chevalcabre

hello dear friends...
i am having some issues with my new ride i fell in love with.

it is a 1998 american offshore 26 with a 454 mpi /procharger.

upon cold start,everything is great.i can get a good 15 min. of strong boating with the pyrometer showing 9 and no smoke or soot coming out..

after a good strong short ride, i get a power loss and cant get passed 4000 rpm.no throttle response,or at least very weak.
engine misfires.lots of fuel being dumped and smells fuel strong,soot covers the back of the boat quickly.
i noticed today for the 2nd time that after the issue shows up, my pyrometer gage goes down to "0"...

it idles very bad...
when cold again,like the next day, boat is a #1 for the 15-20 1st minutes again.. then same thing occured.

it uduslly gets 4800-4900 rpm...and used to stay very strong during my usual 30 min. rides...

i replaced the plugs thinking they were fouled ...but today found out it did it again.

anyone have any ideas ? or anyone know these procharger systems well ?

the boost goes up to what seems like 6-7 on ythe gage.
water temp gage never seen it go past 130.
fuel pressure is approx 50 i think.
all gages seem fine all through the ride and even after the issues start..but the pyrometer just shuts down and falls to zero...
and again, lots os soot, lots of fuel smoke...running super rich from that point...

29scarab

Make sure you put this in the General Q&A section for the tech guru's. I'm sure someone will chime in and get ya some help.

chevalcabre

i took it out tonight..water was calm and even at cold start..it did the same thing. it smokes and smell terrible. idle is rough as if it is misfiring badly.
fuel pressure is at 47-50

i tried to go for ride but this time, i couldnt get it to plane there was not enough power at all. even tough i ushed the throttles, there was no power at all.

i noticed something new as well... at low rpm,1200-1500,trying to get some rpm with little throttle, i was hearing popping noises which seemed like backfiring inside under the hatch,.... not from the exhaust....non-stop little backfires..one after another...

maybe the cap is full of humidity from having washed the boat throughly ??maybe the little backfires i hear are caused the cap/rotor ...not sure...

could it be that a bad cap and rotor or one that has water

chromecat

yes...
a bad cap and rotor could cause lots of trouble... look in side the cap for any signs of cross firing...
also check your ignition for any loose wiring especially ground wires....

Don

B one

Look for chris sunkin he should be on here some where, it sounds like carbs to me find chris he will fix you up or mobileman. there not on here now check with the in the am or send them a pm.

greencard

iTrader: (2)

hook up a scan tool and see if the computer sees a correct engine temp. I have seen the computer engine temp sensor fail causing all your symptoms..(it thinks it is really cold and tries to correct by richening). good luck.

chevalcabre

news:

intercooler leaking water into intake...
that could have bent a valve or a few...
compression test tomorow will confirm.
new intercooler on the way.

i had water /air/fuel going in.. can that be th reason for the computer to send in much more fuel ? and making it very rich ?

what fuel pressure should i be at ? i read between 40/50

chevalcabre

good compression all over.
one spark plug had no gap at all...these were installed new last week... maybe the mechanic did not realise .
that is probably why i had the popping noises in the intake , i hope.

i was worried the valves could have gotten bent from water and that the combustion was kicking back through the intake and made the popping noises... must be the spark problem with that plug....

once i get the new intercooler, i will be able to test all of that again.

berryo

I had the same problem with my intercooler leaking, but the mechanic noticed it when tuning the motor up. Supposedly Procharger intercoolers are known for this!

chevalcabre

i also heard the same !

at least today, we found out the boat has no errors on the computer scan...

so between the bad plug gap and the bad intercooler that was leaking some water, i hope to see that everythong gets back in order ...

what engine do u have and what fuel pressure are u seeing ?