rpm dips and voltage drops

[LETZRIDE]

Ive been researching this for awhile now, and trying to figure it out myself with no luck. My car everytime I go to slow down drops to the top red line on the voltage gauge and my lights dim. From what I have gathered from live data scans, when this happens my rpms drop to about 600-700rpm (i have my idle set to 960rpm) and you can feel the car shudder

If I blip the throttle any my gauge shoots right back up and my lights are all bright again as if everythings normal.

Seems to me like the issue is being caused by my rpms dipping, so what can cause this/how can i fix it?

I dont have a sound system, but I do have a racetronix fuel pump, electric water pump and 2 gauges...

[FirebirdGT]

Re: rpm dips and voltage drops

Take the IAC out and clean it with TB cleaner. They stick.
.

[LETZRIDE]

Re: rpm dips and voltage drops

Take the IAC out and clean it with TB cleaner. They stick.
.

I put a brand new one in maybe a month-1.5 months ago...had the problem prior to that as well though, and it never fixed the issue with the new one.

[Pewter02Camaro]

Re: rpm dips and voltage drops

Ive been researching this for awhile now, and trying to figure it out myself with no luck. My car everytime I go to slow down drops to the top red line on the voltage gauge and my lights dim. From what I have gathered from live data scans, when this happens my rpms drop to about 600-700rpm (i have my idle set to 960rpm) and you can feel the car shudder

If I blip the throttle any my gauge shoots right back up and my lights are all bright again as if everythings normal.

Seems to me like the issue is being caused by my rpms dipping, so what can cause this/how can i fix it?

I dont have a sound system, but I do have a racetronix fuel pump, electric water pump and 2 gauges...

Welcome to my world. lol. I've been dealing with this for a while now, unfortunetly I can't help you out a whole lot with this one. I have talked with the guy that tunes for me quite a few times about this. He tells me that he simply does not have acess to the proper tables to trim this out, thoug my cars an '02. When i stepped up to the GT2 from the GT1 it became very apparent. I do have a couple questions for you though, does it clear up the instant you come to a stop? have you ever had it die on you in the process?

[pbryant_knight]

Re: rpm dips and voltage drops

I had this on my Nissan 300zx. It was really stupid. I was using regular unleaded and when I slow down or stop the revs dipped and eventually cut out. started using super unleaded and it never done it once. Probably not the same problem but might be worth a bash.

[97rs4life]

Re: rpm dips and voltage drops

switch back to your factory cam to fix it ;) Anyone with a larger cam deals with it

[Blizzard242]

Re: rpm dips and voltage drops

I had the same problem when I was tuning my car. Bad enough as to when I was coming to a stop it actually died on me. I leaned my tables up a little and that cleared it up. It's still not 100% since I'm still dealing with faulty headers but it's much better.

[LETZRIDE]

Re: rpm dips and voltage drops

Welcome to my world. lol. I've been dealing with this for a while now, unfortunetly I can't help you out a whole lot with this one. I have talked with the guy that tunes for me quite a few times about this. He tells me that he simply does not have acess to the proper tables to trim this out, thoug my cars an '02. When i stepped up to the GT2 from the GT1 it became very apparent. I do have a couple questions for you though, does it clear up the instant you come to a stop? have you ever had it die on you in the process?

not always, it does and it doesnt...sometimes right when I come to a stop she'll rev right back up, sometimes its a few seconds and she comes back. She's never died on me yet because of it.

Car has to use premium fuel lol, so it's not a fueling issue.

damn it Travis...this is your fault for selling me this go fast cam

I feel like this is putting sooo much strain on my alt. What is it about the cam(s) that is causing this? lack of vacuum? would maybe adding an addition vacuum canister help this? They're only like 35$...

I know this is happening because my rpms are dipping though, anytime my rpms arent down at 600-700rpm she's fine, only when the rpms fall it has issues.

[97rs4life]

Re: rpm dips and voltage drops

yea vacuum issue with a larger cam is usually the culprit. yea yea, going fast has drawbacks. lol

[enzia35]

Re: rpm dips and voltage drops

But what would the fix be?

[transamtom1]

Re: rpm dips and voltage drops

But what would the fix be?

You pull vacuum into the brake booster when you stop and thats what causes the problem.

You could eliminate the brake booster and have manual brakes or you could retrofit the Hydraboost sytem that the Buick GN's used.

[Blizzard242]

Re: rpm dips and voltage drops

http://www.jegs.com/p/JEGS-Performan...63083/10002/-1

"The JEGS vacuum canister gives you an extra shot of vacuum that the new cam won't allow you to have in order to feed your power brakes."

[LETZRIDE]

Re: rpm dips and voltage drops

well I guess I know whats next on the list then...

[WarShrike]

Re: rpm dips and voltage drops

Not sure also whether it is the alternator as well. I added a voltage booster and then the alternator rewire just to try and get around some of that issue along with the pulsing lights I'd get sometimes. Things seem a bit better.

A vac canister is a great Idea with a larger cam.

[Pewter02Camaro]

Re: rpm dips and voltage drops

switch back to your factory cam to fix it ;) Anyone with a larger cam deals with it

At idle my car pulls 14-16 in/hg. Where does that put me in comparison to stock?