Mass Air conversion not working

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Mar 16, 2008 | 09:33 PM

milbags

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Mass Air conversion not working

Hey im new here and have a problem with a 89 f150.. i bought a used mass air conversion kit for my truck from ford racing and it seems that it will idle right but when you give it some gas i falls off the map and kinda studers and kinda smells rich and i was wondering do i have to change the firing order or is my computer gone bad or wiring somewhere.the kit came and i installed like i thought it should go with injectors 5678 starting from front to back on driverside and the 1234 starting from front to back on passenger side. and was told to cut off the map sensor vacuum tube .. someone please help

Mar 16, 2008 | 09:44 PM

EPNCSU2006

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From: Concord, NC

Did you disconnect the MAP sensor vacuum line?

Mar 16, 2008 | 10:05 PM

lmd91343

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From: Los Angeles, CA

Milbags,

Do you have an automatic or manual tranny? Is the kit for a manual or automatic? The part number on an A/T ends in "1". The M/T part number ends in "0". If you don't have the box, The part number is on the computer connector of the harness, by the pins.

The overlay harness has already been adjusted to convert to the truck 302 firing order.

What is the code on the computer box?

Are you sure that the intake hose from the MAF sensor to the throttle body is air tight?

The MAP vacuum line should be disconnected and PLUGGED. No need to cut anything. The MAP sensor should be exposed to the atmosphere.

I just went thru grief converting my '89 to MAF. It works perfect now. Hang in there!

Mar 17, 2008 | 08:42 PM

milbags

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Ya tried to play with it again to no luck. so i called ford racing and the guy wants me to time the truck to 8 degress and re gap the spark plugs to .30 and also set the idle on my bbk throttle bodie and check for codes on the computer and then we will see what the codes read and what not and see if it fixes it, what was your dalema when you installed yours

Mar 17, 2008 | 08:43 PM

milbags

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the computer is a a3m1 and the kit ends with 0 causes it's standard.. he said that it will work after this procedures .. it is running way to rich right now which i know it is

Mar 17, 2008 | 09:22 PM

lmd91343

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Joined: Nov 2007

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From: Los Angeles, CA

I had a couple of small problems: spark plug too hot; and fuel pressure too low.

Have you checked your fuel pressure? The diaphragm can rupture on the regulator drawing gas thru the vacuum line. Test it with the engine COLD!

Your computer is a early 90's M/T mustang computer which is right for the "0" kit.

How was the truck running before the conversion?

good luck,