RPMS drop low after i rev the engine

[boosted954g63]

Every time i rev my engine my RPMs drop down to around 0 then my dash lights come on and then it bounces back up to normal idle at 900. I checked the battery and alternator to see if that works and it did not. I also unpluged the ISC to see if i changed the idle and it did not change any thing. I am going to do a boost leak test after i get done with posting this. I am totally lost on what could be causeing this. Any help would be great.
Thanks Nick

 

[Dream On]

You could try taking off the ISC and cleaning it and the throttle body. Just a thought.

 

[boosted954g63]

I am still waiting to find a used ISC in KS. Going to clean mine this sunday to see if that solves anything.
Thanks Nick

 

[boosted954g63]

A little update in whats going on. I cleaned out my isc and my throttle body and it still does the same thing. I noticed in the intake manifold that it covered in carbon build up really bad. Would that mean that i have a leak in my intake manifold cause there is so much carbon? I am not sure if that is correct but thats what i was thinking. Anything else that i can do before i have toi go buy a Isc?
Thanks Nick

 

[boosted954g63]

Does any one have any clue why it is doing this? I am still really lost on what to approch next.

 

[SRTthis]

Does any one have any clue why it is doing this? I am still really lost on what to approch next.

if you do a WOT run and just push the clutch in does it do the same thing?

 

[EclipseTrbo420A]

This really sounds like a BOV problem. What does your car sound like when you blow off? Is it a nice Type-S highpitched whistel ? or is it choppy? Like Cha cha cha cha cha. What will happen is, instead of the BOV blowing the excess pressure off it will makes it way back to the compressor wheel and stop it from spinning ( to an extent ) and that intern slows the turbo wheel and makes it harder for the motor to flow out the exhaust causing it to amost die and RPM's to fall. Throw your stock BOV back on for a run and see what happens.

A good way to check the ISC is to sit at ilde and turn the air on full blast...if the RPM's drop and stay low your ISC isnt compensating if they drop and come back to normal then its OK.

 

[boosted954g63]

SRTthis-----
if you do a WOT run and just push the clutch in does it do the same thing?//

It does it worse that just sitting and reving it up.

EclipseTrbo420A-----

Thae BOV sounds normal like it did when i baught it. I will check both of those ideas when i get home.

Thanks For the fast help!!
Thanks Nick

 

[EclipseTrbo420A]

SRTthis-----
if you do a WOT run and just push the clutch in does it do the same thing?//

It does it worse that just sitting and reving it up.

EclipseTrbo420A-----

Thae BOV sounds normal like it did when i baught it. I will check both of those ideas when i get home.

Thanks For the fast help!!
Thanks Nick

See, I think SRT4this and I are thinking the same thing. Whats normal sounding? Honisty I would put the stock bov back in just for one run and see it the RPM's still drop.

 

[SRTthis]

it sounds like the stall issue with the 03/04 cobra's which is a problem with the IAC not respoding fast enough i believe. but id do a search on modfords.com or svtperformance for "stall" in the 03/04 cobra section.

as for the name if ANYthing it srt10this since im a lightning owner and really hate srt10's

500hp and cant run 12's thats sad if you ask me...

 

[boosted954g63]

Ok i put the stock BOV on it and it still does the same thing. I let my car idle at 1k rpm and turned on the the air full blast and it went down to like 750 rpms and then back up to like 900 rpms. I will check on modfords.com tonight if i have time. O ya my type -s sounds like a highpitched whistel.
Thanks every one for the great help.
Nick

 

[this_tsi_8urV8]

OK, for the life of me I cant think what BISS stands for. Aaaargh!!! WTF....and where is it at?

 

[pnishr]

BASE IDLE SET SCREW. There's a rubber plug (or should be) on the front/top of your throttle body. It's under there. It is a screw that allows air to bypass the throttle plate to adjust the idle speed.

 

[boosted954g63]

I already checked the BISS screw, it was fine.
Thanks Nick

 

[injection]

hey i've read through this whole post and i just wanted to throw in my 2 cents. i noticed you said your cel had a map sensor code. a map sensor will make a vehicle idle weird. i had a trans am that had a rough idle (it would idle up and down until it warmed up) and found it was a map sensor. have you changed that?

 

[boosted954g63]

I have not changed the map sensor yet. I took it out and cleaned it and it did not work. I am going to try to get another OBD-II reading in the next couple of days to see which ones are still there.
Thanks Nick

 

[TheRealist]

How would you check the Biss O RING? Keep turning biss screw clockwise till it comes off??

 

[boosted954g63]

Ya thats what i did and it was good and also i put some sealent on it too just to make sure it was not leaking and it did not work.

 

[boosted954g63]

Does any one else have any more ideas? I am totaly lost on what to do and i really dont want to take it some where to get fixed.

 

[dieseltech]

I had a 1g that did this similar thing. I changed the fuel filter even though it was good. It had new plugs and wires in it. One day it wouldn't hardly run. It was cutting out and missing like crazy. I thought about it for a bit and came to the conclusion it had to be fuel related. I decided to take an ohm reading of the injectors. Once the connector was removed, much to my suprise, there was corrosion in the connections. I took a small file and cleaned the injector connections. I used a small pick to scrape away at the terminals inside the connectors (i felt like a dentist ). Something quick and easy to check. And as stated before if you have a MAP code i would also investigate that thorughly.

 

[boosted954g63]

Alright i will do that tomarrow! Thanks for the idea! Keep them coming.
Thanks Nick

 

[boosted954g63]

Ok i cleaned my injector terminals and it did nothing. I put my type -s BOV back on and it ran alot better than the stock one. Any more segestions??
Thanks Nick

 

[brute]

Do you still have the misfiring/studdering problem? Or are we just worried about the rev, rpm dip down thing?

 

[boosted954g63]

It still has both, but i am just trying to get the idle situation taken care of. Even though i have had the misfire problem for like a year i just want to be able to drive it again with no idle dip.

 

[Gs Dewd]

HAve you tried resetting the ecu from where you unplugged the isc? Try that run it then recheck the codes and let us know whats going on. Seems like a awful lot of codes being throw and the car is still running ok.

 

[boosted954g63]

By reseting do you mean just unhooking the battery? I unhook my battery every timei get done working on it.
Thanks Nick