Engine tries to explode after M112

[volver]

lol. Yes i did get the 30 dollars gauge. A wideband O2 sensor measures AFR from 10:1 through 20:1. were as a normal O2 measures from around 12:1 through 16:1. Both cover the ideal range of 13:1 through 15:1. so during normal operation, the gauge i have should read fine. I have the gauge on 2 toggle switches. One that turns the gauge on and off. The other that switches between bank 1 and 2. If i decide to drive like a maniac, I switch on the gauge. When I floor it the gauge should max out a rich reading. I will know that i have an adequate AFR. iI the gauge starts to wander towards lean i can let off the gas. If at night and the gauge is annoying i can switch it off.

Later i can add a wideband gauge.


I will need a Wideband O2 sensor to tune the engine. This just plugs into the SCT X3.


I think the idle air valve was opening and closing. because if i taped the gas the engine would rev up then settle to 800rpm and 20 psi vacuum. It would then start bouncing again.

I have already constructed a new intake out of 3 inch mandril bent tube and 2 flanges. Looks like it will flow well. Only problem is that the air gets directed along the top of the bend and most of the air will be going into the left side of the supercharger. If it becomes a problem i will add a vane to redirect airflow or i will get the Lightning intake tube. I will post pictures once the truck is running. Last time i posted something half done i got my head ripped off.

I called James Henson. I purchased an X3. And an analog extension cable. I sent him a list of my mods. hes going to write a base tune. i will install base tune. engine should run well enough to trouble shoot any mechanical problems.

i also need to build an idler so i can still have AC.

 

[2000StreetRod]

Good plan & progress!

Some people are too quick to criticize while others are patient and helpful. That's just the way life is so don't let it bother you.

You have a plan that seems logical and James will provide you with a tune to make the vehicle at least driveable soon. From there it's just refinements that improve driveability and performance.

Most people have limited financial resources (especially these days) so it's not uncommon to progress in steps rather than all at once. This way you'll learn a lot more and have a greater feeling of accomplishment than if you just paid a shop to do everything for you.

 

[Mk3]

I just just wanna see pics of the finished project. Good luck getting it running. My buddy dropped in a F150 Lighting engine/supercharger/trans into his older F150 and it was a real pain to get it running right. Lots of work tracking down parts and fabbing stuff in the garage, not to mention time spent getting it to run right!

 

[lifted4.0]

my point with the AFR gauge is if you have a 30 dollar one and its not connected into the O2 sensor directly (not even sure if that is possible..) its just going to be a light show.. you need a O2 sensor directly feeding into your AFR gauge, cause the cheap ones are looking for a mathematical balance for the gauge, so its just gonna flip from lean to rich to lean, to rich stay at rich, go lean....i had a 40$ glow shift one, and thats exactly what it did, got an autometer wide band with the o2, best thing on my truck

you said "The other that switches between bank 1 and 2" so you might of done what i refered to, but me personally, i would still not trust that gauge

i also think with mine, when i was installing the stock idle air control valve...i had to mess around with the whole sizes on the gasket...cause if i port matched the gasket to the IAC, WAY to much air was getting in at idle..soo it would rev high

 

[CDW6212R]

FYI, the cheap O2 sensor gauge you mention and are using are not wide band O2's.

Those are useless for any indication of A/F ratios, throw it away. It cannot help for tuning ever, or to tell you what the A/F is, ever. They are not fast enough to use, only the wide band O2's are fast enough to be useful for tuning or for a gauge indicator.

I have one of those cheap gauges and slow O2's, an Edelbrock kit that cost about $125. I'd love to sell it for say $25, it's useless except as a light show. Who wants it, it's still new?

 

[volver]

There is no compute time, the gauge preforms no calculations. The O2 sensor produces a voltage based on the amount of oxygen in the exhaust. More oxygen gives more voltage.(maybe its the other way around.) As the voltage changes the lights change.

i don't know the response time of the none wideband O2. It could be slower then that of a Wideband O2.

If the response time is slower then there could be a problem if the AFR goes lean. I would not notice a change in the gauge before the engine melted.

The gauge will not be used for tuning.

I have confidence in the gauge. A friend has one installed on a carburated engine. He actually used it to tune the engine, after installing a new carburetor, enough to get the engine to operate correctly. After having a professional tune it with a wideband we could not notice a difference in performance. It did run smoother.

The gauge responds almost instantly when he floors it. it jumps to rich.

 

[lifted4.0]

ok, it was just my 2 cents

 

[wpurple]

I thought a narrow band just has two modes, 0V and 1.5V, it is the oscillations of that that determine the crude A/F? whereas the wideband gives a linear range?
might be wrong...

