Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: hellsing73 on December 25, 2011, 07:59:19 PM

Title: map to maf
Post by: hellsing73 on December 25, 2011, 07:59:19 PM
I could not find any post about going from map to maf. Can any one tell me how or send me a link to a site that has it?
Title: map to maf
Post by: Haystack on December 26, 2011, 06:41:00 AM
http://www.coolcats.net/modifying/massair.html
Title: map to maf
Post by: hellsing73 on December 26, 2011, 08:09:06 AM
Thanks i forgot about coolcats
Title: map to maf
Post by: hellsing73 on December 26, 2011, 12:28:50 PM
Ok i got it all wired in but now i dont have any fule pre. Dose any one know why. I looked over all the pins and the all seam like they r locked in
Title: map to maf
Post by: Haystack on December 27, 2011, 06:05:17 AM
Are you getting power to the fuel pump relay? Good eec ground? Does the pump run when jumpered?
Title: map to maf
Post by: hellsing73 on December 27, 2011, 08:12:40 AM
I have not tryed any of that yet. Be for i took it a part it was working so i thought i messed something up in the convertion. Ill see if its geting power at all today if i can
Title: map to maf
Post by: hellsing73 on December 27, 2011, 09:55:14 AM
I found a diagram that tells me that im missing one thing that the coolcats info did not tell me. I need to add a wire from pin 19 to the fuel pump relay. That must be why its not starting. Oh and could some one let coolcats now that so no one els runs in to it too thanks. I have  the diagram and the page i found it on if any one wants to see it too. Thanks for the help haystack
Title: map to maf
Post by: thunderjet302 on December 27, 2011, 02:27:24 PM
You don't need to add a wire from pin 19. I didn't and it runs fine. I'd check for other issues.
Title: map to maf
Post by: Haystack on December 27, 2011, 09:36:24 PM
Yeah, that is just an optional fuel oump status monitoring wire or something like that. It will throw a code, ut not effect anything or turn on your check engine light. You have another issues. Try jumpering the fuel pump to run it, and check for power at your relay.
Title: map to maf
Post by: hellsing73 on December 28, 2011, 07:18:06 PM
I have power at the relay but and pump. If i jump the pump it will run but the key seams to not turn the pump on now?
Title: map to maf
Post by: Haystack on December 28, 2011, 08:37:28 PM
Check pins 20 40 and 60 for ground with the computer disconnected. The if the ground is bad to the computer, or the computer relay itself, then the fuel pump relay will not get tripped. So check all your ground pins and make sure you have good condituity, then check for power too and from the computer relay.
Title: map to maf
Post by: Haystack on December 28, 2011, 08:40:44 PM
I think it is going to be something stupid like a plug got disconnected, fried fuseable link by the battery tray, or maybe a grounding issue. Maybe eec relay.

Check the black grounding wire that goes from the battery to the fennderwell, then goes to a black plug to the injector harness. Make sure you have good ground between that wire and the computer.

The jumper for the pump just bypasses the relay. You basically need to find out why the relay isn't being tripped.
Title: map to maf
Post by: hellsing73 on December 28, 2011, 09:26:51 PM
It was working just befor i did the swap tho thats whats realing geting me stumped
Title: map to maf
Post by: Haystack on December 28, 2011, 09:33:51 PM
Well, go over the things you changed. There was a no start thread I started where tom renzo pointed out pins that could be burnt up on the computer. Have you seen that computer work in another car?
Title: map to maf
Post by: hellsing73 on December 28, 2011, 09:45:28 PM
Yes it do run. I drove the  car for a few
Title: map to maf
Post by: hellsing73 on December 28, 2011, 09:49:32 PM
The car will run if i jump the pump. I just cant find out where its messing up at
Title: map to maf
Post by: Haystack on December 29, 2011, 02:46:12 AM
Yeah, but it isn't tripping the pump. What codes are you getting? as soon as you get signal from certain sensors, it should trigger the fuel pump relay. So either your relay isn't working, or something else is wrong. Where it worked before the maf swap, I would guess something else.
Title: map to maf
Post by: TurboCoupe50 on December 29, 2011, 12:22:37 PM
The only thing that will prevent the EEC from cycling the pump when the ign sw is first switched on is a wiring issue, bad fuse link, relay, or the EEC pump driver in the 'puter is defective...

