Vacuum hose routing

vocaldog

VocalDog
Joined
Jan 11, 2008
Messages
153
Location
Southampton, NY
Ride
2005 Rocket Standard
Does anyone know where I can get a schematic of the vacuum hose routing on an '05 standard? I couldn't find it in the service manual. Using tune ECU I'm getting 960 on two cylinders and 970 on the third while cranking, which is evidently barely above normal atmospheric pressure. I've checked the obvious hoses- the 3-way connector and MAP sensor hoses and such that I can see under the tank, but I'd like to investigate a little deeper. DECosse, I understand if our want to si this one out! LOL
 
Your vacuum lines are under the air cleaner piping. Remove the piping and it will be right in front of you. Easy peisy to replace the vacuum lines. The hard part will be putting the air cleaner piping back in. :eek:
 
I think I pointed you that way regarding the pressure - but this time, I'm not 100% sure about that 'advice' - whether the software actually reports the gauge reading while it's cranking, vocaldog or only after it starts
Maybe someone could check/validate one way or other on that?

I don't think there is a diagram that exists for the pressure monitor hoses, but it's simple enough - there are 3 hoses, one from each throttle body, that connect into a 4-way splitter, with the 4th one going via a hose to the air pressure sensor.
Just make sure that all the hoses are secure and there are no open ports that can suck air.

On a different tack:
Can you hear the Fuel Pump run when you first turn on the key-switch?
 
I think I pointed you that way regarding the pressure - but this time, I'm not 100% sure about that 'advice' - whether the software actually reports the gauge reading while it's cranking, vocaldog or only after it starts
Maybe someone could check/validate one way or other on that?

I don't think there is a diagram that exists for the pressure monitor hoses, but it's simple enough - there are 3 hoses, one from each throttle body, that connect into a 4-way splitter, with the 4th one going via a hose to the air pressure sensor.
Just make sure that all the hoses are secure and there are no open ports that can suck air.

On a different tack:
Can you hear the Fuel Pump run when you first turn on the key-switch?
Yes, you were the one that tipped me off to the low pressure. I'm about to check all the hoses now. And yes, the fuel pump runs for a few seconds when ignition is turned on. Someone suggested spraying starter fluid into the air filter to see if it fires. Good idea?
 
Tighten your coil lead wires first. You have 3 coils the one in the front by the head stock is a pain to get to. The reason I am saying to do this first is that it will start but run rough sounds more like the coil wires are loose. On a 2005 the vacuum lines need to be replaced to but Tighten the coil wires first
 
It may also be worth while checking a spark plug or two if the above doesn't work.

Those vacuum readings don't sound too bad to me for cranking - without the engine running. I wouldn't expect much of a vacuum build up as there is plenty of time for air to rush back in. Have you tried starting it with jumper leads from a car or truck with a good strong battery? If it works that way, then you have a voltage drop because of a bad connection at some point.

btw, if you have the original air plumbing then this may be a good time to consider triple fliters or RamAir options. They make life a LOT easier.

Another thing to try - although you should NOT do this normally - is to crank the throttle open as you are cranking the engine. (The reason that you should not do this normally is that it will affect where the ECU sees the 0% throttle position - causing rough idling (or engine cutting out) and poor response. The easy way to correct it is to make sure that the throttle is all the way off when starting the next time.) Spraying starter fluid into the air filters probably has a similar effect, but also has potential for other, shall we say more interesting, effects.
 
Tighten your coil lead wires first. You have 3 coils the one in the front by the head stock is a pain to get to. The reason I am saying to do this first is that it will start but run rough sounds more like the coil wires are loose. On a 2005 the vacuum lines need to be replaced to but Tighten the coil wires first
Yup. I've tightened the leads to two of the coils so far. I'm about to scrape my knuckles bare in an attempt to get to that third one.
 
It may also be worth while checking a spark plug or two if the above doesn't work.

Those vacuum readings don't sound too bad to me for cranking - without the engine running. I wouldn't expect much of a vacuum build up as there is plenty of time for air to rush back in. Have you tried starting it with jumper leads from a car or truck with a good strong battery? If it works that way, then you have a voltage drop because of a bad connection at some point.

btw, if you have the original air plumbing then this may be a good time to consider triple fliters or RamAir options. They make life a LOT easier.

Another thing to try - although you should NOT do this normally - is to crank the throttle open as you are cranking the engine. (The reason that you should not do this normally is that it will affect where the ECU sees the 0% throttle position - causing rough idling (or engine cutting out) and poor response. The easy way to correct it is to make sure that the throttle is all the way off when starting the next time.) Spraying starter fluid into the air filters probably has a similar effect, but also has potential for other, shall we say more interesting, effects.
Yeah....I am strongly considering the ram air setup. Did I hear that there is a 2nd generation ramair that has a better fit? Or is there only on ramair option? Are you suggesting that I replace all the vacuum lines regardless of my current problem?
 
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