South Bass fish school with engine question

[wakina]

The best thing to do would be to have the codes stored in the computer read to find what is actually wrong before throwing money at it on the theory that this might be the problem or it could cause the probleml. It could be as simple as a fuel pressure regulator.

[bocajemma]

Is it a carb or fuel injected?

[wakina]

That is a 496 cid GM big block, it is almost certain that it is multiport fuel injected with a contol modual/computer. Those engines and electronics have a very sofisticated electrical system that have a large amount of sensors that must be in working order for it to run properly. Save yourself some time and money and have the codes read.

[Buc-Eye]

Def fuel injected. Thanks for the input. We just called another group in to look at it and I asked if they could put a computer on it and read the codes and they said that they would defiantly do that. We are going to have them check the fuel filters as well.

[jreed2528]

With an EFI engine that is not running right it is really hard to diagnose with out reading the faults. The EFI will try everything it can to make the engine run correctly given the information it has received from all the sensors even when a sensor is sending bogus information. I don't think you will be able to hood up a standard autozone rental OBDII code reader, rather I believe it uses a CAN bus style plug.

[wakina]

I am not sure if Volvo Penta uses the same ECM that Mercruiser uses or not, but the ones Mercruiser uses are, I think, furnished by a GM supplier to operate the engines made by the GM Powertrain Marine division which are then supplied to the different manufacturers ready to install. Most of the differences are cosmetic in nature as well as some of the accessories such as water pumps and other external engine parts.

In any event if the code check comes back negative and the ECM does not monitor fuel pressure before reaching the injector banks, then it is most likely in the fuel delivery system. Which consists of the fuel pump and the fuel pressure regulator or in some cases a second regulator when there is one on each bank of injectors and mounted on the injector rails. The engine is designed to operate on a certain amount of fuel pressure and if it is to low the engine will not operate correctly. Most of the time when the engine seems to run fine at higher RPMs and then wants to die at idle there is a fuel pressure problem which may or may not show up with a code scan. Almost all other problems will be recorded in the ECM's memory bank.

Remember this is nothing more than a standard GM engine that has been made suitable for marine use with the likes of brass soft plugs, exhaust manifolds and other superficial things that make the engine safer in a marine atmosphere as well as more corrosion proof. The parts that make it run such as fuel pressure regulators, and other sensors are the same ones available at the GM parts department and used on street vehicles! When you remove a sensor from the engine the part number stamped or molded into it or on it will most often be identical to the ones in the GM service manuals for cars and trucks at less than half the cost. Alternators, starters, coils and distributors must be spark proof to meet Coast Guard safety requirements so they are different but are available from GM suppliers and other outlets at reduced cost. In other words you are paying for the name of the engine supplier.

[fishinnotcatchin]

I do not no the first thing about motors!My Buddys boat has an older Ford motor in it.He had same issue with it loading up with gas etc. Had it worked on several times.Boat ran great when running from here to there.As soon as he tried to slow troll,is when it acted up.Couple-3 years ago he bought a smaller kicker motor for trolling.It has been the ticket!He recently purchased an extended handle(tiller?)Takes some time to get used to.But will be much more comfortable to work with on long hauls.NO mechanic here,maybe yours just needs an adjustment?Good luck with that,and the fishin!!!