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!

Limp mode 99ss lxi


Recommended Posts

Hi all, 
My '99 sunsetter lxi seemed to be on limp mode last night. I wouldn't go over 3,000 rpm in gear, but when I reved the engine out of gear I got more rpms out of the engine. 
I read a few posts about limp mode but not quite sure where to start. I just filled it up with fresh supreme fuel. Never had this issue before. Thanks for for the help!

Edited by pmm009
Typo
Link to post
1 hour ago, pmm009 said:

Hi all, 
My '99 sunsetter lxi seemed to be on limp mode last night. I wouldn't go over 2,000 rpm in gear, but when I reved the engine out of gear I got more rpms out of the engine. 
I read a few posts about limp mode but not quite sure where to start. I just filled it up with fresh supreme fuel. Never had this issue before. Thanks for for the help!

I could be wrong, but I don't think any 1999 engine has a limp mode.

What engine do you have?  Diagnosis will depend on a few details.

Link to post
2 hours ago, justgary said:

I could be wrong, but I don't think any 1999 engine has a limp mode.

What engine do you have?  Diagnosis will depend on a few details.

Indmar 325 5.7L

Link to post
50 minutes ago, pmm009 said:

Indmar 325 5.7L

Multi port injected?  First do a full tune up if you haven't done one in a while.

Next, test the fuel pressure at key on, idle, and wide open throttle.  They should all be the same ~42-44 PSI.

Link to post
BlindSquirrel
4 hours ago, justgary said:

I could be wrong, but I don't think any 1999 engine has a limp mode.

 

My 1998 went into what I believe was limp mode, once, when it was over heating because of an impeller failure. I don't remember the RPM limit, but it was well under 3,000. Wife was driving and didn't notice the temp gauge or check engine light. Went to take off from a very long no wake zone, and it didn't want to go much over 10mph or so. 

Link to post
3 minutes ago, BlindSquirrel said:

My 1998 went into what I believe was limp mode, once, when it was over heating because of an impeller failure. I don't remember the RPM limit, but it was well under 3,000. Wife was driving and didn't notice the temp gauge or check engine light. Went to take off from a very long no wake zone, and it didn't want to go much over 10mph or so. 

You could be right about that one, or maybe the pistons just fit too tight when it got hot.

Link to post
20 hours ago, justgary said:

Multi port injected?  First do a full tune up if you haven't done one in a while.

Next, test the fuel pressure at key on, idle, and wide open throttle.  They should all be the same ~42-44 PSI.

It's the EFI engine. I've noticed when I "key on" that the gauges have more trouble coming to life. They are slow to light up, maybe a symptom of low fuel pressure? 

Link to post

 

On 7/18/2021 at 10:30 AM, justgary said:

I could be wrong, but I don't think any 1999 engine has a limp mode.

What engine do you have?  Diagnosis will depend on a few details.

22 hours ago, pmm009 said:

Indmar 325 5.7L

The owner's manual refers to it as "power reduction mode." 

Link to post
20 minutes ago, pmm009 said:

It's the EFI engine. I've noticed when I "key on" that the gauges have more trouble coming to life. They are slow to light up, maybe a symptom of low fuel pressure? 

Slow dash gauges are independent of fuel pressure. 

Link to post
22 hours ago, justgary said:

test the fuel pressure at key on, idle, and wide open throttle.  They should all be the same ~42-44 PSI.

How are those fuel pressures looking?

Link to post
1 hour ago, xav8rdtc said:

How are those fuel pressures looking?

It's going to have to wait until next weekend when I am back at the cottage. I am planning on testing the fuel pressure, should I also try testing the oil pressure? Or is there another test I should do to help narrow down the problem? 

Link to post
3 hours ago, pmm009 said:

It's the EFI engine. I've noticed when I "key on" that the gauges have more trouble coming to life. They are slow to light up, maybe a symptom of low fuel pressure? 

More like low voltage to the dash.  What is your indicated voltage?  What did the engine temp look like when this happened?  No beeping from the dash?

Definitely check your fuel pressure but if it hasn't been done lately I'd change the following as part of a normal tune up and preventive maintenance:

  • Spark plugs (should be done every 2-3 years)
  • Cap & rotor (get the marine version)
  • Spark plug wires (they change resistance when they age)
  • Coil (older units can soft or hard fail when it gets hot)
Link to post
7 hours ago, pmm009 said:

It's the EFI engine. I've noticed when I "key on" that the gauges have more trouble coming to life. They are slow to light up, maybe a symptom of low fuel pressure? 

The gauges will rattle around for about a second or two to calibrate themselves when they power up.  If that is what you are seeing, it is normal.  Otherwise, clean all of your power connections.

