mass air conversion problem!?!?

[beaver2489]

Ok, I ran the MAF wiring through the firewall and hooked everything up. and my fuel pump won't come on...? If the computer I got with my mass air stuff isn't really a mass air computer will it make the fuel pump not work? The computer my buddy gave me has this on it EEC IV --> E7SF-12A50-E1A . Is this a mass air computer? The computer that came out of my 88gt vert 5speed has this on it EEC IV -->E7SF-12A50-Z1B they both look like speed density computers to me... under where it says EEC IV it says SFI-SD1. SD1 meaning speed density right??? which means I got the wrong computer?

 

[RacEoHolic330]

You need an A9L computer. You also need to cut a wire from to computer and splice it into the fuel pump relay under the seat if you didn't already.

 

[beaver2489]

I found out it is the right computer, it's just in a older casing... no I haven't spliced any wires. If I have the WHOLE wiring harness out of a mass air car and the computer, why do I have to splice wires?

 

[dvs bullet]

the whole harness is out of a mass car?

 

[fivepointohgt]

I found out it is the right computer, it's just in a older casing... no I haven't spliced any wires. If I have the WHOLE wiring harness out of a mass air car and the computer, why do I have to splice wires?

The old casing thing doesn't make sense to me? Are you saying that someone removed the casing from a SD computer and put it on a mass air one?
The only way that 88 GT had mass air is if either it was orginally from CA or there was a conversion. Also, SD computers started with "E-SF" and the mass air ones were "E9ZF". Sorry, but it looks like you have a SD computer on your hands. Replace it with "E9ZF 12A650 AA" with the A9L code.

 

[beaver2489]

the casing of the mass air computer got damaged. So he took the computer 'guts' out and put them into a spare SD computer's casing. He had it in a mass air mustang and it works fine. and the wiring harness is out of a mass air car. I tried hooking my SD computer up just to see if I could get the fuel pump to prime...no fuel pump action. What wire am I supposed to splice to the relay under the driver's seat?? I'm going through the wire harness right now and making sure theres no stripped wires and I see no bare wires. On my wire harness ( from firewall-inside car in kickpanel)...the cluster that hooks to computer, a green connector, a ground, a big block fuse thing, and a grey circular connector. The grey connector I can't find a use for. If I can get my camera to work with my computer I could show pictures that would greatly help me in describing what I have going on. Thanks guys

 

[dvs bullet]

Stupid question, did you check the fuses, and the saftey shut off? Also again, are you a full harness from a mass air car or an adapter?

 

[beaver2489]

ya I've checked the enertia switch and fuses. its the whole harness. We took it off a mass air mustang. its not just the wire connector to the mass air meter, its the whole wire harness.

 

[dvs bullet]

Check to see if you have power to the fuel relay under the seat, then you cansee which direction to go.

 

[beaver2489]

ok, I took out the mass air wiring harness and put the SD wiring back in. I hooked it to the mass air computer even, so I know my problem wasnt the computer cause the fuel pump primes now. If the mass air wiring harness I have it off a newer stang (93+) is there some wires I need to change to make it work with my 88? Also can I get the #24injectors to work with my speed density? remember I have the Crane Interceptor PMS...

 

[jrichker]

Copied From bbunt302

Just for reference, here's a list of all the compatible years:

89 harness should work for 86-89 as long as you're using mass air.
90 harness will only work in a 90. (B/c of air bags and dual dash connectors)
91 through early 92 harnesses should be compatible (single dash connector, fuel pump relay under driver's seat)
Late 92 through 93 harnesses should be compatible (single dash connector, fuel pump relay under the hood)

Did you install a relay in the fuel pump relay socket that mounts under the MAF? That's the relay that works the fuel pump now , not the one under the driver's seat.

 

[beaver2489]

ok, heres a pic of the mass air connector and the 2 big plug/relay things...are one of these the fuel relay?

and heres the speed density one, theres only one big plug/relay thing by the airbox

 

[beaver2489]

If one of those in the first picture is the fuel pump relay, then I should do away with one thats under the seat? edit: Ok, I did some searching on FP relays and the 2 in the first picture are FP relay and WOT relay, and the second pic with is the 1988 SD wiring is just the WOT relay....this sound right? so I'm gonna put the mass air harness back through the firewall and hook it all up. undo the relay under the driver seat and see if the pump primes, then try switching the FP and WOT relays to see if maybe the FP relay is bad...I guess we'll see what happens

 

[jrichker]

The relay under the seat is not functional when you use the 93 Mass Air harness. It uses the Fuel Pump Relay near the airbox

For help on the 93 harness, see http://www.autozone.com/images/cds/gif/large/0900823d80195960.gif

The relay in your second photo is the A/C WOT relay that shuts off the A/C at Wide Open Throttle.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for the 88-90 wiring harness

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

 

[beaver2489]

thanks man, I'll see if maybe the fuelpump relay is blown on the mass air wiring harness

 

[beaver2489]

I swapped the WOT and FP relays and still nothing......

 

[jrichker]

Check for 12 volts on the pink/black wire of the fuel pump relay. No 12 volts, bad fuse link, bad connection or bad wire.

No 12 volts on the red wire the ECC power relay isn't working, or the fuse link that feeds the ECC relay is bad.

Good 12 volts on both the above, look for 12 volts on the Dark green/yellow wire. No 12 volts, find the ECC self test connector over by the power brake booster next to the wheel well. Then jumper the Lt. Blue/Orange wire to ground. No 12 volts on the Dark green/yellow wire, the relay is bad.

Good 12 volts on the Dark green/yellow wire, check the inertia switch. The inertia switch is on the driver’s side by the taillight bulb wiring. You should have 12 volts on both sides when measured to ground. If you have 12 volts to only one side, the inertia switch is open. Press to reset the inertia switch.

Good 12 volts on the Dark green/yellow wire, 12 volts on both sides of the inertia switch, the pump has failed, has bad wiring, or missing ground.

If you got this far with the pump test (the Lt. Blue/Orange) wire jumpered to ground and the pump runs OK, the computer has an internal problem.

 

[beaver2489]

I turn the key on and I get no voltage anywhere... 0v at inertia, 0v at FP relay...all through the whole fuel pump circuit, nothing. So I think I have a bad fusable link somewhere. I'm just gonna put the SD wire harness back in and run it with the #24 injectors with SD till I get the wire harness fixed, or I just might save up for a carb, intake, and msd go that route. Then sell all my new EFI stuff. I have a Crane Interceptor PMS that allows me to adjust the injector pulse percentages...so I'll see what I can do with it. I know I can get enough out of all my EFI stuff to get a carb setup going. I should have went carbed in the first place lol THank you very much. You helped me narrow down my problem point.