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View Full Version : '87 PS190 Loss of RPM's after warm up


getoutside2play
06-23-2011, 08:48 PM
The engine only has about 600hrs on it.

After a minute or so at full throttle my RPM's drop from about 4800 to 3k or so and bounces around between the two (it seems to be missing). It starts and idles perfectly even after it's warm. The problem started just once in a while and now it is every time (progressed in probably 5-6 sessions). There are no knocks or other obvious problems.

So far I have:
*Replaced distributor cap and rotor
*Replaced spark plugs
*Replaced spark plug cables
*Put dry-gas in

The oil looks clear (no water)

I know this sounds a lot like other problems covered in the forum, but I am not sure the next step.

Also, I put an EI in about 8 yrs ago. Could that need replacing?

I had an impeller explode on me this season. I don't think the two are related, but I am at a loss. The engine never got over 205 degrees. I replaced it and had the old pieces plug up the intake on a hose I had already cleared. But, I was carefully watching the temp gauge and again stopped before it got too hot.

Thanks for any suggestions.

1redTA
06-23-2011, 08:52 PM
ignition coil?

blasko
06-23-2011, 09:25 PM
I had the same problem on my 1988.

The check valve on the top of the fuel tank would only partialy open,resulting in fuel starvation. Remove and try.

Kevin 89MC
06-24-2011, 09:57 AM
When was the last time you replaced your fuel filter & fuel/water separator? If it's been more than a few years, replace them. I had a high speed stall in corners, and new filters cured it. It is relatively easy & cheap, ~$10 for the fuel filter and ~$30 for hte water/fuel separator. Get them from Skidim or your local dealer. Also as Blasko said check your tank check valve. A bit harder to get to (on top of your tank), but they can plug too. Mine broke when trying to separate, fortunately my local dealer had one in stock.
Good luck,
Kevin

getoutside2play
06-24-2011, 12:14 PM
Thanks for the suggestions. Originally I was convinced it was electrical, but now I am leaning more toward fuel.

I ran it without the fuel cap and it still is bogging down so I don't think it is being starved that way.

I haven't replaced the fuel filter or separator in 10yrs so that will be next on my list. I will also ask the dealer about an ignition coil.

I hope it isn't a bad gas issue as that would be a huge pain. Although, I am slowly burning through what's in the tank. If the issue keeps dogging me I may burn through the whole tank trying to figure it out anyway.

getoutside2play
06-24-2011, 05:23 PM
I replaced the fuel filter but the dealer didn't have a separator. The old one had some rust in the bottom and the seal was rotten. It came out in a couple pieces and the outer ring was rolled up in the flange. The new seal seemed a little big and wasn't a great fit, but I think I finally got it and confirmed it is not leaking gas.

I also added a couple cans of SeaFoam to the gas.

It ran great for about 3 minutes before bogging down again.

I tried to replace the coil but need some help with hooking it up. The old one was not marked with a pos or neg, only a "bat". This side had an orange wire coming from it. The other side has 2 grey wires, one leading to the distributor. Can anyone confirm the pos and neg for me on the old coil?

Thanks again for the help.

getoutside2play
06-25-2011, 01:56 PM
Update:

Hooked up coil.

Drained and replaced gas. The old gas was cloudy and had a couple tablespoons of water in it.

Now, it idles OK. But stalls when I put it in gear and whenever I get into the 4 barrel of the carb, it bogs down. So, I can slowly accelerate up to 3k rpms and it runs perfect. But, if I gun it, or try to run full throttle, it bogs.

Looking like a carburetor plug?????

I can't understand why last night it would run perfect at 4800rpms and bog only after running a couple minutes. I changed gas and put a new coil on it, and now it is behaving differently??????

It's confusing because at times it behaves like an electrical issue and other times a fuel one.

ARGGHHHHH!!!!!!!!:mad:

getoutside2play
06-26-2011, 10:42 PM
Today I drained the fuel/water separator and replaced the fuel filter (again) thinking I still may be chasing down issues from old/bad gas.

Now, it runs up to 4100rpms before bogging down.

I am confused by the changing symptoms, but maybe that means something to someone smarter than I am?

I've tried to work on and replace one thing at a time so I could isolate the problem. However, the inconsistency with the way it is running is throwing me for a loop.

Any suggestions?????

getoutside2play
07-01-2011, 08:51 PM
I finally got and installed the new fuel/water separator. The engine started up and idled for about 20 seconds before completely dying. I checked the canister and added more gas to the assembly as it seemed the new filter soaked up a lot of gas. I tried getting it to restart unsuccessfully using starting fluid. It definitely is starved for gas. I am thinking it is the fuel pump now?

