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dave123

230 ssi knock and running rich

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I have a 2004 230ssi with a vp 5.7 gi-e. It fires right away on a cold start but runs rich all the time. It will not start when its warm unless throttle is applied or I unplug the pcv hose from the manifold behind the throttle body. In fact it only runs good at idle with the pvc hose unplugged. The smoke also clears when the hose is unplugged. the iac valve does function and was replaced last year with one from orielliys. Also changed mass air sensor, crank position sensor, knock sensors, temp sensor, manifolds and risers, tps sensor, ac delco plugs, marine cap and rotor. I checked the timing chain and it was like new. a timing light shows that it is advancing the timing as the rpms go up. it will run under 3500 rpm all day but if i push it harder it will knock and backfire. Any suggestions on where to go from here? I think it is starving for air but that doesn't explain the high rpm knock.

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1 hour ago, dave123 said:

I have a 2004 230ssi with a vp 5.7 gi-e. It fires right away on a cold start but runs rich all the time. It will not start when its warm unless throttle is applied or I unplug the pcv hose from the manifold behind the throttle body. In fact it only runs good at idle with the pvc hose unplugged. The smoke also clears when the hose is unplugged. the iac valve does function and was replaced last year with one from orielliys. Also changed mass air sensor, crank position sensor, knock sensors, temp sensor, manifolds and risers, tps sensor, ac delco plugs, marine cap and rotor. I checked the timing chain and it was like new. a timing light shows that it is advancing the timing as the rpms go up. it will run under 3500 rpm all day but if i push it harder it will knock and backfire. Any suggestions on where to go from here? I think it is starving for air but that doesn't explain the high rpm knock.

+1 to fuel pressure check. 

The symptoms and corrective action suggest a failed pressure regulator. 

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I was just watching a video on YouTube and they said there is a needle valve in the fuel pump and if it doesn't seat well it will make the engine run rich. I'll have to test my pump tomorrow and see what I can find.

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I think you may be stuck in a cold engine condition. That rich condition will ruin oil & soot up sparkplugs & all the valves. 

I think your engine is running in a full choke condition.  THe starting of a warmed up engine with a faster throttle position is the right way to start very rich / flooded engines.

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You have a multi-port fuel injected engine. Suggest checking fuel pressure. Understanding this before additional remove and replace is important. You’ve replaced almost everything that can have an effect, and you seem to have confirmed timing. If you need the pressure spec., I’ll post it later this morning. It’s in your manual as well. On a GX-I, it’s 50 to 60. Your fuel system is the same, but sometimes Volvo Penta throws a curve so I need to confirm when I fire up the laptop later. The most important part of your original post is the comment on the “pvc hose”.

P.S. Is it safe to assume you checked the flame arrestor, it’s clean, and no flow obstruction?

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I removed the flame arrestor long time ago and put a high flow filter instead. I think an engine should have clean air and a flame arrestor doesn't filter at all. I'm going to check fuel pressure today if I can get a gauge from my parts store. I also want to remove the regulator and make sure its clean.

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Suggest leaving the regulator alone until after the pressure check. Debris might be an issue, but there are other modes of failure.

As to air filter, suggest pulling it and testing without.

 

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Curt is right about removing the air filter. 

Boats & that filter live in 100% humidity CONSTANLY.  The paper based filter can soak up moisture causing super high restrictiongs at idle and low speeds. 

EDIT

Whatis

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2 hours ago, dave123 said:

I removed the flame arrestor long time ago and put a high flow filter instead. I think an engine should have clean air and a flame arrestor doesn't filter at all. I'm going to check fuel pressure today if I can get a gauge from my parts store. I also want to remove the regulator and make sure its clean.

Careful, also.  If I'm not mistaken, a flame arrestor is required by USCG/USA boating regulations. 

When we got boarded a few years ago, that was one of the first things the officer checked as soon as I opened the engine hatch.  Pretty sure it's the same requirement for fresh water/lakes etc..

