I was having an issue of pegging my 05 ford slot maf in the 3 inch pipe . I plumbed in a 12 inch straight section of 4 inch pipe with the meter right in the middle, With 4-3 inch silicon reducers on each side. I took my old curve I, multiplied it by 1.86 to get a starting point.

The issue..

The car will start up and idle at 14.4afr on the wideband. If I rev it up at all it will go super lean and die. So I figure i need to change the kg/hr at the given voltages. So just to see what it would do I changed everything under 1 volt multiplied it by 1.1 nothing happened 1.2 nothing happened I even put in 100kg/hr at the bottom 5 cells and it doesn’t change a thing. When data logging its showing the corresponding changes I am making . so It will be showing .3v and 100+ hg/hr but its like it is not doing anything with the values it should kill the engine with that much fuel. What am I missing here? I only changed the pipe size.

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

make sure the idle maf voltage isn't below the minimum maf voltage scalar value else the computer will ignore the maf and throw up the failed maf curve

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http://www.efidynotuning.com/ford/

thank you, that is exactly what is going on.

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

anytime

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http://www.efidynotuning.com/ford/

to add to the subject, now that i switched to the 4 inch tube my signal is not as smooth. it fluctuates about .2-.4v think a screen is the solution?

also i don’t know what its about but i am also getting a random no start. when it isn’t starting im not getting any mafv. don’t know if its a maf issue or a eec issue or something else.

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

more info , noticed on the data logs when the mafv is 0 flags2 reads 0 when the maf has voltage it reads 32. also For_fuel reads 0 when it has no voltage and 1 when it does.

not sure if this helps any. i have no idea where to look. ive tried the wiggle test down at the computer and sensor and everywhere in between. when it works its just out of the blue. i had a datalog where it came and went over and over till the car died.

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

a screen wouldn't hurt but i doubt it will help

maf is ignored at crank so that shouldn't cause a no start

your witnessing the computer doing its job, thats exactly what its suppose to do



looking in your sig you have a blower listed, how is the bypass setup?

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http://www.efidynotuning.com/ford/

it is between the intercooler and the charger. plumbed to between the filter and the charger its a type r style. you think it has a relation to the no start?

why does the flags2 value of 32 go away when the mafv went to 0? this happend when the car was runing.

i put the screen in and it smoothed it out big time. this was just seeing how the screen worked i know the maf isnt close yet but you can see the car just died at about 59 sec is there anyway to use be and ea to help diag this issue?

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

You should have went to a 3.5" pipe or changed the electronics....I've never had good luck trying to use a 4"pipe with the factory electronics because of the lack of resolution.

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STLMustangs
Dealer and Tuning Support for DiabloSport,TwEECer, Moates, SCT & HPTuners

are you talking at idle? or driving? after i put the screen in, idle is great. havnt drivin it to much cause the car will just shut off then not restart.

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

if its dieing on decel it may be dropping to 0 volts and killing all fuel, set the lowest flow in the maf curve to the same as idle, may even need to up the min maf clip scalar, what does your inlet look like? i take it your maf is blow thru?

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http://www.efidynotuning.com/ford/

yes it is blow threw, it will die sitting there at a rock steady idle. the wont re-start it isnt getting spark and the mafv is showing 0 until it gets spark then then will show mafv when cranking.

im thinking the pip in the dissy. would that cause the computer not see a mafv during cranking? i just wana make sure im not trying to diag a computer issue.

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88 fox, 302, gt40 heads, intake, stock cam, long tubes, ati procharger 42lbs, 05 slot , infront of a viper t56

AL9, GUFB, QUARTERHOURSE. BE/EA

hmm interesting, a no spark isn't likely to be ecu related as the tfi still controls spark without the ecu (base timing)

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http://www.efidynotuning.com/ford/