can't seem to control my a/f- runs lean

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floppy
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can't seem to control my a/f- runs lean

Post by floppy »

Newbie at the game I'm running msn-e, code o24s13, Megatune 225b717 on a 3.0 board.
I can't quite get a grip on controlling the a/f after checking and re-checking all of my settings
Even if I bump the reqfuel way up from the calculator or use the step function in ve in 10 step increments I can't make it run rich or rich enough.
It seems to stay in the lean condition up through the rpm
It's a 500 cubic inch cadillac running two holley 85# injectors
the pulsewidth is around 2.2 and the kpa is around 30
tried adjusting the fuel pressure to 25 # but didn't seem to care
seems like I'm probably missing something that's staring at me
been working at it for a couple of full days now searching and reading
Should could use a few pointers, Thanks

It was running on the Holley controller so even though I'm aware that it's a big engine, I know that it will run
snillet
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Post by snillet »

I´m curious about your settings, if you post your MSQ file more people will be able to help you.
Peugeot 309GR1990 XU9JAZ(4cyl 1.9litre) 10.8:1 CR with 60-2 VR wheel decoding ,V2.2 card, singel coil and dizzy spark ,360cc 0 280 150 431 injectors. Msns-E hi-res 10d2 and E85(Ethanol) in the gastank.
floppy
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Post by floppy »

Here is the msq file, Ibelieve that this is the currrent version , Thanks
snillet
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Post by snillet »

Doesn´t look too bad really, seriously.

Tried increasing the number of squirts per engine cycle to 8 instead of 4 ?, could be a solution, i´m not familiar with V8 engines or how they´re setup with TBI injectors in "dual" like yours are.

But i would have tried that.
Peugeot 309GR1990 XU9JAZ(4cyl 1.9litre) 10.8:1 CR with 60-2 VR wheel decoding ,V2.2 card, singel coil and dizzy spark ,360cc 0 280 150 431 injectors. Msns-E hi-res 10d2 and E85(Ethanol) in the gastank.
floppy
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Post by floppy »

It runs about thesame on 2,4 or8. I read somewhere that if your pulsewidth settings are correct that it should run on any of the permissable settings.

What I don't get is that I am not seeing a change in a/f even with a huge jump in the ve and reqfuel adjustments.

the one thing that I have not fully explored is the fuel pressure. I run supply and return gauges and with the holley the pressure had to be @ 27-28 which they say is the max for those injectors. But they are rated @85 # at 12 psi, although I have played with the req fuel numbers so that they are way higher maybe I'll calc the injectors at the highest pressure and use that inthe req fuel calculator.

So how do you directly influence the pulse width? can I reduce the time thresh-hold and increase the PWM % to get more fuel at idle or will that compromise my fueling capabilitiies in the higher rpm.

does the pulse width increase or decrease with rpm?

tHANKS
snillet
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Post by snillet »

I hope someone is more familiar with those injectors then i am...

All i know is that TBI injectors generally have a tendency to be a bit different from port injectors in the openingtime/workingpressure and all that.

For example on my car i have a injector that runs on 0.85bar(about the same in kg) and should inject something like 550cc/minute at that pressure. The Coil is a 1.6ohm and it´s NOT a peak´n hold injector..... instead it runs with a 5ohm(!) series resistor. That is not a common setup on port injectors :lol: ,and the opening time i´ve now gone down to 0.5ms but it seems ti be less then that to.

So you might want to explore what your injectors are meant to work with electrical wise to. So you don´t get screwed up in that area.

As i said, i´m not familiar with your setup but since there are lots of people from the states here yhere SHOULD be someone that is.
Peugeot 309GR1990 XU9JAZ(4cyl 1.9litre) 10.8:1 CR with 60-2 VR wheel decoding ,V2.2 card, singel coil and dizzy spark ,360cc 0 280 150 431 injectors. Msns-E hi-res 10d2 and E85(Ethanol) in the gastank.
floppy
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Post by floppy »

btt
AnthonyFury
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Post by AnthonyFury »

I think Snillet is onto something - maybe play with injector opening time? I have a feeling the big old TBI injectors are perhaps slower to act than newer Bosch stylees. I'm not a TBI expert, but I can tell you that changing the injector opening time on my friend's Mustang with a F.@.$.T. (we're not allowed to say that, are we?? :) ) from 1.0ms to 1.6ms made all the difference in the world. He was running 72# injectors on a 302, and the only way the car would run was by either tweaking the heck out of the tables or setting the engine displacement as 604" (exactly double).

BTW, I love the project! Got any pics??

Let us know how it goes.....
Anthony
tonybob.com
AnthonyFury
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P.S.

