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Crusader 454 xli no fuel pump power - looking for some diagnostic help

T

Tc702

New member
Crusader 7.4 454 xli with MPI, mefi2.

turn key to run, no priming/running of fuel pump takes place. Have power to pink input wire at relay, have ground, no signal from ecu to green/white, and obviously no output to pump’s pink wire. I’ve tried jumping green/white to ground, and nothing. Have continuity on green/white from ecu to relay, have ground at pump itself. No codes at all with a diy “scanner” light.

I’ve done a quick wiggle test of the harness in different areas, verified fuses are good, swapped relays with other engine that are verified good, swapped ecu with other engine. Stumped?

what else could cause fuel pump to not prime/run? It’s my understanding the green/white wire is signal from ecu to flip relay and send power to pump but this does not do anything. What am I missing? Suggestions?
 
you won't see any fuel pump related codes with the MEFI-2....

Jumping the green/white to ground was not a good thing to do as that could have shorted out the fuel pump driver circuit in the ECU...

try jumping the fuel pump's hot wire to a fused +12VDC source...unplug the relay and use the jumper in the relay's connector sockets...if the pump runs, then there is a control issue...make sure the pump is good before worrying about anything else...then worry about the relay controlling the pump.

FWIW, I've seen more than one MEFI-2 system where the 'prime' function at startup went south...

Finally, the MEFI-2 uses the reference pulses out out the distributor to detect the engine is running which enables the fuel pump...if the pump runs with the jumper, I'd look for spark next...
 
makomark said:
you won't see any fuel pump related codes with the MEFI-2....

Jumping the green/white to ground was not a good thing to do as that could have shorted out the fuel pump driver circuit in the ECU...

try jumping the fuel pump's hot wire to a fused +12VDC source...unplug the relay and use the jumper in the relay's connector sockets...if the pump runs, then there is a control issue...make sure the pump is good before worrying about anything else...then worry about the relay controlling the pump.

FWIW, I've seen more than one MEFI-2 system where the 'prime' function at startup went south...

Finally, the MEFI-2 uses the reference pulses out out the distributor to detect the engine is running which enables the fuel pump...if the pump runs with the jumper, I'd look for spark next...
Click to expand...


thanks for the insight. I get nothing jumping the wire running to pump in relay socket. Do you know if the pink wire at relay to fuel pump splits anywhere or does it only feed the fuel pump? I tried swapping computers from other engine that works as it should and have same issue.
 
makomark said:
you won't see any fuel pump related codes with the MEFI-2....

Jumping the green/white to ground was not a good thing to do as that could have shorted out the fuel pump driver circuit in the ECU...

try jumping the fuel pump's hot wire to a fused +12VDC source...unplug the relay and use the jumper in the relay's connector sockets...if the pump runs, then there is a control issue...make sure the pump is good before worrying about anything else...then worry about the relay controlling the pump.

FWIW, I've seen more than one MEFI-2 system where the 'prime' function at startup went south...

Finally, the MEFI-2 uses the reference pulses out out the distributor to detect the engine is running which enables the fuel pump...if the pump runs with the jumper, I'd look for spark next...
Click to expand...

also do you happen to know what input does the computer use to ground green/white? Is that triggered by distributor?
 
Tc702 said:
thanks for the insight. I get nothing jumping the wire running to pump in relay socket. Do you know if the pink wire at relay to fuel pump splits anywhere or does it only feed the fuel pump? I tried swapping computers from other engine that works as it should and have same issue.
Click to expand...

Did you check for power at the 10amp breaker on the engine panel?

If the pump works when you put 12v to it, I'd check power to the breaker on both sides, then look at the relay.
 
the ECU uses the presence of reference pulses from the distributor to enable the fuel pump...

if you jump the relay (what you are calling the pink wires) and the pump doesn't run, sounds like the pump is ready for replacement or the wiring from the relay socket to the pump is bad.

Would seriously suggest you get the MEFI manual off of the internet...the delphi version is fine...there may be a couple differences in the wiring diagrams (usually the colors used) but they can be traced to verify.
 
makomark said:
the ECU uses the presence of reference pulses from the distributor to enable the fuel pump...

if you jump the relay (what you are calling the pink wires) and the pump doesn't run, sounds like the pump is ready for replacement or the wiring from the relay socket to the pump is bad.

Would seriously suggest you get the MEFI manual off of the internet...the delphi version is fine...there may be a couple differences in the wiring diagrams (usually the colors used) but they can be traced to verify.
Click to expand...

I have ruled out the fuel pump relay. Now I am starting to focus on the ignition control module. My understanding is that if the ECU does not receive pulses from the ICM, it will shut off the fuel pump. Does this make sense that even during cranking, the fuel pump would be shut down if the ECU does not receive the pulses from the ICM?
 
You can check the MEFI manual to be sure but i think that cranking and running are two different states for the ECU to be controlling the fuel pump...the cranking is the nominal two second prime mode and that is it...

if you are getting sparks at the plugs, its highly likely that the ignition module is providing the correct signals to the ECU...
 

