Oil pressure switched bypassed by mechanic???

C

cxrob1

Member
Joined
Jun 13, 2013
RO Number
33298
Messages
4
Hi,

I have a 97' Searay with a 4.3L LXGen+

I had my mechanic do some maintenance on the boat and after all this was done, he started the boat and it would run a few seconds and stall. (Prior to his visit I had the boat running and it didn't stall at all). Part of the work he had done was replace the oil sensor since it was not reading anything on the guage.

His diagnosis was the carb had to be rebuilt. I asked him if there was anything he moight have overlooked since it didn't stall before he worked on it. His answer of cause = No.

So.... I agreed to have the carb rebuilt and went the extra yard to have the fuel polised (there were minor particles in the fuel so I decided to pay the $200 to have the fuel polished and not risk the $500 I spent to rebuld the carb).

Rebuilt carb was installed (I was not home when he came to do this)

NOW... when I turn the ignition on the fuel pump keeps priming (before he touched the boat, I recall it would humm for a few seconds and stop)..

I called mechanic and answer I got was ..."Huh..don't know maybe the fuel pump got dirt from the bad fuel, if the boat is running use it."

Looking around I now see the wires to the oil pressure safety switch is bypassed (purple/yellow & purple cable tied together) - prior to his repair they were not.

Why would he tie these wires together and not put them back on the sensor where they use to go???

What I'm thinking is he rebuilt the carb (at least I hope he did) replaced it (when I was not home) and found the issue with the stalling was solved. He then realized he mis-diagnosed the issue and may have damaged the pressure switch/cable when replacing the oil sensor and masked it by tying the wires together. I guess it was Sunday and he couldn't get one.

From my research it seems bypassing this oil pressure safety switch is not a good thing as the fuel pump is continously on... correct?

I am thinking to remove the bypass and place the wires back on the switch to see if the engine stalls and confront him. Does it matter which side of the switch the wires (purple/yellow , purple) go?

Thanks
CHris
 
1. Fix the oil pressure sensor. It is tied to the fuel pump and prevents the fuel pump from running when there is not sufficient oil pressure. Bypassing it is a troubleshooting step, not a permanent fix.
2. I would question the carb rebuild and fuel polishing, don't think you needed either. The problem was with the oil pressure / sensor circuit, not the carb.
3. Don't ever use that mechanic again, he is either dishonest or just doesn't know what he is doing.

Agree with your approach on the oil pressure switch - does not matter which way the purple / yellow wires go. The purple/yellow wire supplies power to the fuel pump while the starter is engaged (ie while the key is turned), once oil pressure is reached, the oil pressure switch completes the circuit to the purple wire and continues to supply power to the fuel pump. If you loose oil pressure the fuel pump shuts off.

Sorry you spent $700 for what was at most a $50 repair, but probably a $0 repair, my guess is cleaning the connections at the gauge and the oil pressure sending unit would have fixed your problem. Especially if it was all working when you put the boat away in the fall.
 
There a few of those self proclaimed boat mechanics around. Find a new one.
 
Oil pressure goes to zero. Engine seizes. Fuel pump still pumping fuel possibly causing spillage on a hot seized engine. Anybody but me see anything wrong here.

Take photo's and have a witness of you cleaning the contacts and reconnecting the wires. If indeed cleaning the contacts fixes the problem.....

Confront him/her. Get your money back. Please post results and the bastards name. I don't want any association with anybody who decides my life is worth $700.
 
quote:
Originally posted by KiDa

Oil pressure goes to zero. Engine seizes. Fuel pump still pumping fuel possibly causing spillage on a hot seized engine. Anybody but me see anything wrong here.

Take photo's and have a witness of you cleaning the contacts and reconnecting the wires. If indeed cleaning the contacts fixes the problem.....

Confront him/her. Get your money back. Please post results and the bastards name. I don't want any association with anybody who decides my life is worth $700.

Click to expand...
+1 and then some!
Bill
 
+1 and +1 bypassing the safety aspects of the setup. In theory if you had the engine stopped and a gas leak you could fill the boat with gas. Because of hard starting and the carbs draining the gas after a few days, I have monetary switches that bypass the oil pressure switch which allows me to run the electric fuel pump and charge the system with fuel without cracking forever to get started. The system works well with me. Older crusaders witched from manual fuel pumps to electric.
 
quote:
Originally posted by KiDa

Oil pressure goes to zero. Engine seizes. Fuel pump still pumping fuel possibly causing spillage on a hot seized engine. Anybody but me see anything wrong here.

Take photo's and have a witness of you cleaning the contacts and reconnecting the wires. If indeed cleaning the contacts fixes the problem.....

Confront him/her. Get your money back. Please post results and the bastards name. I don't want any association with anybody who decides my life is worth $700.

Click to expand...


Doesn't even have to be as dramatic as engine seizure. The oil pressure interlock shuts off the fuel pump any time the motor shuts down, stalls etc. With your current setup whenever the key is on you are pumping.
 
I removed the bypass (jumper) wire the mechanic placed and plugged the wires back into the oil pressure switch.

Sure enough ... I pump the throttle see starts and after about a minute she stalls. Started her again and runs a few seconds and stalls. I also hear no humming from the fuel pump.

I ordered a new switch. I'm told the new one is configured a little different and comes with a harness where I will need to splice the wired.
 
