Misfire under load 07 vlx

[Flex400]

2 hours ago, Sixball said:

So without going back through all the posts did you look at the screen at the fuel inlet on the fuel pump? I thinking I saw you did but not sure. Might be worth pulling the fuel line off at the pump and tank and blowing it out with compressed air.

As far as I'm aware the 07 doesn't have a screen unless your talking about the socks or screens right under the fuel pump if u are talking about them yes I did blow them out. @Sixball

[Flex400]

Also if your talking that there should be a screen right where the fuel line goes onto the fuel pump I am pretty sure that there isn't one on the 07 just the little filter on top of the pump.

[Trucker]

I had a simular problem last year and the Forum mentioned the filter screen inside the fuel intake line. Pulled the line, shot some carb cleaner up in it and put the line back on. Changel the in line fuel filter and she ran like new. 

[Flex400]

3 hours ago, Trucker said:

I had a simular problem last year and the Forum mentioned the filter screen inside the fuel intake line. Pulled the line, shot some carb cleaner up in it and put the line back on. Changel the in line fuel filter and she ran like new. 

Hi @Trucker is your got the fuel pump inside the tank or outside if it is inside can u show me picture of where the screen is as I don't see it on mine being an 07mdl I thought the only filters are in top of the pump in the tank and at the bottom of the pump it has the screens correct me if I'm wrong.

[Flex400]

Update I've had it down at my mates work shop and we put a fuel pressure gauge on it and it is having a fuel pressure drop so it's looking like the pumps stuffed but can anyone confirm if there is anymore fuel filters on a 07with the pump in the tank I have changed the one on that goes in the top of the pump and also pulled the pump out and cleaned the screens at the bottom is that it I know the earlier models that have the external pump have the screen in the fuel line but I didn't think the 07 does!

[Trucker]

Sorry. Mine is an '06 and it's on the side of the motor, not in the tank. 

[Flex400]

Ok so my mate had the scan tool on it today and he said that the throttle intake sensor is reading -48 so he is saying that because of that it is telling it run with the choke on all the time basically so where is the throttle intake sensor? Is it in the throttle position switch? Need some advice from all u mechanical guys 

Cheers Al

[jbower]

I believe it doesn't have one and that's why it's reading -48. Gm engines of that era took intake temp from the mass air flow sensor and your boat doesn't have one of those. 

The map sensor may read intake temp which could cause your symptoms. Maybe look at what your map is doing in the data stream

Edited April 6, 2017 by jbower
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[Flex400]

I'm sure my mate will know where the map sensor is but can someone tell me where it is?

[Flex400]

Ok so I have an update the mechanic has found that it is dropping spark now we have changed plugs, wires, rotor button, distributor cap he has tried a different coil and so far nothing has worked has anyone got any ideas?

[minnmarker]

2 hours ago, Flex400 said:

Ok so I have an update the mechanic has found that it is dropping spark now we have changed plugs, wires, rotor button, distributor cap he has tried a different coil and so far nothing has worked has anyone got any ideas?

Have you tested the resistance of the wires?  They can come bad from the factory.

Timing?  Distributor position?  If the distributor cap is not just right the spark from the rotor to the cap can miss when the timing advances.  Cool video of a clear rotor

 

[Flex400]

4 hours ago, minnmarker said:

Have you tested the resistance of the wires?  They can come bad from the factory.

Timing?  Distributor position?  If the distributor cap is not just right the spark from the rotor to the cap can miss when the timing advances.  Cool video of a clear rotor

 

I'm not sure if they have tested the leads I will ask them today and see what they say and thanks for that video 

[tvano]

any chance the timing is not being set in diagnostic mode?

base timing must be set with a jumper in place on my '04 to force diagnostic mode.

i suspect that is the case in your rig, too.  

