2 questions for my 5.7 EFI Alpha One...

[Steve91T]

This is a 1995 Mariah with 410 hours. (new to me).

1) Runs beautifully except it loads up during idle. Idle is like 400-500 RPM and when docking, going in and out of gear, it often quits. Had a marina look it over and and said it threw no codes, so the cleaned the air idle sensor (something like that), and it seemed to help. The boat hasn't been used much over the last couple of years. I'm thinking the TB needs to be cleaned. Any other suggestions? The marina said it just needs to be run. Once again, idle is the only issue. Other than that, it's a sweet running engine. Very smooth and about as loud as a sewing machine!

2) The steering can jam at full port lock. I was docking and the steering jammed. It didn't take much to get it unjammed, but I don't like that it did jam. It did it to me one more time while docking. I don't think it did it to the starboard side. The marina had also looked over the steering and said everything looked perfect.

And of course while docking, with a lot of people watching, the steering jammed and the engine quit at the same time. This can't happen again!

Thanks,
Steve

 

[Steve91T]

Re: 2 questions for my 5.7 EFI Alpha One...

Anyone? I've got big plans this weekend and I'd like to take care of these issues this week.

Steve

 

[lcmains1]

Re: 2 questions for my 5.7 EFI Alpha One...

What is the operating range for the RPM at idle? 4-500 seems a little low.

 

[Don S]

Re: 2 questions for my 5.7 EFI Alpha One...

The idle should be 600 rpm, and it computer controlled.

Had a marina look it over and and said it threw no codes,

This seems to be common on a lot of EFI posts. There is a LOT of things that can go wrong with the EFI system that doesn't set a code. Any shop that thinks that, shouldn't even be working on it.

IAC valve, MAP sensor, ECT sensor, to name a few could cause your problem and not set a code.

It could even be something simple like needing a full tuneup. New cap, rotor, and spark plugs. None of those items will set a code, but they will sure cause your engine to run poorly.

 

[MEATBALL0309]

Re: 2 questions for my 5.7 EFI Alpha One...

i totally agree with don here i work at a toyota dealership and see alot of different makes of cars come thru the shop with idle problems that never set a code. and if this shop just hooked it to a scan tool and looked for codes they really didn't diag. all of the iteams don listed can be monitored while running using scan tool to see if the are working properly. even a slightly clogged injector could cause this when it is idling and only supply and small amount of gas could cause it to drip instead of atomizing properly and cause a missfire. had a ford suv not to long ago had same problem.

 

[Fishermark]

Re: 2 questions for my 5.7 EFI Alpha One...

when docking, going in and out of gear, it often quits.

Have someone look at the shift interrupt switch to see if it is engaging and staying engaged too long.

Like mentioned above, it could be a tune up issue... or a lower shift cable needing to be replaced.

 

[Steve91T]

Re: 2 questions for my 5.7 EFI Alpha One...

The idle should be 600 rpm, and it computer controlled.



This seems to be common on a lot of EFI posts. There is a LOT of things that can go wrong with the EFI system that doesn't set a code. Any shop that thinks that, shouldn't even be working on it.

IAC valve, MAP sensor, ECT sensor, to name a few could cause your problem and not set a code.

It could even be something simple like needing a full tuneup. New cap, rotor, and spark plugs. None of those items will set a code, but they will sure cause your engine to run poorly.

Ok, one more question. Are these parts just chevy 350 parts? Or do I have to get marine parts? I know my 97 Camaro was running rich, couldn't figure it out. So I replaced the MAP, cheap and easy. Fixed the problem.

I'm thinking I'll do cap, rotor, plugs first, then start replacing some of those sensors.

Thanks,
Steve

 

[Steve91T]

Re: 2 questions for my 5.7 EFI Alpha One...

Have someone look at the shift interrupt switch to see if it is engaging and staying engaged too long.

Like mentioned above, it could be a tune up issue... or a lower shift cable needing to be replaced.

Thank you, but it's loading up at idle.

Steve