Wanderer 290
Well-Known Member
I have twin 2001 5.7 TBI B III that at the beginning of the season the port engine had a surge and stall condition from start up. Advancing the throttle Above 1000 rpm or so the surging and stalling stopped.
I moved the IAC from the SB engine to the port engine and the problem continued on the port engine. Swapped ECM’s and the problem continued on the port engine. Finally, I installed a new fuel pump to no avail.
Now the problem is causing a solid tone alarm a few seconds after start up and sometimes an engine shutdown. Per the manual the 2 things that will cause a solid tone alarm is the oil pressure switch and the coolant over temp switch. All indications on the gauges are normal, 40 psi oil and 170* temp. I disconnected the single post wire from the oil pressure switch and the condition went away only to return on the next start up while the oil pressure switch remained disconnected at the switch on top of the block beside of the distributor.
My understanding of the oil pressure switch function is that it goes to ground with no pressure so I don’t understand how it causes a fault while disconnected?
My thoughts are
1. The fault is stored in the ECM and needs cleared.
2.There is a short in the oil pressure switch wiring and it is going ground some where somehow.
Please share your thoughts and any help…
I moved the IAC from the SB engine to the port engine and the problem continued on the port engine. Swapped ECM’s and the problem continued on the port engine. Finally, I installed a new fuel pump to no avail.
Now the problem is causing a solid tone alarm a few seconds after start up and sometimes an engine shutdown. Per the manual the 2 things that will cause a solid tone alarm is the oil pressure switch and the coolant over temp switch. All indications on the gauges are normal, 40 psi oil and 170* temp. I disconnected the single post wire from the oil pressure switch and the condition went away only to return on the next start up while the oil pressure switch remained disconnected at the switch on top of the block beside of the distributor.
My understanding of the oil pressure switch function is that it goes to ground with no pressure so I don’t understand how it causes a fault while disconnected?
My thoughts are
1. The fault is stored in the ECM and needs cleared.
2.There is a short in the oil pressure switch wiring and it is going ground some where somehow.
Please share your thoughts and any help…
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