Are the lack of responses because I am obviously a novice mechanic, or is this one of those difficult issues that I should really just take it to the dealer to fix?

Cloaked
07-01-2011, 09:33 PM
I finally got and installed the new fuel/water separator. The engine started up and idled for about 20 seconds before completely dying. I checked the canister and added more gas to the assembly as it seemed the new filter soaked up a lot of gas. I tried getting it to restart unsuccessfully using starting fluid. It definitely is starved for gas. I am thinking it is the fuel pump now?

Are the lack of responses because I am obviously a novice mechanic, or is this one of those difficult issues that I should really just take it to the dealer to fix?Lift your air cleaner from the carb and see if you are getting steady fuel pumped into the carb. The choke should be open (electric choke) and you should be able to see fuel as you pump the throttle (pull the knob and use the reverse position and motion for the throttle).

My preference is to not use a starting fluid. I have primed the carb through the open carb port with a small amount of fuel but that is not safe in the event of a backfire.............but I have done it as a primer, then replace the cleaner back on and try to fire it up.

It's hard to justify the trial and error method of repair because that usually becomes a nickel and dime methodology. However a new fuel pump is always in order if you have not put one on in several years. I have seen them last a long time but eventually the mechanical pump will need replacing. I always keep a spare fuel pump in the garage. They always die on a four-day holiday weekend with none available until the internet shops open on day five.... Don't ask me how I know that...

There is always the temptation to remove the hard fuel line between the pump and the carb to see if the pump is putting out. I have done this but I have also most always had issues with either threads not aligning back up, crossing threads upon reinstallation, or fuel leaks after one thinks the line is tight. Over the years, I try to leave that conection alone as long as I can.

If you can justify a new pump as a necessity (preventative maintenance) as well as a remedy, then so beit.

If you are getting fuel into the carb upon pumping the throttle (backward motion) then the pump is putting fuel into the fuel bowl (up to the point of the bowl running empty........or not). At that time, you may have a spark issue (coil, distributor area, or other electric issue). The springs in the bottom of the distributor can also go weak or break, but I have not seen that as a frequent event, however it's possible. I would not see a need to replace the EI kit at this time.

The carb could be gummed up from poor storage procedures (no Sta-Bil) or it could need rebuilding with a kit (due to dry gaskets sucking air or a shot power valve). One of the steps in the rebuild procedure is to soak the carb overnight, to clean the tiny ports inside of the body.

One thing I'd be inclined to do to cut through the chase is loosen the fuel line on top of the pump (no need to remove). Pull the coil wire from the coil, then turn the engine over a few times (nothing hard) to see if the fuel line leaks fuel upon cranking. If it does, your pump is probably good (no guarantees). Then go from there, suspecting spark issues or a carb needing a rebuild. Just pot shots here so don't quote me in court. Patience..... don't get frustrated.

Rebuilds are easy with a good set of instructions. The instructions in the kits suck but I have good instructions in PPT or I think Holley's web site has the procedure documented.

I suspect the fuel pump if you're still using the original. And if that is the case, a new pump will not hurt, regardless if that is the issue or not.

.

getoutside2play
07-02-2011, 08:53 AM
Thank you very much for the detailed response.

I guess I should consider myself lucky because I haven't done anything to the engine (other than routine maintenance) in 10 yrs. I figure most of these parts are due for replacing.

Also, I have been relying on the dealer for advice. I think it is good business practice for them to keep me trying new parts;)

I will check the fuel today per your advice and get a new pump as it is the original.

Have a great holiday weekend!

hkallestad
07-05-2011, 04:12 AM
Changing the two fuel filters is routine maintenance;-)) I change them once a year. Hope you fix your problem.

getoutside2play
07-11-2011, 09:59 PM
Thanks to everyone for the help.

I ended up replacing the fuel pump, and all the filters. I also replaced the fuel line going into the tank because, like everything else I tried to check, it was corroded and broke when I tried to remove it.

Cloaked, I hear you on the hard fuel line. The new fuel pump was a little different so I had to push on it to get it to attach. That wasn't a big problem, but when I replaced the carb, it started leaking. It needs to be replaced.

After all that, the same behavior. So, I had the carb rebuilt and now it actually runs worse. It will idle but dies under any load. I have to trust the carb was done right, but I don't know why it runs worse. To me, it indicates the issue may be with the carb.

Anyway, summer is half over and I am done messing with it. Every time I need a part, I have to drive 45 minutes or wait a few days for shipping. So, off to the marina tomorrow. I will let you all know what they do and find.:(

Thanks again.

mastercraft-4-life
07-11-2011, 10:53 PM
i am having just about the same problem you are having. i have a 1985 stars and stripes. ford 351 w.(I= me and my mechanic) i pulled the tank cleaned it. changed fuel lines. changed fuel water seperator. i dont thing i have a fuel filter. (i cant find it) unless its in the tank. pulled the carb pulled it apart, it looked good. plugs are good. now we are looking in the the distributer.

mastercraft-4-life
07-12-2011, 01:49 AM
And yes please let me know I'm chasing the same type of thing.if you can message me and let me know what you find that would be great.