I was able to install the new oil pressure switch today and she's no longer stalling. Tune the ingnition on and the fuel pumps humms for about 30 secs and stops (can't remember how longer it hummed in the past didn't remember it being that long) - but once she starts she doesn't stall.

So... I contacted my mechanic and had it out with him.. He deceived me and placed my family at risk by bypassing the fuel pressure switch. Unlikely he will offer to repay me any of the $700 I spent on unnecessary repairs.
 
Chris - I would really put some serious pressure on that mechanic to give you your money back. What he did for/to you is just wrong. To jury rig as sensor on the fuel system is bad - at a minimum that could cause serious damage to your engine if you had an oil pressure related issue - that sensor is there to first shutdown the engine if there is a loss of oil pressure and second to prevent the fuel pump to continue pumping fuel if the engine is not running. #2 to is really a safety issues as others have pointed out. Next, the whole carb rebuild and fuel polishing. A carb rebuild is probably the number one thing that mechanics do when it is not needed - engines running bad, stalling whatever, must be the carb let's rebuild it. I've had more boats and cars with carburetors than I can count - guess how many carburetors I have had rebuild - one! On a 1979 Correct Craft with 1500hrs on it. There are so many things to check first when you think it is a fuel related issue - rebuilding the carburetor is on of the last things you do! Troubleshooting 101 check the simple stuff first! On to the fuel polishing - on a gasoline engine! That's just a rip off plain and simple - I can't imagine he really polished the fuel - that means using an expensive piece of equipment to pump all the fuel out of the tank, filter it, treat it and return it to the tank. This is more common with a diesel engine. He probably poured a $10 bottle of SeaFoam into the take and charged you $200. So this guy is out at the most $10 for SeaFoam (or whatever he used) and $30 for a carb rebuild kit. I don't count his time, because based on what I have heard here, his time is worth $0.

I doubt there is anyone on this forum that would disagree with me. We are not all professional marine people, but most of us know boats and engines enough to smell a rat. Some here probably know more than most of the engineers that designed some of this stuff. This guy owes you $700 and he should count himself lucky to be out of this deal for the cost of a refund. I hope he is an independent guy and not a dealership or a certified mechanic.

This type of thing just really burns me up!
 
Is this mechanic a reputable shop or a shade tree guy free lancing? If he is a shop tell him your taking him to small claims court and then do it if he doesn't return your money. If he's a shade tree mechanic you should toss it up to a lesson learned and be sure to tell everyone you know not to use him! In the end you fixed it yourself and now can trust the work you did yourself. So in the end I say job well done.
Rob
 
quote:
Originally posted by cxrob1

Why would he tie these wires together and not put them back on the sensor where they use to go???
Click to expand...

That's a good question. Perhaps, during his trouble shooting, he bypassed the sensor and the boat still kept stalling. That's when he rebuilt the carb and cleaned the fuel. Boat then stayed running and he forgot that he bypassed the sensor. If he was looking to pad the bill, why didn't he replace the bad sensor and add that to the bill? What was his reason for not finishing the job?
 
quote:
Originally posted by Pa Mikee

quote:
Originally posted by cxrob1

Why would he tie these wires together and not put them back on the sensor where they use to go???
Click to expand...

That's a good question. Perhaps, during his trouble shooting, he bypassed the sensor and the boat still kept stalling. That's when he rebuilt the carb and cleaned the fuel. Boat then stayed running and he forgot that he bypassed the sensor. If he was looking to pad the bill, why didn't he replace the bad sensor and add that to the bill? What was his reason for not finishing the job?

Click to expand...


I'll tell you why. Because the carb didn't need to be rebuild for $500 to begin with. Throw on top of that $200 for scrubbing the fuel and then when the "mechanic" started the engine, it continued to stall. Bypassing the sensor was his way of trying to hide his incompetence. Call me cynical, but I know you're all thinking the same thing.

Ps. Sorry Bill, I see you beat me to the punch.
 
Hi Guys,

Just to clear one thing up... On the fuel polishing... the mechanic referred me to another guy who came with a special pump and filter. But my mechanic referred me to this guy after he knew the rebuilt carb wasn't the issue nor the fuel. I do plan to call him back again to get some money back from him. As I mentioned previously, he lives in the same town and works on referrals... needless to say my time on the docks this summer will include sharing my experience with many other boaters on the dock to warn them of this mechanic.
 
This would not sit well with me! He lied to you and removed a safety feature to try to cover for it. I really hope you have no plans of ever using him in the future! I glad you were able to figure this out for yourself!
 
As a boater and a former auto mechanic, I find your 'mechanic's' work on your engine beyond unacceotable. Bypassing a safety switch should only be done in an emergency or for testing purposes. Leaving it bypassed is leaving everyone at risk for a catatrophe. First, your costs should be returned. He charged you for unnecessary repairs. I don't care what he paid the fuel polisher; that's his loss. Second, a formal complaint should be lodged with the Better Business Bureau in your area. Third, if he is a certified Mercruiser mechanic, a report should be filed with Mercruiser. I may sound harsh, but the way he handled this problem put you and your guests at risk and damages the reputation of the entire marine repair business. Mistakes happen; misdiagnoses happen. An honest mechanic admits his mistake, apologizes, swallows any costs involved, and never intentionally leaves a customer at risk of injury or worse. Hy
 
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