Crusader 454 wonbt grab higher RPMbs

"I have a 1996 Trojan 350 Expr

"I have a 1996 Trojan 350 Express with twin Crusader 454 TBI HO 350hp engines. The engines have 400hrs. I did my winter maintenance projects recently: changed oil & filters; replaced Racor fuel filters and fuel filters at the throttle body; changed plugs, wires, distributor cap and rotor. I took the boat out for a test run after doing my maintenance and discovered that the Stbd engine would only grab about 3500 rpm's while the port engine would get 4500 rpm'd at WOT.

I thought that it might be a fuel starvation problem so I did a pressure test of the fuel system which recorded 20psi for both engines.

I never had a problem before with the engines performance. Both engines have always performed equally as well. Now I'm at a loss. What should i be looking for??"

"WE don't know, but YOU ca

"WE don't know, but YOU can find out.

Do a full throttle plug test. To wit: Run the boat wide open for 10 seconds, then IMMEDIATELY chop power to the bad engine and shut it off. (Keep the other one going to prevent a sudden stop, which can shove water up the exhaust system.)

Next comes the hard part: Remove at least 4 plugs and read their colors. White means you MIGHT have a fuel starvation problem; light to dark grey or brown means ignition problems.

Armed with this knowledge you can figure out where to look.

Jeff"

"Thanks for the input. I'd

"Thanks for the input. I'd like to save this test as a last resort. Let's say it is a fuel problem, and I've replaced the Racor and secondary filter, and tested the pressure which is good (20psi), and no error codes show up then there is only the Primary filter and the anti-siphon valve left in the fuel dilivery system. Has anyone ever seen a cloged primary filter, which is about the same mesh as my screen door, or a defective anti-siphon valve??

I might suspect a bad load of fuel but I filled both tanks at the same time fron the same fuel dock, and the Port engine runs perfect.

Do you suspect that it may be the ignition control module in the distributor? I have to believe that because it's a solid state device it would either work or not work all the time. I may be wrong. Anyway, control modules are about $90 from GM. I don't want to replace it just because.

Is there something else in the electrical system that could be suspect. Something that wouldn't show an error code and may be bad?

All comments welcome."

how about a bad plug wire. I h

how about a bad plug wire. I have had new ones out of the box that are bad. Put the old cap back on and see if that works I have had that happen also. Simply is always a good start and probably the solution.

"~)

"I've replaced all the wir

"I've replaced all the wires, cap and rotor. And had the computer diagnostic done afterwords. Wouldn't a bad wire show up as an error code? Besides, I threw out all the old stuff."

"This has got to be a simply p

"This has got to be a simply problem and computer testing is usually done on dry land. The motor ran fine last year so something you did changed that. Switch all plugs, wires, cap, and rotor to the other motor and see if the problem moves."

"We've got bad weather in

"We've got bad weather in So CAl right now. I won't be able to do anything until later this week. I will keep you posted. In the mean time if anything else pops to mind, please let me know."

If that has no change try swap

If that has no change try swaping the coil and Distributor. Also inspect both rotors and compare to make sure they are the same. Check firing order on plugs... been there done that:~)eliminate the electrical then move to fuel. Inspect fuel filter at throttle body could it be damaged or defective?

"Thanks for everyone's fee

"Thanks for everyone's feedback. I have resolved the problem. I removed the anti-siphon valve from my starboard gas tank and discovered a piece of metal shaving and a plastic shaving that had become lodged in the valve, thus preventing the valve from opening all the way.

The "Dream Weaver" now runs fine and she and I have a big smile on our faces."

So what made you check that? w

So what made you check that? was there something that made you think fuel instead or electrical.

Glad to hear the smile on your faces"~)

"Good deal. Just for the reco

"Good deal. Just for the record, performing my little test would have pin pointed the problem as fuel related, which would have pointed you in the right direction (instead of changing black boxes and etc.) And, whether you realize it or not, you were lucky not to have burnt a hole through a piston running lean like that.

Happy boating! We 'splash' in a few weeks.

Jeff"

"Yes jeff you where right and

"Yes jeff you where right and usually are!! but some people need a little extra proding, or don't want to spend the money on tools or aren't relating the problem correctly.

Should I stop giving input? I am just trying to give people a cheap way of figuring out their problems.

Paul"

"I just had a GUT feeling that

"I just had a GUT feeling that the problem was fuel. After all, I had already done a complete electrical tune up. And, I decided to investigate the problem starting at the fuel tank and work towards the engine. As luck would have it, my first stop at the anti-siphon valve uncovered the problem which was probably there for some time. I just never noticed it because I normally don't run the engines at W.O.T."

"No offense meant, Paul (t

"No offense meant, Paul (though a plug wrench isn't an expensive tool, right?)

Bob: Glad to hear your motorS (plural) are working well. Boating isn't fun when one of them is being mulish!

Jeff"

snicker snicker Thats cool Jef

snicker snicker Thats cool Jeff

"Bob,

For future refrence,

"Bob,

For future refrence, if you did your fuel pressure test at WOT you would have inentified this problem right away. Most fuel starvation problems are not evident at idle or low speeds since the fuel draw is so minimal. Also, don't expect a computer analasys to find your problems. You have a MEFI III, which is very primitave as far as diagnostics go. You will usually identify problems manually faster than the computer will tell you. It will not identify most common problems. Glad you're up and running. Rick"