1999 Volvo 5.7 GSI fuel pump issues

[shanayney]

Hi, new to forum.

1999 Volvo won't start. With key on, there is no (2 second) voltage at low pressure pump. Pump develops 8psi when 'hotwired'.

Checked relays. OK. To be sure, took relays from other engine, installed, no better. Tried same with ECM.


Any ideas?

[Don S]

What's the full model number or even the SN of your engine?
How and where did you "Hot Wire" the fuel pump? relay removed and jump across the relay sockets, or + & - to the pump directly?

[shanayney]

Thanks for the reply. I jumped from the relay socket. I will have to go back to the boat for the SN.

[Don S]

When you go to get the number, take your meter and do some testing while you are there.
Reference the picture below.
With fuel pump relay removed, and the ign. switch ON, touch the black lead to a good clean ground, then touch the red lead to terminals 86 and 30 you should see approximatly battery voltage at those terminals. If not, you found your problem in the wiring from the fuse or circuit breaker to the relay socket. If they are ok, move on to the next step.

SHUT OFF THE IGNITION SWITCH

Now, hook the RED lead of your meter to terminal 86 and the black meter lead to terminal 85
Now, while you watch the meter, have someone turn the ignition switch to the run (NOT start) position. You should see approximatly battery voltage for 2 seconds. If not. Well, we need to know exactly which model you have for that.




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[shanayney]

I will get back to the boat this weekend. Thanks so much for the help.

[shanayney]

Didn't get to the boat until today. Confirmed the following results:

The first test shows battery voltage at both 86 and 30 terminals.

The second test failed to produce voltage when keyed on.

The engine is 5.7GSI PWTR (S/n 4110190568 3868947).

Neither engine currently runs (one seized). Also, found today neither engine is priming when ignition switched on (can't assume that either ECM is good).

The boat sat for months with flat batteries and then wouldn't start with new batteries. Perhaps low voltage or a mistake when installing batteries hurt the ECMs, or?

[Don S]

You mentioned you hot wired the socket and the fuel pump ran, well, 1 of them ran anyway. Did both run? If so, then the grounds on the pumps are good. Since you only got 8 psi, I would guess you only checked the low pressure pump pressure and not the high pressure pump. That is back on the Vapor seperator tank. Check it too, to make sure the pump will run.

On to checking the rest of the system.
Since you have power to the relays, we have to check the path to ground for the relay. Back to the ECM.
Disconnect the battery ground.
Then disconnect the J1 connector from the ECM, then with an ohm meter check for continuity between a good engine ground and terminals 4-5-20 of the J1 connector (NOT the ECM itself). Those are all grounds to the engine and must be good. If they are ok, again with an ohm meter, check terminal J1-23 on the connector, to terminal 85 on the relay socket (Black wire with yellow stripe). If that is good, then you have a bad ECM.


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[shanayney]

I performed the tests and it points to the ECM. Volvo wants over $1000.

Thanks for the input, and I'll update you on the result.

[shanayney]

To be sure of the diagnosis, I installed the bad ECM on a good running 1999 5.7GSI. Same fault, ECM(s) confirmed bad (both engines).

Double checked pricing at dealer, wants $1700.00+ each (list). Any lower cost options?