what do I try next ""follow up""

Cactus52

Cadet
Joined
Aug 7, 2010
Messages
10
Hey all:

The original posting is below

Since then I have replaced the fuel pump and plug wires and the coil, lubed the distrubtor wts and had it re-timed and it was good. I am still having the same issue!!!! So What do I try next short of replacing the engine????

I have posted this problem before but I am now gonna give a detailed history and see if it jogs out some other responses....

Volvo penta AQ260a engine and a Volvo 280 outdrive......

I have a 85 Bayliner 2550 Ciera. I have had it two months or so and do not know the previous owner or history. For the first month I had no issues, I went out daily and cruised around for an hour or so no problems. Then I had friends coming up so I went across the marina and got gas and a pumpout and overheated. I changed the impeller and thermostat so call it fixed. The next day I went out with friends and ran it for a couple of hours, tubing etc. Thats when it all started. Cruising at 3500 rpm's or so it started coughing and running rough and I had to throttle it back to keep it smooth. This continued till I was at idle and it died. I took it out of the water and to a trustworthy shop and they gave it a complete tune up. The base timing was set at 8 degrees PTDC and it was changed to 8 BTDC (I do not know the advanced). I got it back and it ran better than it ever has, for about two hours then the same bogging down as described above. Tow number 2. I then had the same mechanic come out and he checked for water and found none and added a water separator. I took it out again and it ran great for a bit then the same issues. Tow number 3 I pulled it out again and had the carb rebuilt. Got it back in the water and same story, it ran great then the same but had a fuel smell at cruise then it bogged down again. We looked at everything then. Pulled all filters, nothing. Pulled the feed tube out and siphoned gas out of the bottom and it was water free with little junk. We pulled the distributer cap and found the rotor metal tab was broken so I replaced it along with the cap. I took it to Kelly's Island last night with no issues (about 4 miles) and about halfway back it started again and I was able to limp it back in, but I could not get it passed 3700 rpm unless I was in neutral, then it was fine. but I was in the no wake zone.

Sorry for the long winded speel..............

Any Advice?????


Thanks Cactus52
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,581
Re: what do I try next ""follow up""

Run the engine off a portable tank and see if it still has the same issue.

Pour the contents of the fuel filter into a glass jar to see if you are still getting water.
 

MolsonCanadian

Petty Officer 2nd Class
Joined
Jul 9, 2010
Messages
199
Re: what do I try next ""follow up""

Check for a stuck check-valve in the line or tank. I had similar symptoms, turns out it was a $3 ballvalve sticking.
 

6meter

Chief Petty Officer
Joined
May 15, 2010
Messages
525
Re: what do I try next ""follow up""

While its running crappy, loosen your fuel fill cap. Fuel tank vent could be plugged or full of water.
 

Cactus52

Cadet
Joined
Aug 7, 2010
Messages
10
Re: what do I try next ""follow up""

Well I ran it with the gas cap off and sucked fuel out of a portable tank (5 gallon gas can). No change. I then bypassed the water separator and it ran good for a few minutes then could not hold higher rpms. Anything below 3000 is good and consistant.

I pulled the carb off and am having it rebuilt again. The first time I felt it was rushed since he took it and was back in less than an hour. So we will se what happens.

Where can I find a check valve in the system?? That would make sense but I have had everything out and no valves anywhere??

Thanks
Cactus52
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,581
Re: what do I try next ""follow up""

Where can I find a check valve in the system?? That would make sense but I have had everything out and no valves anywhere??
If you ran it on a portable tank, you were basically bypassing the check valve which is located at the output of the tank.

Curious...why would you bypass the water seperator?
 
Top