i need a speed density upper plenum, i have the wrong year and a serious vacuum leak, i will pay for shipping. thanks in advance.

 

You could always just drill and tap another vac port on the back of the passenger side and connect the map sensor there....

 

thats not my problem, what happened is i have a SD (speed density) throttle body, SLP SD runners, 86 manifold and MAF plenum, there is a vacuum leak on the drivers side. i have the MAP hooked up. thanks for the reply

 

Sorry, I guess I'm just slow/dumb, but I don't see how changing the plenum will solve the vacuum leak.... why do you need a new plenum to do that?

 

Unless the plenum is physically damaged or warped, replacing that component of your setup shouldn't fix anything, I'm with vernw... The only differences would be an extra vacuum port for the MAP sensor, and the elimination of the port for the IAC on the plenum (won't affect anything since you already have an SD throttle body).

Or are we missing something?

 

so your saying no matter what plenum i use the 90-92 runners should bolt right up. maybe my slp runners are the ones that could be warped. but its ony on the drivers side there is a significant leak and loud, almost like a small gap or hole.

 

Could you possibly have your runners in the wrong positions.

 

Take em off and check your gaskets. I have done/seen a gasket slip enough that when bolted up it *almost* looks correct but its not even close. Then check to ensure that you don't have the runners mixed up like mentioned in the last post. Pay attention to the ports,ect when bolting the runners back up to make sure EGR,ect matches from plenum to runner to base,ect and take the time to really watch that a gasket doesn't get bumped off.

 

I don't know about the MAF plenums, but the SDs have little tangs that keep them from slipping.

I could see how if a piece of the old one was left in the hole, it would prevent the gasket from sealing properly as the piece of plastic would prevent part of the gasket from coming in contact with the metal surface.

 

is it possible i have the runners on the wrong side like i driver on pass. and passanger on drivers side. they could be flip flopped.

 

VERY possible... They will bolt up and appear to work but upon closer inspection, they will look "off". Not sure if they will leak though (I'm guessing its possible).

 

Hey quick question, im going with an 89 TPI set up, i bought SLP runners. I shouldnt have a problem using the stock runner bolt (stud) that goes on the passenger side runner first bottom one on the right. Im going with an 87 non serp belt system and i need that stud to mount the runner but also have the Alternator bracket bolt to the stud. P.S i went with 89 tpi to avoid the cold start injector set up

 

you guys are right , i installed the lingenfelter runners on the opposite sides, and got a major vacuum leak on the drivers side. the small tube will sit well below the plenum, and the steady leak will be heard.

 

don't feel bad, I've done it before, I just caught it beforehand (it didn't look quite right)..

 

ok so i checked the runners again, and still a major leak, the runners are on right, correct me if im wrong, the driverside has the hole plugged and the pass. side has the small hole that is open (90-92). could it leak from the egr, or maybe its leaking from the manifold where it bolts to the runner, it looks like the manifold has been ported slightly. i dont know and my car is running like ****. help.

 

loosen everything up and retighten gradually. I did this once and ended up having the car towed to the dealer where the tech simply loosened and tightened the runners.

 

Really?..... huh.

 

i tried that already, im going to give it another shot if not then the stockers are going back on thanks.

 

if you spray wd 40 on the intake gaskets (with engine running) the engine will i believe bog down and that's where your leak is... also if you have a torch u can use the gas to do it too but it will raise the rpm