1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

[gsutton]

New Mallory distributor (w/ ignition module) new plugs and wires. Runs rough and will not exceed 3,000 RPM. Also, will not hold prime during starting. Please Help!

 

[b00tstrap]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Could be many things,

Are the plugs gapped correctly?

Are you sure you have the right wires from the distributor to the right cylinders?

What about the timing?

 

[Bondo]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Also, will not hold prime during starting. Please Help!

Please Explain.............

 

[gsutton]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Plugs are gapped properly, wires are correct, adjusted timing yesterday.

 

[gsutton]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

After the boat sits overnight, we have to pump the throttle numerous times to provide enough gas to start.

 

[MelLandry]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Runs rough...

Missfireing on the same cylinder(s) every time? Pull one wire off the distributor at a time and see if something changes. If nothing changes, then that's the cylinder you have a problem with... might be a bad wire/plug out the box. If it changes on every one, you know it's not ignition.

Get really wet first... it'll be an electrifying experience (joking... please don't).

 

[tommays]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

What happened to the orginal distributor and does the new have the same specs for anvance as the orginal


Tommays

 

[gsutton]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Removing 1 and 3 made no difference at idle. All of the other wires affected the idle. This is the Mercruiser replacement distributor with the ignition module.

 

[speedholes]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Not to patronize, but you do have the correct firing oreder, right? 18436572?

It seems strange that two plugs would be not firing correctly, while the others are doing fine.

 

[MelLandry]

Re: 1995 Mercruiser 5.7 Won't Exceed 3,000 RPM

Removing 1 and 3 made no difference at idle. All of the other wires affected the idle. This is the Mercruiser replacement distributor with the ignition module.

Ok... were you getting a spark at the distributor at 1 & 3? You should be able to hear it (clicking) or see it jumping. If the spark is there, check the spark at the plug. If the spark is there, pull the plug and see if the plug is getting a spark.