Throw the SD 'puter back in it and see what happens... If it still doesn't run, you Fu'd something up...
Title: map to maf
Post by: hellsing73 on December 29, 2011, 06:59:41 PM
Turbo the car will run only if i jump the pump realy
Title: map to maf
Post by: hellsing73 on December 29, 2011, 07:21:59 PM
Well from what i can tell the grounds are good and power too
Title: map to maf
Post by: Haystack on December 29, 2011, 07:35:20 PM
Either swap out your computer to the old sd one to see if it will trip the pump, or check along with your relay and wiring. Its possible you might have a burned up fuseable link, but I doubt it where the car runs when jumpered. Your sensors are wat tells the pump to continue running after its primed. But that is tripped by a pin in the computer to the relay. Your trip wire to the relay isn't working. See if its the computer, or wiring/relay by switching out the computer. If it works with the old sd computer, then its not wiring, and probably the new maf computer. If it doesn't work with the sd computer either, then its going to be a wiring or relay problem.
Title: map to maf
Post by: Haystack on December 29, 2011, 07:42:42 PM
I am guessing pin #22 fpr means fuel pump relay
http://oldfuelinjection.com/5.0Lpinouts.html

Check for power on pin 22, an at the trip wire to the relay and power through the relay. If you have power going through pin 22, then you can rule out the computer and check out the relay. You should also check your inertia saftey switch on the back panel by your drivers side light and make sure it isn't tripped.
Title: map to maf
Post by: hellsing73 on December 29, 2011, 07:51:39 PM
I looked at the inertia switch and it was not triped i also have power at the fuel pump relay. Ill look at the pin 22 and see if i have power their
Title: map to maf
Post by: Haystack on December 29, 2011, 10:33:30 PM
If you have power to the fuel pump relay, do you mean the relay is getting tripped? Or just getting power? Probe the wires after the relay. If your getting 12v after the relay, then the problem is inbetween the relay and pump. I doubt that though if the car runs jumpered at the sti connector.
Title: map to maf
Post by: TurboCoupe50 on December 29, 2011, 10:51:51 PM
If you have power at pin 22 that is the problem... Pin 22 provides ground, not voltage to the F/P relay...
Title: map to maf
Post by: Haystack on December 30, 2011, 03:51:59 AM
Sorry tom, I just re checked it. I pulled that up on my phone.
Title: map to maf
Post by: hellsing73 on February 18, 2012, 06:29:21 PM
i think its the ecm. if i jump the pump realy it will run but its surging realy bad and i have to start it like 5+ times to get it to stay runing
Title: map to maf
Post by: TOM Renzo on February 19, 2012, 09:42:59 AM
The Fuel pump relay (coil) is powered up by KEY BATT (from the EEC RELAY) and a ground from pin 22 Of the ECM. That Thunderbird i am assuming that is the car you are working on. Has an inertia switch that breaks the Battery to the FP relay winding not the pump feed. So to check the system turn ign on and ground the t-lg WIRE AT THE ALDL CONNECTOR. That will run the pump and test the system. If it runs the ECM is not supplying ground and to eliminate a wiring issue key the car and ground the pin 22 at the ECM. If the pump runs the ECM is KAPUT. Some guys leave the pin 22 permanently grounded when the ECM does this. But i dont recommend that for safety reasons. I always eliminate the INERTIA SWITCH because they are a pain. Hope this helps. Jumping the relay depending how you did it is not proof that the whole system is operating correctly. UNLESS YO DO IT AT PIN 22. Pin 19 is used for aux pump test (MONITORING) depending on the ECM you used.
Note the ECM does not supply a battery to the pump. It supplies ground to the pump relay.

Clearly you messed up a connection or the ECM is KAPUT. because the car ran previously. Good luck hope i helped.
Title: map to maf
Post by: TOM Renzo on February 19, 2012, 10:08:42 AM
Quote from: Haystack;376495
If you have power to the fuel pump relay, do you mean the relay is getting tripped? Or just getting power? Probe the wires after the relay. If your getting 12v after the relay, then the problem is inbetween the relay and pump. I doubt that though if the car runs jumpered at the sti connector.


Their is two battery supplies at the FP RELAY. Dont confuse the guy!!!!! Telling him to check this way is incorrect!!!

Once again car ran before MOD. ECM ISSUE OR WIRING. Iam going to say ECM because the pump wiring was not involved
Title: map to maf
Post by: TOM Renzo on February 19, 2012, 10:16:23 AM
Quote from: TurboCoupe50;376497
If you have power at pin 22 that is the problem... Pin 22 provides ground, not voltage to the F/P relay...


