and PVCR. The choice power valve is all about opening point in inches of Hg vacuum. Any, will flow more than the power valve restriction in the carb. A cruise AFR of 15-16 is a good goal. WOT AFR of 12:1 is best for HP. To get there the PVCR needs to be opened up.
The fact that you have or had EGR means you also have the retarded crank sprocket. When you replace the water pump, install a roller timing chain with strait up timing. The improvement in performance will be noticeable.

Broncobowsher · Aug 10, 2013

Not all the vacuum advance cans are adjustable. Few stock and many replacement are. If the allen wrench in the nipple doesn't work, you have one of the non-adjustable ones.

broncnaz · Aug 10, 2013

Yes Id go with 52 or 54 jets. while you can drill jets its usually not recommended because the hole size is not the whole story on how it flows. I can see maybe doing this with motorcraft jets because they do cost a little more $10 a pair but holley jets are only $7 a pair. Here's a place that sells 2150 jets cheaper than your link. Could be other places as well its just one I have a link to. http://www.carburetion.com/ford2v.htm
While I dont disagree with the WOT tuning and PV mods few people run there broncos at WOT for any lenght of time so tuning for that is probably the least of your concerns. Not saying it shouldnt be done just saying Id keep the cruise RPM tuning as first and formost. Once thats correct your WOT will be closer to what it needs to be.

pcf_mark · Aug 10, 2013

I agree with broncnaz - if you can buy the right jets. I just do the solder/drill test to get close. I can be a cheap my wife says!

jckkys · Aug 10, 2013

If your cruise AFR is 16-17 with a 48 jet and the engine runs well, that's size you want. No reason to go to 52 or 54s. Cruise is where you do almost all your driving. If you want to try 50s , Walker Products sells them for $4.11ea. Broncnaz is right to point out that unless your a drag racer, or a any kind of racer the ideal WOT AFR is not important.
I just went through a pile of vacuum advance units and all are adjustable. The Ford units needed a 1/8" allen wrench. The Crane Cams units used the 3/32" size. I can't say much about Chinese types.
If you want to go further into your tuning, buy Holley Rebuilding & Modifying. All the principals of Holley tuning, apply to 2100,2150,or 4100 Ford carbs. Ignition timing is best covered in the Dr. Jacob's book I mentioned in an earlier post.

Wideband tuners motorcraft 2150

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