TLR67
07-12-2011, 07:42 AM
Thanks for the suggestions. Originally I was convinced it was electrical, but now I am leaning more toward fuel.

I ran it without the fuel cap and it still is bogging down so I don't think it is being starved that way.I haven't replaced the fuel filter or separator in 10yrs so that will be next on my list. I will also ask the dealer about an ignition coil.

I hope it isn't a bad gas issue as that would be a huge pain. Although, I am slowly burning through what's in the tank. If the issue keeps dogging me I may burn through the whole tank trying to figure it out anyway.

That wont do anything... The line coming from the tank to the seperator has a fitting with a ball bearing and spring in it that sits on top of the tank.. Take the line off it and remove it... I guarantee thats the issue...... I just troubleshooted to the moon to find this hung up on mine... Damned coast guard regulations...

TLR67
07-12-2011, 07:43 AM
i am having just about the same problem you are having. i have a 1985 stars and stripes. ford 351 w.(I= me and my mechanic) i pulled the tank cleaned it. changed fuel lines. changed fuel water seperator. i dont thing i have a fuel filter. (i cant find it) unless its in the tank. pulled the carb pulled it apart, it looked good. plugs are good. now we are looking in the the distributer.

Remove the fitting from the tank that the line goes on and check the bearing and spring...

getoutside2play
07-12-2011, 08:50 AM
Remove the fitting from the tank that the line goes on and check the bearing and spring...

I wish that was it!!! I removed the fitting you are referring to and it broke. I replaced everything without the ball-bearing check-valve and still had issues.

When I posted about the fuel cap, I was confused as to the location of the valve (I was thinking overflow). I could see how this is a common problem and the dealer said they knock the bearing out frequently on older boats to fix issues like mine.

I will let you know what the dealer does.

Hawksinkalispell
07-12-2011, 03:44 PM
I'm chasing the same issues, 1989 Tristar with a 351, replaced:
Points and condenser for Electronic Ignition, Rebuilt Holley 4160, New cap, rotor, fuel filter (on the Fuel Pump) and changed the fuel water seperator. New Ignition coil.

Still lack of top end and lacking power, maybe that the secondaries are not opening, but it's tough to look at those while I'm driving...

Hawksinkalispell
07-12-2011, 03:47 PM
I took mine in too and one of the things the guy said is sometimes the fuel lines are sluffing thier inner line and causing a restriction, probably a good idea to change as they have got to be pretty inexpensive for 6 to 10 feet of 3/8 (or whatever) fuel line.

I also check my Check Valve and it seemed to operate just fine.

mastercraft-4-life
07-12-2011, 08:15 PM
10 ft was 12-13 dollars.

loeweb
07-14-2011, 09:02 AM
Any updates on this thread. I've been following very closely as I am having exactly the same issues on an 88 190. Boat runs great at all levels; idle, hole shot and even top end for a little while. I'm awaiting changing the fuel pump. If that doesn't do the trick I think I'll look for a check valve to replace.

Hawksinkalispell
07-14-2011, 11:12 AM
Mine's still in line at the shop, once I get word I will pass it along.

getoutside2play
07-14-2011, 03:34 PM
Mine is at the shop as well. They said they wouldn't be able to get to it until Monday at the earliest.

They have "helped" me troubleshoot up to this point and I asked that they tell me what they do and find. I want to learn and will pass it on.

Hawksinkalispell
07-20-2011, 10:18 AM
Got mine back from the shop. They fine tuned the timing a little under load, thier right by a lake so that makes it easier. I got it back last weekend and took it out for three days. Ran well, then on the final day the secondary float stuck and was dumping fuel into the secondary barrels via the overflow tube. Pulled the carb when I got home and just pulled the back (secondary fuel bowl) sprayed the neddle and seat after removing them and tweaked the float slightly to lower it.

I just rebuilt the carb last year, but maybe sitting gummed/varnished those parts enough to where they weren't working properly, and we haven't been enjoying much boating weather or time this summer, yet.

I'm supspecting that some of my issues were with that secondary float sticking open or closed, so hopefully we will be tip top next run around.

My mechanic also said that sometimes the harmonic balancer will creep and therefore the timing marks can creep to, first time I have heard that but makes some sense.

