SC Boost Question....

[Cyrk]

Ok all of sudden my Boost/Vac reads 4 psi when I'm in boost.
I have the 5 psi pulley and it has read 5 until last night?
Where could I be losing boost? or What could be the problem, not sure if I feel a difference or maybe the needle on my gauge got whacked?

Thanks in advance.
-Dave

[Tone]

Slipping belt, vacuum leak, or faulty guage.

[Cyrk]

Thanks Tone will look into it.

[VXtreme]

I also have this same problem with my S/C. I have a 5 PSI pulley on mine also. When the engine is fairly cold, I read 5PSI on the boost guage. When the car is completely warmed up and particulary when it has had the chance to sit and the heat to soak through all the compenents, I read 4 PSI under boost. Does the heat have anything to do with it??

[jayfotos]

This is the same problem I had, I don't have a guage, but when it go dyno'd it read 4psi.

Alpine is sending me a new pulley along with replacement neck. I'm going to measure both pulleys(should be 52mm for 5psi) and see what's up.

As for a vacuum leak, slipping belt how do you correct and spot that?

and would something like that show up on a dyno?

[jayfotos]

This might be the cause, check it out.

Yesturday I got in my truck, started it up and a horrible noise/rattle came from what sounded like from my exsuast(sounded like I had a hole in my muffler). Well, I ran around the corner to were I had my PV put on thinking a weld broke. After inspection the bolt from underneath the ECU valve(I think that's the name of it, #2 on the pic below)

http://www.vehicross.info/gallery/data/500/9011.jpg


holding the exsaust line coming from the what looks like the header came off, dropped down and was rattling like a pissed off diamond back. It was to hot to stick a hand in there to start the tread going to tighten it back up.
This morning I got it on with my hands and brought it over to my shop for them to put it on correctly with a little lock tight so it does'nt vibrate off again(not to much, because it's alumium(sp) and might sease the treads..they told me that).
After they fixed it, I noticed more pep and I bet that might be the problem for your boost loss, leaking exsaust, check it and see if it's loose.

[Dallas4u]

#2 is your EGR valve. The bolt is known to come loose. This has been discussed MANY times in the past. In fact, my dealer even told me they've seen MANY Troopers (maybe even Rodeos) have the bolt come loose.

If that fixes your problem, that's great!

[Cyrk]

I have had the EGR come loose and the VX sounded like a diesel truck, tightened the bolt and sound was gone... Do not think that effected boost at all?

Today I threw 2 codes, P0123 (TP Sensor Circuit Input High) & P1121 (TP Sensor Circuit Intermittent Voltage High)... Truck was shifting REALLY hard and rpms we crawling higher when I was not moving, not fun... going to the dealer when I get back form NY which I leave for tonight. Think, hope that this can be fixed easily and that it might be causing my boost leak.

-Dave

[Green Dragon]

Originally posted by Cyrk
I have had the EGR come loose and the VX sounded like a diesel truck, tightened the bolt and sound was gone... Do not think that effected boost at all?

Today I threw 2 codes, P0123 (TP Sensor Circuit Input High) & P1121 (TP Sensor Circuit Intermittent Voltage High)... Truck was shifting REALLY hard and rpms we crawling higher when I was not moving, not fun... going to the dealer when I get back form NY which I leave for tonight. Think, hope that this can be fixed easily and that it might be causing my boost leak.

-Dave

TP = Throttle Position


Bob F

[VXtreme]

The nut attaching the EGR tube to the valve is tight on mine although it has come lose in the past. I have not thrown any codes but I still seem to lose boost particulary when the engine is completely warmed up and I have driven it while. It seems to occur when it is hot and I let it sit for awhile. That is why I think it has something to do with heat soak throughout the S/C and engine components. I have checked for any vacuum leaks, none found, the belt is not slipping and can find no other cause for the condition. Any advise would help.

[Green Dragon]

Originally posted by VXtreme
It seems to occur when it is hot and I let it sit for awhile. That is why I think it has something to do with heat soak throughout the S/C and engine components. I have checked for any vacuum leaks, none found, the belt is not slipping and can find no other cause for the condition. Any advise would help.

I agree! The SC intake air temp ( Beyond the Air Temp sensor which is just upstream from the MAF sensor) appears to be extremely hot thus affecting compressibility etc.

I have an INJEN Intake attached to my SC which I have wrapped with Plumbers insulating Pipe tape ( Home Depot) to reduce this effect. Just a couple of dollars investment may just prove out for you.

Bob F

[skunkworks]

The intake air sensor should really be as close as possible to the throttle body to give a true reading, also not stuck up and isolated in a long tube like in the Hotshot.

albert
________
Dodge Avenger history (http://www.dodge-wiki.com/wiki/Dodge_Avenger)

[VXtreme]

Check out this link

http://www.truckaddons.com/Catalog/subpages/DEI_heatshields.htm It [COLOR=blue]

They show an air tube cover kit from DEI that goes on and off very easily with hook and loop. I think I will buy one for my cold air intake and see how it works.

[Green Dragon]

Originally posted by VXtreme
Check out this link

http://www.truckaddons.com/Catalog/subpages/DEI_heatshields.htm It [COLOR=blue]

They show an air tube cover kit from DEI that goes on and off very easily with hook and loop. I think I will buy one for my cold air intake and see how it works.

$50 more than plumbers tape just for hook & loop.

Bob

[ScottinMA]

Originally posted by Green Dragon
I agree! The SC intake air temp ( Beyond the Air Temp sensor which is just upstream from the MAF sensor) appears to be extremely hot thus affecting compressibility etc.

I have an INJEN Intake attached to my SC which I have wrapped with Plumbers insulating Pipe tape ( Home Depot) to reduce this effect. Just a couple of dollars investment may just prove out for you.

Bob F

Bob, do you have a pic of your intake? I've been trying to find an intake solution since I got the SC.

[jayfotos]

I think I'm going with this intake(with sight moding), I like the idea it's insolated to keep it cool running along side the engine. I'm still on the search for a air box to go long with it, should'nt be to hard..there's a billion to choose from and with some slight moding should work fine.

http://images.channeladvisor.com/Sell/SSProfiles/30057151/Images/H-002BGC-D.jpg

[jayfotos]

If the heat soak is what the problem is would'nt your 4psi pully be running at 3psi same as your 5psi running at 4psi?

[Cyrk]

Picking up the VX from the dealer tonight, they replaced my MAP senor and my TP sensor, wonder if this will fix the loss in boost?