Replace IAC 2005 Mercruiser 5.0 MPI
- Thread starter GregR
- Start date
Yes , that's about all it entails. Very simple. Except the 2 times I've replaced IAC's,.... I removed the old one 1st .
Just don't let curiosity get the best of you and try to move the pintle in or out as that can make the "getting-to-know-you" learning period when the ECC/ECM checks the response to it's electrical inputs.
Mercs ...may... have an IAC foam "muffler" in the throttle body that could use cleaning and re-installation too.
Just don't let curiosity get the best of you and try to move the pintle in or out as that can make the "getting-to-know-you" learning period when the ECC/ECM checks the response to it's electrical inputs.
Mercs ...may... have an IAC foam "muffler" in the throttle body that could use cleaning and re-installation too.
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What Sandy said. Very easy.
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Check auto parts store, same part; half the price. It's really a GM part, not a Mercruiser. I did that when I needed one for my previous boat with a 5.0 Mercruiser. Installation is easy. Run engine through its paces (idle to 1000 and then back) to let the computer learn the new part. Hy
I replaced both IACs this weekend. I did not realize there was a top and bottom half, bottom half is connected to two hoses. The parts shipped to me were the top halves. The new IACS had a spring in them that my engines did not have. I replaced them both.
The port engine was still difficult to start, even back fired. I had to push it to WOT for it to start. Once warm it starts and idles fine. Starboard engine started fine, which is normal, surged for a bit and then idled fine.
We went for a 2 hour cruise. As I was coming off plane the starboard engine shut down. It starts up fine, though when I put it in gear the engine shuts off. I tried many tricks but no matter what I did as soon as I put it in gear it shut off.
Could this be related to the new IAC? Perhaps it's not the right one with the spring in it? Part #s match up.
Previous work done by the marina to resolve idling issue with both engines includes new spark plugs both engines, cleaned the fuel pressure regulator on starboard engine.
The port engine was still difficult to start, even back fired. I had to push it to WOT for it to start. Once warm it starts and idles fine. Starboard engine started fine, which is normal, surged for a bit and then idled fine.
We went for a 2 hour cruise. As I was coming off plane the starboard engine shut down. It starts up fine, though when I put it in gear the engine shuts off. I tried many tricks but no matter what I did as soon as I put it in gear it shut off.
Could this be related to the new IAC? Perhaps it's not the right one with the spring in it? Part #s match up.
Previous work done by the marina to resolve idling issue with both engines includes new spark plugs both engines, cleaned the fuel pressure regulator on starboard engine.
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Yes the IAC or Idle Air Control Module allows the engine to operate properly when coming off of cruise and going to slow or idle. Replaced a few of then on my 8.1's along with the little piece of foam in the throttle body. It's listed as a muffler and costs about a dollar. The foam gets brittle and breaks off in pieces and jams the valve in the IAC. The foam should be changed each year.
Greg - Do you have a scan device yet? No sense in replacing these parts until a scan reveals the old ones are bad.
With an injected engine you are going to want a scan anytime you have any engine issue. A scan is most always the 1st thing recommended in the diagnostic manuals. Even when a scan does not isolate the culprit it still usually rules out a lot of others that might otherwise get unnecessarily replaced.
With an injected engine you are going to want a scan anytime you have any engine issue. A scan is most always the 1st thing recommended in the diagnostic manuals. Even when a scan does not isolate the culprit it still usually rules out a lot of others that might otherwise get unnecessarily replaced.
Greg, - I have Crusader MPIs and back when I upgrade to the MPOs in 2003 the head Crusader factory tech told me they use only Rinda Technologies Marine Diacon software or Rinda's Techmate (now Techmate pro with better features), so ended up with both those scan devices with the appropriate connector adapter for my engines (plus I purchased a kit to adapt to many other engines.)
The Diacom loaded on my laptop is wonderful as it can display dynamic scan parameter results from 2 engines simultaneously , compare either all or 1 or a few selected parameters from the 2 engines if desired including dynamic graphing and has recording capability so one can record healthy engines as a baseline to compare to if there is a problem later on. It also included the digital extensive MEFI-4 Ignition Diagnostic Manual on the SW CD, so that loaded onto my laptop as well.
The Techmate displays all the same available ECM output parameters , but mine only shows 1 line at a time ( the newer "Pro" version show 3 lines . No graphing or recording ( but the "Pro" may allow notebook connectivity for pass-thru recording, not sure).
I greatly prefer the features of the Diacom for 2-engine use, but readily admit I use the small handheld Techmate way more often (due to its safer portability & stow-ability) to check things like cam retard angle after changing dist cap & rotor & make sure fuel quality remains good so as to not have had the knock sensor cause a timing retard history alert.
There is a cheaper software version , like OBD Mefi-Scan w/o the diagnostic manual and fewer engines it will scan. I haven't tried it.
And others have mentioned a considerably more expensive professional marine scan device CDI's M.E.D.S. which covers a lot of I/B, I/O and O/B's.
I expect there are others ( some just for particular O/B's of course and Volvo Penta's $$$$ VODIA) . But I think the ones above are the most common.
I'm just a boater, but I can't imagine having a computer-controlled marine gas (& maybe diesel) engine without having a compatible diagnostic scan device and adapter . And the appropriate ignition diagnostic manual.
The Diacom loaded on my laptop is wonderful as it can display dynamic scan parameter results from 2 engines simultaneously , compare either all or 1 or a few selected parameters from the 2 engines if desired including dynamic graphing and has recording capability so one can record healthy engines as a baseline to compare to if there is a problem later on. It also included the digital extensive MEFI-4 Ignition Diagnostic Manual on the SW CD, so that loaded onto my laptop as well.
The Techmate displays all the same available ECM output parameters , but mine only shows 1 line at a time ( the newer "Pro" version show 3 lines . No graphing or recording ( but the "Pro" may allow notebook connectivity for pass-thru recording, not sure).
I greatly prefer the features of the Diacom for 2-engine use, but readily admit I use the small handheld Techmate way more often (due to its safer portability & stow-ability) to check things like cam retard angle after changing dist cap & rotor & make sure fuel quality remains good so as to not have had the knock sensor cause a timing retard history alert.
There is a cheaper software version , like OBD Mefi-Scan w/o the diagnostic manual and fewer engines it will scan. I haven't tried it.
And others have mentioned a considerably more expensive professional marine scan device CDI's M.E.D.S. which covers a lot of I/B, I/O and O/B's.
I expect there are others ( some just for particular O/B's of course and Volvo Penta's $$$$ VODIA) . But I think the ones above are the most common.
I'm just a boater, but I can't imagine having a computer-controlled marine gas (& maybe diesel) engine without having a compatible diagnostic scan device and adapter . And the appropriate ignition diagnostic manual.