New stuff - start then no start - code 96 - help - jrichker?

Hi-Po

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Mar 31, 2005
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Oslo, Norway
Sorry bit long but please read - need help with a start problem:


I have finally completet the installation of the following new parts:

Trick Flow heads and roller rockers pushrod lifters
Summit MAF calibrated for 30 lbs injectors
Trick Flow 30 lbs injectors
Edelbrock 70 mm TB and EGR plate
Aeromotive adjustable fuel pressure regulator

Otherwise the car is as per signature and/or original/stock.

Upon finishing all the installation work today the car started up nicely, but the fuel pressure was way too high reading about 60 psi on my in-car gauge.

After a couple more start ups and adjusting the FP down to around 48 psi no vacuum / 42 psi vacuum attached then the car suddenly wouldnt start.

It has spark on the plugs and cranks over but no start. Plugs appear dry.

The fuel pump doesnt sound good at all, but the pump seems to work somehow as the fuel pressure rises immediately when turning on the ignition.

I did increase the fuel pressure back to 60 psi since the car started initially at this pressure, but no surprise this didnt help.

Then I scanned the codes and got two: Code 67 which I have had for a long time and I am pretty sure this has nothing to do with not starting now - and also Code 96 in the continous memory.

Code 96 reads: "High speed fuel pump relay circuit open, Fuel pump secondary circuit failure"

I understand the words, but not really what it means...

Anyhow, it seems obvious that it is fuel/fuel pump related - but what puzzles me is that I get a solid high fuel pressure when igntion on??? I would imagine I should have no fuel pressure if the pump or pump relay didnt work?

The fuel pressure drops to about zero on the gauge when cranking the engine.

I have a brand new Trick Flow 190 lph fuel pump which I havent installed yet - but what do you people think?

Does anyone have experience with code 96?
Where is the fuel pump relay located, and what does the error message really means...?

Sake order the fuel pump I have in the car right now is the original one, and total mileage is about 90,000 miles.

Help/advice/input greatly appreciated!
 
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Well as for the location of the Fuel Pump Relay, depending on the year, will be either under the drivers side seat, as like mine(87'), or under the hoses for the mass air meter on the inner fender well.

Test that to make sure the circuit works, I do not recommend jumpering the wires and bypassing the relay. Though it may work to test. If the relay tests good on both circuits then there is no need obviously.

If that doesn't make the pump whine and sustain pressure while cranking then it may be safe to say your pump burned out. Unlikely but possible.
 
Well as for the location of the Fuel Pump Relay, depending on the year, will be either under the drivers side seat, as like mine(87'), or under the hoses for the mass air meter on the inner fender well.

Test that to make sure the circuit works, I do not recommend jumpering the wires and bypassing the relay. Though it may work to test. If the relay tests good on both circuits then there is no need obviously.

If that doesn't make the pump whine and sustain pressure while cranking then it may be safe to say your pump burned out. Unlikely but possible.

Thanks TenorPlayinGuy.

I feel pretty retarded when it comes to auto electrics, and I dont have my car here.
What does the Fuel Pump Relay looks like? I think the only electrical stuff under my seat is the seat belt warning and lumbar adjuster..
Guess I will find it tomorrow on the inner fender well.

Could you please explain how to test the relay, using a voltmeter I suppose, but how?

I am still puzzled why I have fuel pressure apparently (according to the gauge) but no fuel to the injectors.

Would I get this code 96 if the fuel pump itself has burned out?

Cheers..
 
If you think your injectors are not firing, check a given one for constant accessory 12V (key on). Use a noid light to see if they are receiving a ground pulse while cranking.

If not, check that the TPS isn't reading above 1.5V at idle.

Then do a continuity test on the individial injector driver wires (between the injectors and EEC).

JRichker's Cranks But No-Start list (in the Useful Tech Sticky) will be very helpful while you diagonse the issue.

Good luck.
 
Code 96 causes & tests 91-93 models. – KOEO- Fuel pump monitor circuit shows no power - Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits. The fuel pump circuit lost power at one time or another.

