No start, Fuel pump?
06-13-2011, 07:23 PM
#1
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Join Date: Aug 2007
Location: Philadelphia
Posts: 97
No start, Fuel pump?
Hey fellas, I put less than 2000 miles a year on my car due to having a company vehicle.
Last time I drove it was two weekends ago and performed great, but yesterday I couldn't start my car. I noticed my fuel pump being energized but then it never shut off.
1. I dont have a fuel gauge at this time.
2. battery and starter is good.
3. Ignition starts fuel pump but never shuts off, does this means not enough fuel is getting to the engine?
4. Fuel tank is 1/4 full and fuel filter is less than a year old.
5. Can it be a computer going bad?
Engine came on, idle normal, take out of the driveway and died again.
Any input is greatly appreciated.
Last time I drove it was two weekends ago and performed great, but yesterday I couldn't start my car. I noticed my fuel pump being energized but then it never shut off.
1. I dont have a fuel gauge at this time.
2. battery and starter is good.
3. Ignition starts fuel pump but never shuts off, does this means not enough fuel is getting to the engine?
4. Fuel tank is 1/4 full and fuel filter is less than a year old.
5. Can it be a computer going bad?
Engine came on, idle normal, take out of the driveway and died again.
Any input is greatly appreciated.
06-13-2011, 11:47 PM
#4
6th Gear Member
Join Date: Oct 2005
Location: st clair shores MI
Posts: 6,028
you can do a quick check....just pull the schrader valve on the rail. you'll need an adapter i wanna say it's 1/16-1/8 npt but not 100%
then just hook up a fp guage and see what it does. 36 psi with key on is good
then just hook up a fp guage and see what it does. 36 psi with key on is good
06-14-2011, 03:27 AM
#5
Banned
Join Date: Dec 2005
Location: Lil' Rhody
Posts: 22,376
If the FP doesnt work, there are a few steps you can take to isolate the problem.
Step 1: Verify the pump works.
Run a 12v+ lead into the trunk, to the inertia switch (interior, drivers side tailight area)
if pump works, go to step 2, If pump doesn't work, replace pump.
Step 2: Fuel pump relay
Should be located under drivers side seat (some have a relay mounted in the engine bay as well) Jump power to the correct pin of the relay, fuel pump should turn on.
If pump works, wiring from relay to pump (including inertia switch) is good.
Bench test relay: Pins 86 and 85 are the activating legs of the relay, pin 30 is voltage input, and pins 87/87a are the switched output.
I just lost my train of thought... but this wiring diagram should help
http://www.veryuseful.com/mustang/te...ng_Diagram.gif
Step 1: Verify the pump works.
Run a 12v+ lead into the trunk, to the inertia switch (interior, drivers side tailight area)
if pump works, go to step 2, If pump doesn't work, replace pump.
Step 2: Fuel pump relay
Should be located under drivers side seat (some have a relay mounted in the engine bay as well) Jump power to the correct pin of the relay, fuel pump should turn on.
If pump works, wiring from relay to pump (including inertia switch) is good.
Bench test relay: Pins 86 and 85 are the activating legs of the relay, pin 30 is voltage input, and pins 87/87a are the switched output.
I just lost my train of thought... but this wiring diagram should help
http://www.veryuseful.com/mustang/te...ng_Diagram.gif
06-15-2011, 07:55 PM
#6
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Thread Starter
Join Date: Aug 2007
Location: Philadelphia
Posts: 97
Thanks guys,
I checked the fuel pressure at 38 to 40 psi with ignition on so fuel pump is good.
Also checked fuel pump relay (mine was located under the mass air sensor next to "WAC switch") which happens to be exact same type relay.
Checked ohm reading at the coil between 85 and 86, both read 70 ohms resistence.
Swapped each relays and same problem, it came on for 5 min idle time and shut off.
What else should I check ?
I checked the fuel pressure at 38 to 40 psi with ignition on so fuel pump is good.
Also checked fuel pump relay (mine was located under the mass air sensor next to "WAC switch") which happens to be exact same type relay.
Checked ohm reading at the coil between 85 and 86, both read 70 ohms resistence.
Swapped each relays and same problem, it came on for 5 min idle time and shut off.
What else should I check ?
06-17-2011, 03:22 PM
#7
1st Gear Member
Thread Starter
Join Date: Aug 2007
Location: Philadelphia
Posts: 97
Installed new ignition module last night with same result.
Does anyone know about PIP sensor in distributor head?
It seems like fuel injectors are not getting energized which gets the power from ECU.
What code scanner should I get?
Does anyone know about PIP sensor in distributor head?
It seems like fuel injectors are not getting energized which gets the power from ECU.
What code scanner should I get?
06-18-2011, 12:46 PM
#8
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Join Date: Aug 2007
Location: Philadelphia
Posts: 97
Update...
Car sat there for 24 hours, restart the car and engine started like nothing was ever wrong before. It idles normal, throttle response was good, when it reached normal operating temp truned car off to restart and back to square one having same issues.
Today, checked 12v at ignition coil, pulled a spark plug and verified good sparks.
At the same time found injectors not getting energized.
1. what turns fuel pump off during normal start ?
2. what else keep injectors from coming on ?
3. Do I have a bad ECU ?
Car sat there for 24 hours, restart the car and engine started like nothing was ever wrong before. It idles normal, throttle response was good, when it reached normal operating temp truned car off to restart and back to square one having same issues.
Today, checked 12v at ignition coil, pulled a spark plug and verified good sparks.
At the same time found injectors not getting energized.
1. what turns fuel pump off during normal start ?
2. what else keep injectors from coming on ?
3. Do I have a bad ECU ?
Last edited by Devil Dog; 06-18-2011 at 12:58 PM.
06-18-2011, 06:54 PM
#9
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Join Date: Aug 2007
Location: Philadelphia
Posts: 97
Purchased a code scanner from Pep boys, installed it and steady light came on.
Carefully followed instruction and turned ignition to "on", waited for over two minutes to get any flashing code but nothing happened as if it was grounded.
So I said F#$% it, decided to pull ECU out, take it apart to inspect the main board and found nothing out of ordinary (no sign of burned resistors).
I think im ready to swallow my pride and take it to a mechanic or pump my 45 acp in to it.
Carefully followed instruction and turned ignition to "on", waited for over two minutes to get any flashing code but nothing happened as if it was grounded.
So I said F#$% it, decided to pull ECU out, take it apart to inspect the main board and found nothing out of ordinary (no sign of burned resistors).
I think im ready to swallow my pride and take it to a mechanic or pump my 45 acp in to it.
06-19-2011, 09:45 AM
#10
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Join Date: Aug 2007
Location: Philadelphia
Posts: 97
Today I decided to check continuity between fuel injectors and ECU plug adapter.
Checked 3 injector plugs (others are buried under upper intake) to ECU adapter and ohm reading were 0.2ohms.
So I decided to give another look at ECU board and lord behold, I found the freaking problem. There are 3 small blue capacitors on the board and one was just barely hanging due to capacitor leaking on the board.
It looks like it's been leaking for a while due to corrosion build up on the board base.
I guess 19 years of service was worth it....
Checked 3 injector plugs (others are buried under upper intake) to ECU adapter and ohm reading were 0.2ohms.
So I decided to give another look at ECU board and lord behold, I found the freaking problem. There are 3 small blue capacitors on the board and one was just barely hanging due to capacitor leaking on the board.
It looks like it's been leaking for a while due to corrosion build up on the board base.
I guess 19 years of service was worth it....