Engine stubbles at idle speed

[Gjac]

The MH in my signature has become Ihard to start and falls flat when I give it the gas. The problem seams to be progressing. Changed fuel filter before trip, ran can of seaform. Still does it when it's hot. Runs normal once im driving.

[enblethen]

They are both Oreilly pages. They changed there site.

[Gjac]

mike brez wrote:

enblethen wrote:
The fuel pump sending unit has three wires not one.
oil pressure sending unit
As for testing, it is hard to verify that the contacts are not pitted to the point of increasing resistance that causes the voltage drop.
I noticed that my oil pressure gauge had changed slightly indicating higher oil pressure. I changed the sending unit and the gauge started registering closer to where it was.
The fuel pump relay only operates to pressurize the system. It does not operate under normal pump operation. It runs for 2 to 10 seconds when ignition is first turned to "on".

If that was directed to me I was talking oil pressure switch

. I found the one wire from the fuel pump relay and followed it down and it went to some kind of switch , it was difficult to see I could only feel it. It was on the frame not on the block.

[Gjac]

enblethen wrote:
No, I messed up. Left side
Fuel pump relay

. I can't view either link you sent.

[mike_brez]

enblethen wrote:
The fuel pump sending unit has three wires not one.
oil pressure sending unit
As for testing, it is hard to verify that the contacts are not pitted to the point of increasing resistance that causes the voltage drop.
I noticed that my oil pressure gauge had changed slightly indicating higher oil pressure. I changed the sending unit and the gauge started registering closer to where it was.
The fuel pump relay only operates to pressurize the system. It does not operate under normal pump operation. It runs for 2 to 10 seconds when ignition is first turned to "on".

If that was directed to me I was talking oil pressure switch

[Gjac]

dellete dup post

[enblethen]

No, I messed up. Left side
Fuel pump relay

[Gjac]

enblethen wrote:
I cannot here my pump without putting screw driver against tank and ear.
FYI the fuel pump relay is on the right side of engine compartment on a sheet metal panel along a tubular brace.

Are you saying it is on the passenger side? I found a relay on the drivers side that is black oval shaped about 2 ins long with 5 spade connections 3 large and 2 small.

[enblethen]

No the oil pressure sending unit does not control relay. It is controlled from the ECM.

[enblethen]

I cannot here my pump without putting screw driver against tank and ear.
FYI the fuel pump relay is on the right side of engine compartment on a sheet metal panel along a tubular brace.

[Gjac]

enblethen wrote:
The fuel pump sending unit has three wires not one.
oil pressure sending unit
As for testing, it is hard to verify that the contacts are not pitted to the point of increasing resistance that causes the voltage drop.
I noticed that my oil pressure gauge had changed slightly indicating higher oil pressure. I changed the sending unit and the gauge started registering closer to where it was.
The fuel pump relay only operates to pressurize the system. It does not operate under normal pump operation. It runs for 2 to 10 seconds when ignition is first turned to "on".

. Thanks Bud, I also put my fingers on the relay and can't feel any clicking, are you saying that the oil pressure sending unit controls this relay? I could not open the link you sent me, but what I think is the sending unit is about 1 in in Dia and 3 ins long and has about 5 wires attached to it.

[Gjac]

I turned key on and had my son listen for hum in the fuel pump in the rear of the MH and there was no hum or noise of it being activated. What I can't figure out is when I start engine I see fuel squirting into tbi.

[enblethen]

The fuel pump sending unit has three wires not one.
oil pressure sending unit
As for testing, it is hard to verify that the contacts are not pitted to the point of increasing resistance that causes the voltage drop.
I noticed that my oil pressure gauge had changed slightly indicating higher oil pressure. I changed the sending unit and the gauge started registering closer to where it was.
The fuel pump relay only operates to pressurize the system. It does not operate under normal pump operation. It runs for 2 to 10 seconds when ignition is first turned to "on".

[Gjac]

Thanks Mike have you ever changed your relay? I know you dropped the tank to change your fuel pump. Any symptoms of a failing relay or failing fuel pump?

[mike_brez]

Gary it's been awhile but it is on the left side of block(drivers side)and has a single wire going to it. You may be able to follow wire down from the relay.

[Gjac]

Is ther any way to test the sending unit , fuel pump relay, or fuel regulator?