Link to post
22 hours ago, formulaben said:

More like low voltage to the dash.  What is your indicated voltage?  What did the engine temp look like when this happened?  No beeping from the dash?

Definitely check your fuel pressure but if it hasn't been done lately I'd change the following as part of a normal tune up and preventive maintenance:

  • Spark plugs (should be done every 2-3 years)
  • Cap & rotor (get the marine version)
  • Spark plug wires (they change resistance when they age)
  • Coil (older units can soft or hard fail when it gets hot)

I left my blower on for a few hours which probably weakened the battery. Do you think there is a correlation with the weak battery and limp mode? 

Link to post
  • 1 month later...

Here is the update from my limp mode I experienced. I did 3 things with a total cost of about $75 CAD: 

1. Changed the fuel filter. Napa Part #: NGF 3481 

2. Changed the spark plugs. Part #: ACD MR43LTS gapped at 0.045

3. Put a fuel system cleaner in the tank. STP Ultra Fuel System Cleaner (I used half the bottle as instructed). 

So far the engine is running like a charm, I can't believe what a difference the new spark plugs make. Hole shot when skiing is the most explosive I've ever experienced! The engine is running smooth, doesn't force, hesitate or misfire (I didn't realize that's what was happening with the old spark plugs) also the vibrations that I was experiencing before have gone away (likely the misfiring). 

Any other recommendations for routing maintenance that can make a difference? (Oil change and impeller are new from this season). Cheers! 

  • Like 2
Link to post

I wouldn't hurt to clean the inside of the throttle body with a can of carb spray.  Open the throttle so you can get all of the fun parts inside.

I also like to spray the entire engine with light spray oil every few months.  I do everything from the oil pan and motor mounts up to the throttle body except the belts and pulleys.  This helps keep corrosion away from sensor and ground connections as well as making the whole thing cleaner looking.

About once every few years I shoot the engine with a strong stream from a garden hose (avoid the throttle body) to get the crud off, then crank it and let it warm up and to sling excess water from the rotating parts.  After it is dry I start the oil spray routine again.

Edit:  I forgot to mention a light oil spray on the power bus bars under the dash.  Keeping oxygen away is a great way to avoid corrosion.

Edited by justgary
Link to post
On 8/29/2021 at 11:16 AM, justgary said:

I wouldn't hurt to clean the inside of the throttle body with a can of carb spray.  Open the throttle so you can get all of the fun parts inside.

I also like to spray the entire engine with light spray oil every few months.  I do everything from the oil pan and motor mounts up to the throttle body except the belts and pulleys.  This helps keep corrosion away from sensor and ground connections as well as making the whole thing cleaner looking.

About once every few years I shoot the engine with a strong stream from a garden hose (avoid the throttle body) to get the crud off, then crank it and let it warm up and to sling excess water from the rotating parts.  After it is dry I start the oil spray routine again.

Edit:  I forgot to mention a light oil spray on the power bus bars under the dash.  Keeping oxygen away is a great way to avoid corrosion.

Which carb cleaner do you recommend? I was thinking of using CRC throttle body and air intake cleaner since my engine is EFI. 

Link to post
1 hour ago, pmm009 said:

Which carb cleaner do you recommend? I was thinking of using CRC throttle body and air intake cleaner since my engine is EFI. 

Since we aren't talking about an engine with cats, I would buy whichever product the box store or wally world has for the lowest price per ounce.  They all seem similar to me.

Link to post
  • 2 weeks later...

I noticed a small oil leak coming from one of the red boots where the oil filter is located. I think the wire/boot might need replacing but not sure what the part is called. I also noticed a little bit of what looks like oil on the surface of the water when I dock the boat. I am hoping they are related. Here are some pictures for reference. https://photos.app.goo.gl/C8zjN8NqvmEJvyof7 

Link to post

That oil is probably runoff from above.  Maybe the valve cover gasket is leaking.  Degrease the engine and then inspect it every outing to find the source.

Your plug wires seem original, but maybe someone actually replaced them with OEM wires.  In any case, they could be part of your performance problem.

Link to post
4 minutes ago, justgary said:

That oil is probably runoff from above.  Maybe the valve cover gasket is leaking.  Degrease the engine and then inspect it every outing to find the source.

Your plug wires seem original, but maybe someone actually replaced them with OEM wires.  In any case, they could be part of your performance problem.

Thanks, I'll do a more thorough inspection once I clean things up. I am planning on changing the spark plug wires for next season. The engine is still running better than ever since I change the spark plugs, but I am sure a few more improvements (new wires for example) will make it even better.  

Link to post

Join the conversation

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

Guest
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...