I'm sure you have resolved your fuel pump issue by now. I'm new on this forum but thought I'd throw in my experience for the next guy who has fuel pump problems. I've owned twin 454 XLi's for a little over a year and have learned more than I ever wanted to know. The first issue was the engine starting for 10 seconds, stalling and not re-starting. Took a week before we discovered what we should have checked first. The connector to the fuel pump was corroded and contacts stretched. Found part at NAPA for $15.00! For the past month and a half, I've had a different problem with the engine shutting down after a 1-2 hour trip and a shut down longer than a fuel stop e.g. lunch for 1-2 hours. Engine would start but shut down after about 5 minutes at idle. Found that there was fuel pump pressure, but no fuel in pump. Once primed, problem "solved".​

See discussion in previous thread "Crusader 454XL-TB Starting/running problems".​

​

 
CaptJoe3 said:

I'm sure you have resolved your fuel pump issue by now. I'm new on this forum but thought I'd throw in my experience for the next guy who has fuel pump problems. I've owned twin 454 XLi's for a little over a year and have learned more than I ever wanted to know. The first issue was the engine starting for 10 seconds, stalling and not re-starting. Took a week before we discovered what we should have checked first. The connector to the fuel pump was corroded and contacts stretched. Found part at NAPA for $15.00! For the past month and a half, I've had a different problem with the engine shutting down after a 1-2 hour trip and a shut down longer than a fuel stop e.g. lunch for 1-2 hours. Engine would start but shut down after about 5 minutes at idle. Found that there was fuel pump pressure, but no fuel in pump. Once primed, problem "solved".​

See discussion in previous thread "Crusader 454XL-TB Starting/running problems".​

​

Click to expand...
My slip neighbor has a similar problem that I am trying to help with in a 1995 Silverton's 454 engine. The engine cranks........no alarm buzzer in the cockpit and no power to fuel pump. The alarm should start as soon as the key is activated and quit when the engine starts. Tough working onit without a circuit diagram but even with a diagram, still a tough resolve. Suggestions???

Thx
Foggysail
 
you don't say which flavor of 454 you have...so it depends...

the no alarm with the key RUN, could be no power flowing thru the key switch OR a bad oil pressure switch...

The fuel pump not running for a few seconds when the key is switched to RUN, could be a bad connector, a bad relay, or another issue in the wiring...on the TBI setups. There were some wiring changes in the early years and not every manual captures all of the changes...on the carb engines, the fuel pump wiring is much simpler, and depend on +12VDC being present on the ignition lead with the key to RUN, and an oil pressure switch (different from the alarm switch) to implement the safety requirement. For these, the easiest test for the pump is to run a fused jumper directly to the pump...
 
If your 454 is an XLi TBI (Throttle Body Injection). I can offer the possibility is the Fuel Pump Connector. NAPA part number CRB 218457. It's a good place to start. The connectors were corroded. Other issues followedg regarding the fuel pump which i will include in a separate post. The connector solved the failure to start, continue running issue, but then I began having shut down issues after a hot re-start. We determined "vapor lock" was the problem and due to the return fuel line to a second inlet in the fuel pump. Unable to find a suitable "Marine" fuel pump (16-20 psi), my mechanic disconnected the return from the fuel pump which he capped off, and returned to the fuel tank, which already had the necessary plumping. Problem solved. It was suggested that a Carter P5001 pump for replacement, but I was told by a Carter rep that it was NOT for marine use (contradicting what a Carter rep told a previous poster) We, (the forum) need to resolve this contradiction. I would much rather have an approved pump than a "jerry" rigged one.
 
makomark said:
you don't say which flavor of 454 you have...so it depends...

the no alarm with the key RUN, could be no power flowing thru the key switch OR a bad oil pressure switch...

The fuel pump not running for a few seconds when the key is switched to RUN, could be a bad connector, a bad relay, or another issue in the wiring...on the TBI setups. There were some wiring changes in the early years and not every manual captures all of the changes...on the carb engines, the fuel pump wiring is much simpler, and depend on +12VDC being present on the ignition lead with the key to RUN, and an oil pressure switch (different from the alarm switch) to implement the safety requirement. For these, the easiest test for the pump is to run a fused jumper directly to the pump...
Click to expand...

I need to get better information pertaining to the engine (slip neighbor's boat). As I understand the problem with the information I have, I believe there is a relationship between the buzzer and the fuel pump. I did measure the voltage at the pump connector and there was none. What I did not check but will next weekend is whether there is a spark being applied to the plugs while cranking. I read someplace here in the forum that the (or at least some) pumps are pulsed. That makes a lot of sense by pumping essentially on RPM demand.

My getting into this mess was an attempt to be a good slip neighbor. For certain he will absorb a big bucks charge at the marina to have them do the repair and in the end he may just be billed for the labor without the problem getting resolved.
 
I have a 1994 Tiara with twin 454XL (carburetors) Crusaders. The starboard engine starts right up but shuts down after 30 seconds. Interestingly, the alarm comes on about 10 seconds prior to engine stoppage. Does this sound like a fuel pump or ECU connector problem? Thanks
 
my initial thought is loss of oil pressure causes the fuel pump to shut off and triggers the alarm...what does the oil pressure gauge show?
 
i am also having problems with 454xli. was running then we slowed down went to power up and starboard just died. about an hour later she fired up. we swapped coil. problem seemed to go away until recently went out at idle and starboard motor just died. now all she does is crank. have power to the fuel pump but seems low on voltage?? port fires up strong.
 
its a SPDT switch...the common terminal feeds the fuel pump, the red/yel supplies current to the fuel pump when cranking(N.C. terminal) and the purple wire supplies current with the engine running (N.O terminal)...
 
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