No Idle 2006 Regal

regal2200blk

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I have a 2006 Regal 2200 with a 5.7 GXi-F. The boat will not idle after warming up. The IAC valve has been replaced and there are no error codes from scan. Any ideas?
 

tpenfield

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Air leak . . . It doesn’t take much. Check for loose hoses leading to/from the intake.
 

QBhoy

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Diz cap and rotor is hands down the most common cause of running related issues on these engines. Well known for it...and on the small chance it isn’t that, you’ve done yourself a favour...because that will fail at some point soon.
All the best.
 

aimlow

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Diz cap and rotor is hands down the most common cause of running related issues on these engines. Well known for it...and on the small chance it isn’t that, you’ve done yourself a favour...because that will fail at some point soon.
All the best.

Is that the GM CSFI system with the flat topped distributor?
 

aimlow

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Those systems are always problems. Timing is not adjustable. Distributor must be set with a scan tool. If the fuel pressure is low, the injectors won't open and work.
 

QBhoy

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How did you get on. Defo change the diz cap and rotor. Should see it right in 10 mins.
 

aimlow

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I've spent a few hours on my distributor machine investigating those crappy distributors. I've cut caps apart. There are sooo many aspects to those dam things which are just plain bad design. In practice, the optimal "cam retard" setting is not 0 degrees, it is retarded a few degrees. If anyone is interested, it's a lengthy explanation.
 

QBhoy

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I am.

a friend is having issues with his 350 mag mpi. I'm not convinced it's the right distributor even. It's blue colour on the cap. It would plane at all until I slightly rotated it anti clockwise by only about 2/3mm. Much better now but still occasional stutters.
 

QBhoy

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I went through two caps this year on mine. One of them failed it out the box. Oem as well.
 

aimlow

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I am.

a friend is having issues with his 350 mag mpi. I'm not convinced it's the right distributor even. It's blue colour on the cap. It would plane at all until I slightly rotated it anti clockwise by only about 2/3mm. Much better now but still occasional stutters.

If it is a flat topped distributor, the distributor cannot be fiddles once it is set with a scan tool, based on "cam retard", or the relationship of the distributor to the crank/cam. The ignition is crank fired and timing is non-adjustable. The cap and rotor must be matched to minimumize the gap between the rotor button and the cap terminals. Plug gap must be set to 0.038", to minimize voltage requirements.

On a v8 engine, a plug fires every 90 degrees, or 45distributor degrees. The software allows 45 degrees advance under certain conditions (on street engines, not sure about marine). In any case, spark scatter and crossfire within the cap is common, especially when the distributor is not properly adjusted.

These things were a plastic POS, specific only to CSFI GM injection, as used on vortec truck engines.

IF you have a cap /rotor set which is working, DO NOT change them. The best caps were the original grey GM caps from the factory.
 

QBhoy

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If it is a flat topped distributor, the distributor cannot be fiddles once it is set with a scan tool, based on "cam retard", or the relationship of the distributor to the crank/cam. The ignition is crank fired and timing is non-adjustable. The cap and rotor must be matched to minimumize the gap between the rotor button and the cap terminals. Plug gap must be set to 0.038", to minimize voltage requirements.

On a v8 engine, a plug fires every 90 degrees, or 45distributor degrees. The software allows 45 degrees advance under certain conditions (on street engines, not sure about marine). In any case, spark scatter and crossfire within the cap is common, especially when the distributor is not properly adjusted.

These things were a plastic POS, specific only to CSFI GM injection, as used on vortec truck engines.

IF you have a cap /rotor set which is working, DO NOT change them. The best caps were the original grey GM caps from the factory.

Totally agree, but this one wasn’t running. Popping and banging. Boat was laid up for a few years. The dealer changed diz cap before it sat for so long and wasn’t ran since. My friend bought it. I took it out and it wouldn’t even go on plane. Merc dealer told me although not the proper procedure and timing on these is set by Ecu as you say, sometimes on older set ups you can fiddle with it. I turned the whole assembly a few mm and it ran 100 times better. Just loosened the holding bolt slightly to do it. I realise that it should be set within the lines as marked and the ecu takes over. Wasn’t the case with this. I’m convinced the dealer put the wrong distributor on it. One off a pcm or something. He is a master craft dealer mainly. The cap is blue in colour. Never seen a blue one for a merc mpi. Oem or otherwise.
 

aimlow

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Totally agree, but this one wasn’t running. Popping and banging. Boat was laid up for a few years. The dealer changed diz cap before it sat for so long and wasn’t ran since. My friend bought it. I took it out and it wouldn’t even go on plane. Merc dealer told me although not the proper procedure and timing on these is set by Ecu as you say, sometimes on older set ups you can fiddle with it. I turned the whole assembly a few mm and it ran 100 times better. Just loosened the holding bolt slightly to do it. I realise that it should be set within the lines as marked and the ecu takes over. Wasn’t the case with this. I’m convinced the dealer put the wrong distributor on it. One off a pcm or something. He is a master craft dealer mainly. The cap is blue in colour. Never seen a blue one for a merc mpi. Oem or otherwise.

Cap color doesn't mean anything. Just an aftermarket cap. ALL those distributors are GM units. No "marine" engine supplier makes the caps, or the motors. They just buy GM made units and paint them their colors. They will use their exhaust manifolds, certain fuel system parts, engine mounts, etc.
 

QBhoy

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Thanks. Aware of that, but I actively searched for one with a blue cap all over the market. None available. After market or not. There were similar caps that were blue for other engines that are found in master craft, Malibu etc etc. With pcm, ford etc
 

aimlow

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Thanks. Aware of that, but I actively searched for one with a blue cap all over the market. None available. After market or not. There were similar caps that were blue for other engines that are found in master craft, Malibu etc etc. With pcm, ford etc

May be out of production. Thankfully, a lot of those CSFI systems are disappearing from use. Been 20 years since they were used on the street. Not as many suppliers making those parts.
 
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