Can you guys give me a list of everywhere possible one could have a vaccum leak on the 2.8 that would mess the idle up big time.

 

How bad? when mine was doing it really bad, it was at where the upper plenum met the lower plenum, the intakes have never been pulled off before i got it and the old GM gaskets disinegrated, the only thing that was letting the car idle was dirt and crap that built up!!!

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1989 Firebird. Modded.
700r4-->t5 w/ram clutch
Cold air, 1.6 rockers, 21lb injectors, 3" y-pipe, random tech cat, 3" ipipe, flowmaster 80 series 3" in 3" out hand made stainless tips, Lakewood LCA's, Msd 6a, Msd coil, Wonder Bar, 180* stat,
Coming Soon: T/a hood, Painted,Spohn Panhard Bar, 4thgen Front Seats, Cam!, Msd 8.5 wires, Posi (ACCEL IS CRAP)
"I'd rather run last in a full out race, than to NOT have run at all"
See my car Here!
In Memory of #3 Dale Earnhardt

 

Is there supposed to be a gasket between the upper most intake piece(the one with badge on it) and the next lower piece? Mine never had one. It is just metal to metal. Could that be why my idle is a little rough?

Dale

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1986 FireBird
2.8L MPFI
1/2 CAI
Gutted Cat, No muffler
Was 700-R4 --> Now T5

Great cars aren't bought, they are built

 

All new upper and lower intake gaskets.... So that is out..

 

86 chicken..YES! Dude..how is your car even idling?? Isnt your MAF sending codes and your idle up and down and ****ty gas mileage? Mine was still somewhat there and it happened to mine... and when i fixed it my power went up from when the gaskets were messed up.

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1989 Firebird. Modded.
700r4-->t5 w/ram clutch
Cold air, 1.6 rockers, 21lb injectors, 3" y-pipe, random tech cat, 3" ipipe, flowmaster 80 series 3" in 3" out hand made stainless tips, Lakewood LCA's, Msd 6a, Msd coil, Wonder Bar, 180* stat,
Coming Soon: T/a hood, Painted,Spohn Panhard Bar, 4thgen Front Seats, Cam!, Msd 8.5 wires, Posi (ACCEL IS CRAP)
"I'd rather run last in a full out race, than to NOT have run at all"
See my car Here!
In Memory of #3 Dale Earnhardt

[This message has been edited by Graeme'sFirebird (edited September 05, 2001).]

 

Actually, I get 30mpg regularly (combo town/hwy), have not too bad power (can chirp in second gear w/o dumping the clutch) and no codes. Kinda strange with no gasket, if it is that important. I made sure the bolts were nice and tight last time I put it together to be safe.

The only thing is the rough idle. It is rough but it stays at a steady RPM(650-800 is a guess, I haven't driven the car lately).

I actually kinda like the idle, it makes the car sound like a V8 (almost) until I step on the gas. I will be putting on gaskets when I do my ported head/cam swap but I was just curious.

Dale

[This message has been edited by 86Chicken (edited September 05, 2001).]

 

It is throwing NO CODES and that is confusing...

 

Brian I hear ya.
Check ALL PLASTIC LINES
They may be damaged.
ALSO at the EGR valve by the original factory coil set up, check those hoses.
BRIAN, follow every plasic hose you find 90% of it is fixed by 5/16" windshield wiper hose
I also got some 1/4" for good thoughts!!
By distb base is the 1/2" one.
keep checking & following evry olast one. Pull out connections carefully. Many times ya toucch it it cracks. I know!!
BUT, I just fixed my problems (codes 32 & 34) but two 1 inch sections of hose!!!
You can to!
I still have to do my one at base of the distb, again, it got messed up when the guy did the tranny! It's "ok" but, i know it's not perfect.
I am missing about an inch of vacuum pressure.
(15.5-16-17, instead of 17-18)

Use a vacuum gauge every day or your driving to check results.
I do!

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

hey maybe you guys can help me out with my car
if you car has a vac leak it should run lean right? also can a vac leak cause the car to almost act as though it has spark cut. I know when I had a bad intake leak the car just sputtered thats all. but now it runs and idles really rough. but I have no power and sometimes it will just cut out almost like I turned the motor off

 

It certainly can make your ride act like that.
FI vehicles need a constant STEADY VACUUM SOURCE, NO LEAKS OF ANY TYPE (fuel or vacuum).

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

Anyone in Central Flordia area want to take a look, I can't find a thing...