Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

engine lag

Recommended Posts

have a 1999 malibu response 5.7 efi. Had m.a.p. sensor changed by boat shop after they water tested boat. They say they found 2 codes, one for the m.a.p. and one for the engine temp? sensor. They subsequently told me the engine temp sensor was internal in the computer so that wasn't the problem. They put new M.a.p. sensor in...same problem if not worse. Looking for answers. The boat runs fine at full throttle, but when you pull a skier at a constant rpm..such as 2400-2800 approx., the engine lags and you have to pump the throttle to get the speed to stay the same and you get chewed out by the skier quite often...not fun. boat shop says that they checked the throttle position sensor but i wonder? All fuel filters changed..good gas in tank, low hours on boat. Motorheads to the rescue

(i hope).

Link to comment

I assume you are actually pulling a skier at 24-28 mph, is that correct? A few things I would check but the fact that WOT is okay would indicate these are not the issues: make sure the spark arrestor is clean, ensure the fuel tank vent is clear and functional. I would make sure all the throttle linkage components are in proper working order.

Link to comment

I think we need more details. Is it a Merc or Indmar or a remanuf. motor?

At what speed does it start holding? It holds at WOT, does it hold just under WOT?

At wakeboard speed ~20?

At barefoot speed ~38?

If you're pulling a skier and it starts dropping, how far does it drop? and then what happens?

If a new MAP sensor made it worse, maybe it is the problem, or the MAP wiring is shorting out.

A throttle pos. sender is only on throttle by wire?? isn't it??.

When were the fule filters last changed?

If nothing helps, run the fuel line out of a can of clean gas to make sure you're not picking up debris from the tank.

Take it to a certified Indmar or Merc shop.

Link to comment

have a 1999 malibu response 5.7 efi. ...They subsequently told me the engine temp sensor was internal in the computer so that wasn't the problem.....

Not real sure what the mechanic meant by this, but if you have the Indmar engine, 1999 EFI, Monsoon, then you in fact have 2 temp sensors on the engine itself. One feeds info to the ECM, the other feeds the dash gauge.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...