map to maf

Topic: map to maf (Read 3452 times) previous topic - next topic

Reply #15 – 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

map to maf

Reply #16 – 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.

map to maf

Reply #17 – 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...

map to maf

Reply #18 – December 29, 2011, 06:59:41 PM

Turbo the car will run only if i jump the pump realy

map to maf

Reply #19 – December 29, 2011, 07:21:59 PM

Well from what i can tell the grounds are good and power too

map to maf

Reply #20 – 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.

map to maf

Reply #21 – 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.

map to maf

Reply #22 – 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

map to maf

Reply #23 – 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.

map to maf

Reply #24 – 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...

map to maf

Reply #25 – December 30, 2011, 03:51:59 AM

Sorry tom, I just re checked it. I pulled that up on my phone.

map to maf

Reply #26 – 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

map to maf

Reply #27 – 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.

map to maf

Reply #28 – 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

map to maf

Reply #29 – 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.