boat automatically slowing down?

[DAFF]

Thought the engine was more basic than what it actually is... In that case please give us a little more info on the engine size brand and fuel delivery type...

With a more computer operated engine grounds are important but more than likely it is a sensor/computer glitch.

Is there a way to check for codes???

[jsmilez]

Yea there wires everywhere! Haha but today I went out and the boat was automatically shutting down " limp mode" about every 1/2 mile we would sit for about a minute then she would take back off so me and buddies started looking at the engine and block we saw a wire going into a metal plug towards the top front right side into the motor. We unplugged it and she ran fine.. With the plug not connected the boat didn't want to start, but once we plugged it back in it would start up. we monitored the temp gauge and it never got over 170 while running. We wake boarded for a couple hours and all was well... I'm thinking it might be a bad sensor.... If indeed that was the sensor we pulled out.

My motor is an indmar assault PCM... I think is a 350 chevy or 351 ford ( again I'm a big amateur) and it's electric fuel injected... Hope this helps

[jsandy]

Ok so were do you get that it is an Indmar Assault PCM? because Indmar and PCM are two different motors. It is a 350 Indmar btw. PCM motors were not available by supra in 2000. Take it to your local Supra dealer, they can hook it up to a computer and tell you exactly what is going on. There is no point in guessing what it is and randomly pulling connections when you dont know what your doing and it is so easy to get help.

[jsmilez]

Thanks... but once again I'm 26 never been much on engines and I'm trying to learn as I go... There is a problem though the closest dealer is about 3hrs away... Can it be hooked up to any computer or does it have to be a specific type?

[Seabeejamie]

LOL...welcome to the boating world.
The computer on a boat uses MEFI, does not work with OBD (automotive) type scanners. kills me, as I own 2 VERY good scanners and can't use them on the boat. 3 hours away? may want to try fixing the easy stuff first. Again, check for corrosion and grounding problems. If your water temp sensor is working at all, you can write that one off. top right side sounds like MAP sensor...can you take a picture? this IS an automotive sensor, shoud cost about 30 dollars, which is a lot cheaper than 3 hours of hauling. for your engine, 1998 camaro 5.7 parts should fit. always take the part with you to the automotive store because electronic sensors are not returnable. The fact that unplugging it and plugging it back in allows it to run the rest of the day really sounds to me like a corrosion problem. Get some contact cleaner and dielectric grease, clean EVERY sensor connector, again looking for corrosion and bad connections. make sure the previous owner grounded the stereo system straight to the battery and not to the engine block. Same with the power wires, should not be tied to starter (this would be more difficult but I ahve seen crazier). those 2 ground wires that are supposed to be on the bolt connecting the transmission to the engine really need to be there, you ahve the same engine as me, I'll look tommorrow to see where the other end is.

[jsandy]

1998 camaro is an LS1 it is not like the motor in your boat at all. i repeat NOT AT ALL! your is either an LT1 or vortec based GM motor. again 3 hours is a long way but how many hours have you waseted so far? Do it right do it once.

[Seabeejamie]

no, it's not the same motor, you are right. Mine is a 2002, indmar assault (350), same as his, and 1998 Camaro 5.7 is exactly the same as far as cap, rotor, map sensor, tps, iac, etc. makes it much easier to get parts when you give them 1998 Camaro!

[Tim405]

Check not only the MAP sensor but also there should be 3 relays that govern the ECM. sometimes it's as easy as swapping a relay out. If the ECM detects anything improper - low oil press, temp etc... it'll go into limp. If none of those conditions exist it's usually a bad relay giving the ECM bad info. 20 bucks - 30 seconds to swap. Check the relays first - then move downstream to sensors ( cheapest to costliest) and you should be able to bird dog it fairly easily.

http://sdparts.com/details/gm-perfor...parts/12499120

If this is your motor - you can get a code reader and book from Scoggins Dickey also - it's a blink type reader. - This engine was developed by GM and Indmar in the mid 90's then around 03' GM started selling it as a crate engine. The old Legacy I owned had it - and I bought one in 09' for a little pickup I own. I think Indmar only offered it as a powerplant for a couple of years. Had the same issues with the one in the truck as you are describing. Relay fixed it! - but I have an advantage possessing the code reader and the Ramjet tech manual.

[jsandy]

i'm not sure what auto parts store you go to but the 98-02 camaro is an LS1 (347 cubic in) it did not have a cap and rotor or a distributor for that matter the LS1 has 8 indiviual coils. look it up. A v8 camaro has'nt had a distributor since 1992. 1993-97 had optispark a different animal all together

this is my 99 camaros LS1 nothing like the Indmar assault 325 that is based of the 96-03Vortec headed chevy motor.

[Seabeejamie]

LOL...I see where the confusion is now.

What I did was took the part number off the sensor directly....

GMRLS1IAC

Which I found here....

http://www.nookandtranny.com/mm5/mer...y_Code=SENSORS

I know it's not an LS1, but for my engine a lot of the sensors trade straight over. The IAC, the MAP, the knock sensor, etc. When trying to amtch them up at the time, I just found it easier to ask for 98 camaro....

I used the IAC part number because that ended up being the part that fixed it... I had never seen one go bad, but talk about an expensive trouble! burned 3/4 tank of gas getting to the launch ramp...(about 6 miles)