Look for a failing fuel pump relay, bad connections or broken wiring. The fuel pump relay is located under the Mass Air Meter on Fox bodied stangs built after 91. On earlier model cars is under the passenger seat. On Mass Air Conversions, the signal lead that tells the computer that the fuel pump has power may not have been wired correctly. See MAF - Mustang Mass Air Conversion - StangNet - The Mustang Network

Diagram of the fuel pump wiring for 91-93 cars.
attachment.php


Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when the test connector is jumpered to the test position. To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. No voltage when jumpered, check the fuel pump relay and fuse links.
attachment.php


Power feed: Look for 12 volts at the pink/black wire (power source for fuel pump relay). No voltage or low voltage, bad fuse link, bad wiring, or connections. Remember that on 92 or later models the fuel pump relay is located under the Mass Air meter. Watch out for the WOT A/C control relay on these cars, as it is located in the same place and can easily be mistaken for the fuel pump relay.

Relay: Turn on the key and jumper the ECC test connector as previously described. Look for 12 volts at the dark green\yellow wire (relay controlled power for the fuel pump). No voltage there means that the relay has failed, or there is a broken wire in the relay control circuit.

attachment.php


91-93 Models:
Using the diagram, check the dark green/yellow wire from the fuel pump relay: you should see 12 volts or so. If not the relay has failed or is intermittent. Check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump is the likely culprit since it is getting power. No voltage there, check the Pink/black wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the dark green/yellow wire, swap the relay.
 
You, sir, are a superstar! Thank you ever so much, this should keep me busy tomorrow, just hope I'll figure it all out.

Right now my money is on the fuel pump itself being the culprit, due to the noise it is making, but we'll see..

Cheers! :nice:
 
Code 96 causes & tests 91-93 models. – KOEO- Fuel pump monitor circuit shows no power - Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits. The fuel pump circuit lost power at one time or another.

Look for a failing fuel pump relay, bad connections or broken wiring. The fuel pump relay is located under the Mass Air Meter on Fox bodied stangs built after 91. On earlier model cars is under the passenger seat. On Mass Air Conversions, the signal lead that tells the computer that the fuel pump has power may not have been wired correctly. See MAF - Mustang Mass Air Conversion - StangNet - The Mustang Network

Diagram of the fuel pump wiring for 91-93 cars.
attachment.php


Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when the test connector is jumpered to the test position. To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. No voltage when jumpered, check the fuel pump relay and fuse links.
attachment.php


Power feed: Look for 12 volts at the pink/black wire (power source for fuel pump relay). No voltage or low voltage, bad fuse link, bad wiring, or connections. Remember that on 92 or later models the fuel pump relay is located under the Mass Air meter. Watch out for the WOT A/C control relay on these cars, as it is located in the same place and can easily be mistaken for the fuel pump relay.

Relay: Turn on the key and jumper the ECC test connector as previously described. Look for 12 volts at the dark green\yellow wire (relay controlled power for the fuel pump). No voltage there means that the relay has failed, or there is a broken wire in the relay control circuit.

attachment.php


91-93 Models:
Using the diagram, check the dark green/yellow wire from the fuel pump relay: you should see 12 volts or so. If not the relay has failed or is intermittent. Check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump is the likely culprit since it is getting power. No voltage there, check the Pink/black wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the dark green/yellow wire, swap the relay.

Sorry to pull up and old post, but I think I have run into a FP relay issue today as I stalled while driving down the road at 70 mph today. Got towed, got home and she fired. I went to test the wiring before the relay and I saw both wires had 9.5 volts, not 12. Is this "bad" and does it mean anything?

Thanks guys!
 
Sorry to pull up and old post, but I think I have run into a FP relay issue today as I stalled while driving down the road at 70 mph today. Got towed, got home and she fired. I went to test the wiring before the relay and I saw both wires had 9.5 volts, not 12. Is this "bad" and does it mean anything?

Thanks guys!

What is the battery voltage at the same time?

Generally speaking, if you have enough voltage to crank the engine over, you have enough for the systems to function (assuming no circuit defects).
 
What is the battery voltage at the same time?

Generally speaking, if you have enough voltage to crank the engine over, you have enough for the systems to function (assuming no circuit defects).

Perfect thank you. Both wires, the accessory and constant, are running 9.65 I believe. The car will run and fire, but when it dies it matches all the other stories of the FP relay failing. Also, went to local auto parts store and autozone and the relays they have are minus the notch that is on the clip side of the plug under the seat.

Thanks!