[Sixball]

I will give you an easy try and is not extremely likely but I know from experience.  Try another battery.  If you have more then one, start with A single battery that you know is good. When we ran our drag car I spent two weeks chasing a miss. Every part of the ignition and fuel system was changed and days at a track testing and still a miss. This was only on a run! I could get a clean 9,000 RPM in the pits or at the starting line. As soon as we left the line I was shooting ducks. With still a miss in the car we set of for a division points meet as we needed to have them to qualify for entry in to national races. So the morning of qualifying I run the car down to the scales as we had rain the day before. As I thought we were showing sixty pounds heavy. So back to the trailer remove one of two battery's and some lead both new so they were not looked at other then checking volts and amps. Up to the line for a run and DAMMER it flew down the track clean as a Wiesel and a good number also!  Back to the pits, after a moment of thought we pulled the battery put the other new on in and make a run. Shooting ducks as soon as the car left the line!  In the end the battery had a lose plat in it and would only show up under load ( movement ) as it grounded agency the plat next to it. I can't even tell you all the crap we went through looking for the problem.    

[Flex400]

Ok so I just got back from the mechanics and he tells me that the spark is completely cutting out and tells me that it can't be timing or a bad lead as it's not to any one cylinder he said that they are going to replace a modual in the distributor next.

[minnmarker]

3 minutes ago, Flex400 said:

Ok so I just got back from the mechanics and he tells me that the spark is completely cutting out and tells me that it can't be timing or a bad lead as it's not to any one cylinder he said that they are going to replace a modual in the distributor next.

I'm not positive but it could be the distributor position - which would affect all cylinders.  Worth a try before replacing expensive parts.

[Flex400]

6 minutes ago, minnmarker said:

I'm not positive but it could be the distributor position - which would affect all cylinders.  Worth a try before replacing expensive parts.

He said that when it's on the scan tool with the timing light it is doing everything that it should be except that it is cutting out no spark at all so he said not a timing issue and has to be a fault modual or something that's why he said process of elimination and to start of with things that are cheap first so I guess I will see how we go.

[minnmarker]

Just now, Flex400 said:

He said that when it's on the scan tool with the timing light it is doing everything that it should be except that it is cutting out no spark at all so he said not a timing issue and has to be a fault modual or something that's why he said process of elimination and to start of with things that are cheap first so I guess I will see how we go.

That sounds fine as long as he's seeing normal operation at idle and when blipping the throttle to advance the timing.  I think you said your misfires occurred under load?

[Flex400]

19 minutes ago, minnmarker said:

That sounds fine as long as he's seeing normal operation at idle and when blipping the throttle to advance the timing.  I think you said your misfires occurred under load?

Yes that is right he is seeing normal advance when he is raising the revs from idle.

[Flex400]

Hi guys still not fixed yet! One thing I want to ask if anyone knows if a ecu from a 07 vlx 383 hammer head motor will work in my boat as we want to try     a different  ecu which can get my hands on one to test and if it fixes it well then I will buy a new one but if not then I'm not out of pocket.

thanks in advance ?

[Flex400]

Ok so I have an update I have taken my boat from the work shop that was working on it as he has ended up saying that it needs the computer replaced but I was not happy with that as he has replaced all moduals and what ever else but he kept saying that it would not be anything with the distributor as it was advancing how it should be! Well since I got it back my father in law who is a retired auto electrician came around and started going over everything and straight away found that the timing was all erratic so straight away we pulled the distributor out and found that the gear is badly worn so know I'm having a problem finding a new gear over here in Australia can anyone point me in the right direction to find a new one for a 07 lcr 320 has his hvs  distributor I'm happy to ship it from the USA.

 

Cheers

Alastair

Edited May 15, 2017 by Flex400

[boardjnky4]

Bakesonline.com should have it

[skurfer]

I would get an entire new distributor!

[Flex400]

Just now, skurfer said:

I would get an entire new distributor!

The distributor has had new rotor button, cap and the modual replaced so it's practically new and if I can get a gear for reasonable price that will be the go but if a gear is to much I will just replace the whole distributor.

[skurfer]

I hear you, they are spend but I would get an Indmar distributor