fuel pump looses power...
Mudding
Joined: Apr 2010
Posts: 140
Likes: 2
From: With the boss
When the car did run, did you have momentary cut-outs? If so, bad contacts at the FI relay (either burnt contact inside or loose AMP comnnectors in the connector block) -> easy to fix
Try measuring the voltage at the pump, you should have a healthy 12V and more. If not, it's not the pump motor, it's the relay/contacts/wiring.
General Question: Could it be the emergency fuel cut off? and how can he check?
SD
Try measuring the voltage at the pump, you should have a healthy 12V and more. If not, it's not the pump motor, it's the relay/contacts/wiring.
General Question: Could it be the emergency fuel cut off? and how can he check?
SD
Recovery Vehicle
Joined: May 2009
Posts: 1,081
Likes: 1
From: Punta Gorda, FL
The fuel pump relay is semi-easy to crack open once it's out, using a small flat head you can pry the cover off. You can clearley see the contacts. I would try cleaning them up real good, and maybe even pluging it in with the cover off and see which, if any, relay de-energizes after the 10 sec time-out period.
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Mudding
Joined: Sep 2010
Posts: 240
Likes: 0
Yes it did momentarily cut off when driving at first, now nothing. I'll pop that open tonight when I get home and look.
And yea that red cable is for te sub that's not in it right now lol. I used the sub an amp from my mustang on the cross country trip so I had to run wiring for it. I ran on that side cuz my intention is to mount a sub on the back door eventually where the stock was.
And yea that red cable is for te sub that's not in it right now lol. I used the sub an amp from my mustang on the cross country trip so I had to run wiring for it. I ran on that side cuz my intention is to mount a sub on the back door eventually where the stock was.
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Mudding
Joined: Sep 2010
Posts: 240
Likes: 0
From rave...
So i'm finally back home and had a chance to really dig into the rave manual, and according to this it seams my problem is the main relay went out and the reason i'm only getting power at the pump for a short time is the fuel pump part priming the system right? imma open up the relay in the morning and verify this.
Relay module
The engine management system employs a relay
module, which houses the main relay and the fuel
pump relay.
Main relay
The main relay supplies the power feed to the ECM
with a tap off to feed the fuel injectors (8 amps) and
air flow sensor (4 amps). This relay is controlled by
the engine management ECM. This enables the ECM
to remain powered up after ignition is switched off.
During this ’ECM power down routine’ the ECM
records all temperature readings and powers the
stepper motor to the fully open position. Failure of this
relay will result in the engine management ECM not
being switched on resulting in engine not starting due
to absence of fuel and ignition.
Fuel pump relay
The fuel pump relay is fed from the ignition relay and
controlled by the engine management ECM. The relay
is activated in ignition key position 2 to prime the fuel
system for a period of time controlled by the ECM.
Failure of this relay will result in no fuel pressure.
The engine management system employs a relay
module, which houses the main relay and the fuel
pump relay.
Main relay
The main relay supplies the power feed to the ECM
with a tap off to feed the fuel injectors (8 amps) and
air flow sensor (4 amps). This relay is controlled by
the engine management ECM. This enables the ECM
to remain powered up after ignition is switched off.
During this ’ECM power down routine’ the ECM
records all temperature readings and powers the
stepper motor to the fully open position. Failure of this
relay will result in the engine management ECM not
being switched on resulting in engine not starting due
to absence of fuel and ignition.
Fuel pump relay
The fuel pump relay is fed from the ignition relay and
controlled by the engine management ECM. The relay
is activated in ignition key position 2 to prime the fuel
system for a period of time controlled by the ECM.
Failure of this relay will result in no fuel pressure.
Mudding
Joined: Apr 2010
Posts: 140
Likes: 2
From: With the boss
If they are clean then the problem is not the relay.
Has someone tested the socket? In mine a dipstick at the stealership inserted the continuity tester into the socket and widened the connectors. The car would then cut out fo a few seconds at random and at times would not start (fire up) without some wiggling of wires under the hood.
This is hard to check so just tighten the connectors by inserting a hard metal point (like a tiny scewdriver but harder metal like a small ellen key) between the connector and the plastic to "close" the gap of the spade connectors.
I'd like to know the voltage at the pump terminals.
SD
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Mudding
Joined: Sep 2010
Posts: 240
Likes: 0
they look pretty damn clean. voltage at the white/purple was 12.xx for about 10 seconds then nothing, i didn't test at the green cuz isn't that for the gauge?
if that's not bad whats my next thing to check? i suppose the inertia switch could fail out of no where but wouldn't i not get any fuel then and not just priming fuel?
if that's not bad whats my next thing to check? i suppose the inertia switch could fail out of no where but wouldn't i not get any fuel then and not just priming fuel?
TReK
Joined: Sep 2010
Posts: 2,073
Likes: 6
From: Ketchikan, Alaska, USA
I could be wrong, but on some vehicles, the pump will only turn on for a few secs to pressurize the system. Then it would remain off until the ECM received a signal from other sensors that the engine did start and is running. Then the ECM would energize the pump continuously. So the problem may be with whatever sensor is supposed to tell the ECM that the engine is running. Not the relay or pump.