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What is the knocking about ? What speeds & conditions ?

The very rich running could have built up glowing carbon spots causing … pre firing of the cylinders.

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Under a load over 3500 rpm for around 5 minutes or more. I just picked up fuel pressure test kit. Should know more n about a hour.

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18 minutes ago, dave123 said:

How do I test the temp sensors in the exhaust? 

You need a scan tool for that.  Or if you have Vessel View hooked up, that can tell you if you have a sensor problem or a mechanical one.  Not sure there's any other way to test a sensor.

At least your feul pressure looks good.

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1 hour ago, dave123 said:

How do I test the temp sensors in the exhaust? 

Fuel pressure is fine at idle. What is it under load at the rail?

You don’t need a scan tool. Do you have a multimeter? If you do, I’d be happy to post voltage so you can confirm correct operation.

Any change with the filter off?

Finally, have you “spayed” carb. cleaner into the throttle body?

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The boat is on a trailer so I cant test under a load. Maybe tomorrow the weather will clear for a test under a load. I have a few multimeters but never have luck testing sensors with them. I haven't sprayed carb cleaner in it. I dipped the throttle body for about 36 hours the other day. And there is no change when I remove the filter. I know it's not legal to run w/o spark arrestor but I'll take my chances to have clean air. 

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Yeah I'd like to learn how to test a sensor with just a multimeter.  That would be a cool new thing to add to the list of little tricks

This is just my opinion, but I would think you'd get more air through a flame arrestor than your standard, felt air filter or even one like a K&N filter, no?  The arrestors are just a bunch of wire mesh layers put together.  Seems like it would be less restrictive.   

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I downloaded a repair manual and it doesn't mention the temp sensors on the exhaust having an effect on the ecm. It shows the one on the thermostat housing communicates with the ecm. I've already replaced it. I might have to throw in the towel and find a dealer with a scanner. I've talked with 2 marine mechanics and they didnt get me any further than I already was. Neither has a scanner. They said stick to the basics to fix it.

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Now im going to check if the temp sensor in the thermostat housing is getting 5 volts. Then im going to let the motor warm up and run jumper wires to ground the exhaust temp sensors. something is making it run rich and i hope its not a bad ecm. Ill have to find a dealer w a scan tool to determine that.

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39 minutes ago, dave123 said:

Now im going to check if the temp sensor in the thermostat housing is getting 5 volts. Then im going to let the motor warm up and run jumper wires to ground the exhaust temp sensors. something is making it run rich and i hope its not a bad ecm. Ill have to find a dealer w a scan tool to determine that.

Agree, logical next step. The ECT interfaces with the ECM and adjusts timing. This is either a fuel system or electrical issue (affecting timing) based on described symptoms. Suggest pulling the fuel pressure regulator since you’re working on it, and seeing if there’s evidence of clogging. Pressure readings don’t indicate a problem, but the description of symptoms points in this direction. Failed spring/diagram. 

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2 hours ago, Hatem said:

Yeah I'd like to learn how to test a sensor with just a multimeter.  That would be a cool new thing to add to the list of little tricks

This is just my opinion, but I would think you'd get more air through a flame arrestor than your standard, felt air filter or even one like a K&N filter, no?  The arrestors are just a bunch of wire mesh layers put together.  Seems like it would be less restrictive.   

Each sensor has voltage parameters. If you know the values, specific to the sensor of interest, they're easy to troubleshoot. Being able to do this comes in handy when a code is not being set for whatever reason.

Personally, I get rid of the filter. No need unless boating where the air is dusty and dirty. Can’t recall every seeing conditions that warrant a filter. Been around this for more decades than I care to admit.

Finally, this situation is perfect for Diacom and Vodia. Being able to see the pulse, graph everything, etc. highlights what’s normal and abnormal.  

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The temp sensor is getting 4.8 volts which is n spec. And 550 ohms at 150 degrees which is n spec. The exhaust temp sensors are getting 11.3 volts but I cant find any info on them. Guess it's time to scan it.

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