Post by AnthonyFury »

A quick (twisted) math check in my head brought me to this:

2x 85# injectors = 8x 21.25# injectors

If I had to bet, I'd say you're making more than 300HP (a properly running 500" Caddy should do that without even trying, right?). You might be on the edge or beyond the system's ability. I know you said it ran with the old system, but did you have an AFR gauge on it when it was running? Or does it feel vastly different while driving now (as compared to before)?
Anthony
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floppy
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Post by floppy »

More than 300 hp? Guess I forgot to mention the 060 over and the porting.

Yes, it did run before but when you see the project you will see why I don't need the top end.

Sounds like snillet maybe on to something with the injector opening time, I will check it out.

My current problem is that it starts and then dies soon afterward. It happened a couple of days ago, and then I was able to get past it but I don't know what the problem was and it is back.

Interesting about the req fuel why would it be double? But it is interesting because I set the VE table about 20 pts higher and it was still running lean.

Thanks for the help
floppy
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Post by floppy »

More than 300 hp? Guess I forgot to mention the 060 over and the porting.

Yes, it did run before but when you see the project you will see why I don't need the top end.

Sounds like snillet maybe on to something with the injector opening time, I will check it out.

My current problem is that it starts and then dies soon afterward. It happened a couple of days ago, and then I was able to get past it but I don't know what the problem was and it is back.

Interesting about the req fuel why would it be double? But it is interesting because I set the VE table about 20 pts higher and it was still running lean.

Thanks for the help
floppy
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Post by floppy »

here's a pic
floppy
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Post by floppy »

still not happening....

I love the project and the idea but I've spent a solid week trying to figure this one out... Pretty frustrated

I noticed in the tuning mode that goes through all of the setting that the afr for ve table one to be set for w/b but the constants page is n/b

why would the o2 always read lean, doesn't seem to matter much what the settings are

it does respond to the lean condition after 1300 rpm and it has always worked before as it did when I first started up ms

It seems as though it will read lean even when it seems to be rich. I then adjust it lean to be sure that it's not so rich that the sensor can't read

I am at my wits end hope someone has a direction for me, Mark
500 cubic inches, ms extra, 29v, 2.25,four 52# port injectors in an Auto-Nomics four barrel TB
floppy
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Post by floppy »

still not happening....

I love the project and the idea but I've spent a solid week trying to figure this one out... Pretty frustrated

I noticed in the tuning mode that goes through all of the setting that the afr for ve table one to be set for w/b but the constants page is n/b

why would the o2 always read lean, doesn't seem to matter much what the settings are

it does respond to the lean condition after 1300 rpm and it has always worked before as it did when I first started up ms

It seems as though it will read lean even when it seems to be rich. I then adjust it lean to be sure that it's not so rich that the sensor can't read

I am at my wits end hope someone has a direction for me, Mark
500 cubic inches, ms extra, 29v, 2.25,four 52# port injectors in an Auto-Nomics four barrel TB
keithmac
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Post by keithmac »

Have you pulled the plugs to verify that you are really running lean and it`s not a sensor fault? Take it you`re running a wideband AFR meter.
Squirted VW GTI 16vG60 mk2
floppy
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Post by floppy »

I'm runninng narrow and I 'll pull one right now
500 cubic inches, ms extra, 29v, 2.25,four 52# port injectors in an Auto-Nomics four barrel TB
dieselgeek
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Post by dieselgeek »

I had trouble getting the narrowband feedback to work at all this weekend. Same deal as you, even with a TBI and 60 lb injectors.


DIsable EGO correction and try doing this manually, see if it helps? What's your ego voltage showing in megatune when this happens?

also make sure your pulsewidths aren't trying to exceed 25.5 milliseconds - that's the max on megasquirt, even if it's below 100% duty cycle,

-scott
Squirted: it's easier to list the ones I haven't squirted. I need to do more motorcycle engines!
floppy
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Post by floppy »

I've definately had pulsewidth issues.

I just installed a wb o2 but haven't had time to play with it.

trying to finish the garage so the cruiser has a place to live...
500 cubic inches, ms extra, 29v, 2.25,four 52# port injectors in an Auto-Nomics four barrel TB
subie4me
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lean

Post by subie4me »

Put some bigger injectors in the thing.. I'm putting 6 65 lb injectors in a subaru ez30r. I'm looking for around 500 hp.
Turbo motors I've squirted. 4cyl subarus, 6 cyl subaru with vvt&vvl, honda3.5 with vtec, aircooled vw's, toyota v8, 2.5l autocraft, turbo intercooled yamaha rhino, more to follow
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