 

[XLRVIII]

Kiiiinda..
Actually the PCM is playing "for lack of a better term" PING PONG.

it enriches the fuel until it sees the o2 sensor switch, then it leans the mixture until it sees the 02 switch, then it just keeps going back and forth in this ping pong manner...

it's switching back and forth at or about 14.64 AF and it's measuring how much fuel it can dump before it switches rich, then sees if it pulls that amount plus a little more if the 02 doesnt switch back to lean.

the PCM is just playing with it'self/ 02's... nothing more, nothing less.

You definatley cant get ANY form of AF reading from a narrow band 02 sensor.

and those of you that think at WOT, just because the gauge stabilizes that is showing AF..it's NOT...

it's only showing you the commanded AF ratio in the PCM..
the AF the PCM is "shooting for"..which usually has little bearing on the "delivered AF" ratio

just because the PCM is shooting at .859 lambda doesnt mean the fuel system is delivering .859 lambda..

 

[XLRVIII]

But.. you can put a WB02 in place of your narrow band and have it Emulate a narrow band sensor.. which is very cool

Best of both worlds

 

[lifted4.0]

http://forum.e46fanatics.com/showthread.php?p=11187620

 

[CDW6212R]

...

it enriches the fuel until it sees the o2 sensor switch, then it leans the mixture until it sees the 02 switch, then it just keeps going back and forth in this ping pong manner...

..

Thanks for the details. I try to help, but I forget most of the details, the why or how. I learned this at least ten years ago, but new people still need to hear it.

It's good to see you drop in occasionally. Regards,

 

[volver]

The graph in lifted4.0's link explains a lot. I didn't know that the sensors measurement change was so abrupt.

Gauge should still work for what I want. The AFR goes above 14.7 the gauge should start to read lean. And I can lift off the throttle.

But I do see why it is useless. What reasons would the fuel mixture be lean. Fuel pump failure, a clogged fuel filter, a clogged injector, the fuel rail sprung a leak. If for some reason the fuel pump did fail while i was boosted the gauge would not save the engine from melting.
But nor would a wideband.

 

[CDW6212R]

The program inside your PCM is the real problem to begin with, that has been mentioned several times.

Your PCM is expecting injectors with half the capacity that you actually have. That program cannot ever control the fuel properly given those huge injectors compared to the OEM 19's.

Any change in the injector sizes requires a new program in the PCM. The old school electrical "tricks" used for EECIV cars are a waste of time and money given the capability of the OBDII PCM. With a simple change of the program, the OBDII can control those injectors. Get with James and he will put you close with the first program.

 

[volver]

I called James Henson. I purchased an X3. And an analog extension cable. I sent him a list of my mods. hes going to write a base tune. i will install base tune. engine should run well enough to trouble shoot any mechanical problems.

 

[volver]

Tuner and Lightning MAF came in today.

I was expecting there to be an option to change fuel injector size. But there wasn't. I don't know if the SCT sight was lying or if the option is only available to certain cars.

I checked every menu (even the illogical ones)

I will try to update the device

Does anyone know if the SCT X3 will give me the option to change fuel injector size?

 

[JDraper]

The X-Cal 3 doesn't have the built in capability to change the fuel information, but the tune you get from James that the X-Cal downloads into your truck will. The X-Cal is the device for doing the download, you need to have someone write a tune for you, and then you download it into your X-Cal from a pc, and then load it into the vehicle.

 

[2000StreetRod]

Options enabled later

I believe the way James controls the number of variables to avoid unneccesary complications is to provide a blank X3. He will probably enable the user options when the tune is complete. However, you'll probably be so satisfied with the tune that you'll never change what he has provided.

 

[CDW6212R]

Ditto, it's all in the program. The program controls the fuel based on total volume, not injector sizes. James is an experienced programmer, he makes the PCM work with the injectors you specified. After that and a little fine tuning with wideband O2's and data logging, it may run as smooth as most stock engines.

These OBDII PCM's are not like old EECIV junk. With EECIV you have little control over it, the aftermarket made tons of stuff to "trick" the existing PCM program. That's where you got the mentality of FMU's, calibrated MAF's, MAF tweakers, MSD boost retard boxes, etc, etc. All of that garbage is unnecessary with OBDII. With OBDII the program controls everything, without those gimmick devices.

You will be pleased once you get the new programming and get if fine tuned. Be patient.

 

[volver]

I was looking for an adjustment for the fuel injectors so i could move the truck back home.

I looked around, turns out the fuel injector size option is not available for the explorer. But say you have a mustang cobra you can change the injectors to a different size even chose the size of the blower you just swapped over.

I guess that SCT figured that the only mods an explorer would get are an intake and an exhaust and some 93 octane.

so i will have to wait for a base tune before i can move it home.