Tom after the ECM times  out (engine not running) depending on the type of test light you have the light will show battery through the relay coil. With the engine running it will provide a ground. That is why i dont use a circuit safe test light for circuits like this. They can make you chase BALLOONS. When chasing relay issues use a conventional test  light and from ground it will energize the relay if you are on the controll side that is looking for ground to operate. With a circuit safe (LED) test light it will show battery . Hope this is some help.
Title: map to maf
Post by: softtouch on February 19, 2012, 01:24:35 PM
Quote from: TOM Renzo;381087
I always eliminate the INERTIA SWITCH because they are a pain.

Tom, don't you think this may increase the risk of the fuel pump continuing to run after an accident?
If the EEC were to go into LOS mode it would keep the ground on pin 22.
Title: map to maf
Post by: TOM Renzo on February 19, 2012, 03:23:23 PM
I dont use them but if you feel better about it then use it. GM does not use it and neither does RANGE ROVER. They also dropped it. I cant think of any car company that uses the switch any more. Other than ford. If they designed a better switch i say ok. But they are a pain in the tail. I do agree they do work good in a crash. But they cause havoc in some cases.  I think most every car other than ford use  TIME OUT which is already built in to all FORDS with or without the switch. Just me and if you feel better with it by all means keep it. I just got tired of road calls with parking lot bumps rendering the cars a no start. By the way i do think it is a good thing if they get the switch to also not corrode and get intermittent opens. If the switch is in the high current feed it works better. But controlling the relay is a disaster, Not enough current going through the contacts to keep them from corroding. just me i am up in the air about this one.
Title: map to maf
Post by: softtouch on February 20, 2012, 12:50:31 AM
Quote from: TOM Renzo;381117
  I think most every car other than ford use  TIME OUT which is already built in to all FORDS with or without the switch.

You are right, it is usually just an extra level of safety. A healthy EEC IV will turn off the fuel pump if the engine stops running. That's why it only runs for two seconds when you turn the key on with out starting.

The EEC IV has a LOS (Limited Output Strategy) timer that the software must keep resetting before it times out.
If the software stops running for any reason the timer times out and the EEC hardware goes into LOS mode. This allows you to "limp" home with a broke EEC. This will keep the fuel pump running without the engine running.
In fact the pump running continuously instead of "priming" for a second with the key on is the test for being in LOS mode.
Title: map to maf
Post by: Beau on February 20, 2012, 02:08:36 AM
I knew of a younger guy, who was from the town my wife grew up in. Owned a 90-something F-150....he converted to carb, left the stock fuel lines, in tank pump, etc, bypassed the inertia switch or eliminated it.

He was headed home from his girlfriend's house late one night, fell asleep, ran off the road, hit a tree. Truck caught fire, fuel pump kept running. He was unconscious and the truck totally burned.

His girlfriend drove right past the smoking wreckage later that morning on her way to school, didn't even recognize it...


Would he have survived with that inertia switch in place? Who knows, but he would have had a better chance.

Sadly, this is a true story. My father took me to see the truck a few days later, and on the way asked me if my Sport had some kind of fuel shutoff in the event of a wreck. I said yes, and that it was a safety thing. He asked me if I planned to doi away with it, and I said no. Then he told me the details of the kid and his truck...





Leave the inertia switch in...if it's bad, there's more of 'em to replace with. You can never have enough fire protection on a Ford. I can personally say this...I've had 3 in flames. Luckily, very luckily, the only things damaged was fuel lines and a brake hose in, alternator wiring and connector in another, and the ignition switch burnt in an '89 F150. Thankfully, I had the column opened up, and it happened as I was driving. I was able to stop very quickly, pop the hood and unhook the hot battery cable, then smothered the small fire with a pair of leather gloves.

Again, if it ain't broke, don't remove it, and carry a fire extinguisher in every vehicle.
Title: map to maf
Post by: TOM Renzo on February 20, 2012, 06:33:00 AM
If memory serves me LOS must have a TACH SIGNAL. I will have to pull the strategies on this one. Not 100% on this it has been a long time???

Thunder the grown vickies and pinto owners would not agree. Between tanks cruse control and just about every switch in a ford the least of your troubles would be an inertia switch. But as you point out safety is the key. You can replace the switch with a RANGE ROVER unit that is 100% better than the ford unit. Or rewire the switch in the pump side of the circuit instead of the coil side. This seems to help but the Range Rover ones work better.
Title: map to maf
Post by: hellsing73 on March 01, 2012, 07:24:06 PM
well i think iv found out the problem is the ecu is bad. i was talking to my uncle about it and he said it sounds like a bad ecu. the ecu has a lot of white spots inside of it witch iv been told means water got in it.