Mercruiser 7.4 PMI problème

[dinopaul]

Hello everyone,
I have a problem with one of my two engines, 1998 Mercruiser 7.4 PMI, it starts without problem and after a few minutes it stops, if I want to restart it I no longer hear the fuel pump, I am waiting for a ten minutes and the pump restarts and the engine also for a few more minutes and it stops again.
Has anyone encountered this problem?
Thank you all
Paul

 

[hottoddie]

Good chance you have a faulty fuel pump relay. Pretty common.

 

[scoflaw]

When it happens again see if you have 12v. to the pump, they don't last forever.
If you replace the pump this is a good one for short money. Airtex E11004

 

[dinopaul]

Good chance you have a faulty fuel pump relay. Pretty common.

Hello
no, but does a relay work or does it not work so it should not have intermittent?
Thank you

 

[dinopaul]

When it happens again see if you have 12v. to the pump, they don't last forever.
If you replace the pump this is a good one for short money. Airtex E11004

I haven't tested yet, I'm going to the boat tomorrow and will test.
Thanks

 

[hottoddie]

Hello
no, but does a relay work or does it not work so it should not have intermittent?
Thank you

Seen intermittent relays on several occasions. I have friends that carry spares on board.

 

[Espos4]

Hello
no, but does a relay work or does it not work so it should not have intermittent?
Thank you

Electrical items can be affected by heat. A relay can very well be intermittent.

 

[dinopaul]

I took a relay on the other engine and always nothing the fuel pump did not start,
I read elsewhere that IAC could cut the fuel pump, I therefore dismantle the covers to see where was the IAC and I saw that the ARRESTOR-FLAME was very very dirty and almost clogged,
in time the pump started and I started the engine without the ARRESTOR-FLAME, it run 10 seconds and stop.

I cleaned and reassembled the ARRESTOR-FLAME and I started the engine for 1 hour without problem,
then twice for 15 minutes without problem.

My question is, do you think a sender can tell to the calculator:

"I have too much air, there is a probleme, cut the fuel pump"
or
"I don't have enough air there is a probleme cut the fuel pump"

Thank you.

 

[scoflaw]

Nope, not with that ECM.

 

[dinopaul]

Nope, not with that ECM.

thanks
I must continue my research

 

[scoflaw]

You got something flakey going on, wiring, relay, fuel pump, ecm. Swapping that ecm would be quick and easy

 

[dinopaul]

You got something flakey going on, wiring, relay, fuel pump, ecm. Swapping that ecm would be quick and easy

ecm is new it have 10h, the relays are ok i tested them, i am going to the boat tomorrow i will look for the pump and the wiring

 

[scoflaw]

What ecm did you get? Those mefi 3's have been long gone. Refurb? Mefi 4 with a conversion harness?

 

[dinopaul]

What ecm did you get? Those mefi 3's have been long gone. Refurb? Mefi 4 with a conversion harness?

I don't know if it's mefi3 or 4 the part# is 861736R1 and they are reman

 

[scoflaw]

I'd have the volt meter handy for testing the next time it fails. Start with power to the fuel pump and then move on to the relay, power to it and leaving.

 

[Chris-380]

I don't know if it's mefi3 or 4 the part# is 861736R1 and they are reman

My 2000 is mefi3, don’t know that it would help you though….

 

[dinopaul]

I'd have the volt meter handy for testing the next time it fails. Start with power to the fuel pump and then move on to the relay, power to it and leaving.

will check