I also changed my prop last year for 4 blade which is smoother but I think maybe stealing some top end RPM's. Switching back for this weekend will post after some lake time.

getoutside2play
07-21-2011, 12:57 PM
Glad to hear you are out on the water again. That's too bad it still isn't running perfectly.

I don't have mine back yet and when I called they hadn't even had a chance to get to it (10 days after I dropped it off).

Summer is almost over and I haven't made a single ski run. More importantly, I was hoping to get my 7yr old daughter out there ripping it up too this year. :(:(:(

It's been 90+, insanely hot and humid, and it's killing me not to be out in the boat.:mad:

Hawksinkalispell
07-23-2011, 12:02 PM
Long shop wait times are the norm and very frustrating which is why this is such an active post/website for me.

We're heading out tonight hopefully all is well.

getoutside2play
07-28-2011, 10:31 PM
Long shop times and lots of $$$$$$$:(

I finally got it back yesterday. I haven't had a chance to really run it, but it seems to be fixed based on a quick hot lap.

They ended up finding a wire from the ignition switch to the kill switch had been spliced in with 18 gauge wire. Apparently a rig job from the previous owner. It's been running great like this for 14 or so years. This season, it worked it's way loose or corroded and was causing me all the goofy problems.

$300 in labor and a $.25 worth of wire and I am back on the lake.

I am not sure this helps a lot of you with similar symptoms. Unfortunately I don't feel great about my repair experience. I don't think I would have ever figured out this problem so I am grateful to the shop. At the same time, I invested a lot of time and money in diagnosing and trying to fix the problem myself. I am frustrated because I was unsuccessful and ended up paying $ and being without the boat for a couple more weeks anyway. Maybe the professional mechanics out there can point out where I went wrong in my repair strategy?

Anyway, thanks to everyone for their help. At least I have my boat back:)

thatsmrmastercraft
07-28-2011, 11:04 PM
Long shop times and lots of $$$$$$$:(

I finally got it back yesterday. I haven't had a chance to really run it, but it seems to be fixed based on a quick hot lap.

They ended up finding a wire from the ignition switch to the kill switch had been spliced in with 18 gauge wire. Apparently a rig job from the previous owner. It's been running great like this for 14 or so years. This season, it worked it's way loose or corroded and was causing me all the goofy problems.

$300 in labor and a $.25 worth of wire and I am back on the lake.

I am not sure this helps a lot of you with similar symptoms. Unfortunately I don't feel great about my repair experience. I don't think I would have ever figured out this problem so I am grateful to the shop. At the same time, I invested a lot of time and money in diagnosing and trying to fix the problem myself. I am frustrated because I was unsuccessful and ended up paying $ and being without the boat for a couple more weeks anyway. Maybe the professional mechanics out there can point out where I went wrong in my repair strategy?

Anyway, thanks to everyone for their help. At least I have my boat back:)

I just rear your whole thread (whew!) and feel your pain. Finding an intermittent problem like that can be virtually impossible. Good for your dealer to finally come up with the bad wiring. Sometimes you stumble across the solution right away.....other times you can spend a lot of time searching. I don't know what you would have done differently to find this problem earlier. Kill switches all eventually fail but one doesn't always suspect the wiring to it. On the bright side, you have replaced a lot of the wear items that slowly fail, so you should be relatively trouble free for some time unless there is more mystery wiring issues.

Hawksinkalispell
08-02-2011, 10:10 AM
I'm spouting the power of Purple power cleaner. Mine is running great now after the majority of all you went through and then the final simple thing of cleaning the Spark arrester. I read another post about Purple power used to clean the spark arrester and remember that I had an old Van that I didn't change the air filter for awhile and it started running horribly.

So I soaked the Spark arrester in some Purple power I had in the Garage and a bunch of grime came out, rinsed it with water and blew it dry with compressed air. Now it's running great, idling fantastically. The spark arrester didn't look that bad but the purple power gets places you can't see is easier and cheaper to use then carb cleaner etc.

getoutside2play
08-05-2011, 11:34 PM
The saga continues.

I used the boat twice with the kids (read: not all out on the throttle), but it ran fantastic for several hours. The one time I maxed it, I hit 5100 rpm which is higher than the 4800 that I usually had when it was running good.

Then, I took the big boys out last night. After about 15 minutes, it started acting goofy again. At high RPM it started bogging down. The longer we ran, the worse it seemed to behave. After an hour and a half, it didn't like to restart and was dying shifting out of idle. It ran OK once we got someone up as long as it wasn't full throttle so we made the most of the night.

The worst part is, the extended family had rented a house on a lake 6hrs from here all next week. I was supposed to provide the lake entertainment leaving tomorrow morning. Now, the damn thing is back in the shop and 20 of us are mastercraft-less for the week.

I wish I could afford a new one.