Problem After Installing 505zoom Intake Manifold

[NCoppersmith]

Ok, finished my "build" in that all the parts are installed and the engine starts. As soon as you hit the key she starts right up and pulls a good 20hg of vacuum, which rapidly detoriates to about 10 with the needle pinging back and forth so rapidly you can't actually see it due to motion blur. (Innovate Mechanical G3 Vacuum/Boost gauge directly attached to IM) This is with the 505zoom aluminum intake manifold installed, stock fuel rail and injectors, no EMS. The engine idles incredibly rough with it picking up and almost dying pretty much constantly. It sounds like there's a leak right either at the fuel return regulator or the PCV. I know it's not the PCV, but for the life of me I can't figure out where it is. I have checked and rechecked the entire intake system from the airfilter all the way to the manifold, then traced down every connection. Yes, I've tried using carb cleaner at junction points along the entire manifold, injector tips, you name it, to no effect. (incidently a 10hg leak is one massive leak, to lose that much vacuum I'd have to have a bajillion tiny leaks from the whole system, some of which I'd had to have found and fixed by now)

My scan tool shows the MAF sensor as wildly out of spec (more than double) but swapping it out with my known good P5 MAF gives the same results. It kinda sounds like it might be the fuel return regulator, as that's close to the noise, but I haven't tested that yet. Long Term fuel trim never changes, Short term fuel trim looks like its within normal ranges. For some reason my TPS sensor always shows 10% at idle, the sensor tests correctly, so I wonder if maybe the throttle body is bad/leaking, but I can't tell from where.

Anyone have any direction from replacing manifolds that I might have run into? I could post a video of the engine trying to idle if anyone needs a good dose of depression. :b

 

[CHIQLES]

I want to know what others have experinced with that mani.

 

[KrayzieFox]

Kinda sounds like the manifold didn't seal very well with the head. You sure you don't have a leak there? You used a new gasket right?

 

[808MP5]

My TPS always reads 10% also when i'm not pressing the throttle so that might eliminate a probable cause.... well that's if a 10% reading is the norm

 

[Dpwhitehead1]

i know the answer. this is 100% your issue-


get a new IM gasket, USE RTV-BLUE is fine. you have a terrible leak at the mani. trust me, i JUST went through this. and it sound nearly identical.

also, the injector o rings they could be not sealed totally. DID you use the spacers(plastic spacers for the fuel rail bolts)?.. if you did, take them out, and crank the bolts down further.

 

[StealthWyvern]

i know the answer. this is 100% your issue-


get a new IM gasket, USE RTV-BLUE is fine. you have a terrible leak at the mani. trust me, i JUST went through this. and it sound nearly identical.

also, the injector o rings they could be not sealed totally. DID you use the spacers(plastic spacers for the fuel rail bolts)?.. if you did, take them out, and crank the bolts down further.

(uhm) Doesn't that "spacer" also contain the seal as our stock injectors dont use o-rings. So how would they seal with no seal?

 

[Dpwhitehead1]

(uhm) Doesn't that "spacer" also contain the seal as our stock injectors dont use o-rings. So how would they seal with no seal?

ALL plastic spacer. circular in shape, located on the top of the fuel rail, where you put the BOLTS THROUGH TO TIGHTEN THE RAIL TO THE MANIFOLD...


do you understand that now? i dont mean the injector rings.

 

[Dpwhitehead1]

omg that sounded douchey.. i didn't mean to be that way, sorry!

 

[StealthWyvern]

ALL plastic spacer. circular in shape, located on the top of the fuel rail, where you put the BOLTS THROUGH TO TIGHTEN THE RAIL TO THE MANIFOLD...


do you understand that now? i dont mean the injector rings.

omg that sounded douchey.. i didn't mean to be that way, sorry!

HAHA no big deal. I forgot all about those spacers that go inbetwen the rail and the intake manifold

 

[NCoppersmith]

No, it is 100% not the gasket (well, I doubt it anyway). On Friday night I pulled the manifold off just to double check it. I used a brand new napa felpro gasket with the beaded side facing the manifold. I edged it out with black RTV. A mechanic coworker came by to double check it and we though that maybe the little lip on the head the juts out over the runners was preventing a good seal, so I dremeled back some of the aluminum on the manifold to make sure it wasn't keeping the surfaces from mating properly.

I did use the black spacers on the fuel rail, so it's possible that it's leaking around the injectors. Without those spacers is it possible to damage the injectors or fuel rail by overtightening?

To add insult to injury, the two middle head bolts by the manifold protrude so far that they actually hit the IM and I snapped the bottom of the bolt off trying to tighten it, failing to realize that it was hitting that. <sigh> I'm a serious contender for the world's unluckiest mechanic...

 

[StealthWyvern]

I doubt your injectors leak that bad... mine leaked so fast that during a boost test it would go from 12psi down to 0 before i could get from the driver side headlight to the passenger side tire. I did not have those types of issues your having along with 3 out of 4 couples having tears in them as well.

 

[SeR_Cyclops]

I just got my 505zoom manifold installed last night, I havnt cranked the car yet due to problems with the EGR but ill let you know once I get it finished up.

 

[Dpwhitehead1]

you put the gasket on backwards. the beaded side goes towards themanifold. then you use rtv on the entire front and back.. that's what i did. ALSO, you have to tighten the bolts in sequence. middle, left, right, far left, far right.

it COULD cause damage if you tighten too much, but i'll put it this way, with both the 440 injectors and the stock ones, on the fuel rail mount, and IM mount(where the spacers go) are touching.

 

[SeR_Cyclops]

It also could be hitting on the casting mark on the head mine was really close. Mine has a large VAC leak, when i start the car it starts up and dies. I took the mani off and I am going to use more RTV and make sure the manifold is not hitting the casting mark.

 

[SeR_Cyclops]

Here are pics where mine is hitting the casting marks. Sorry the pics are as good as i could get. On all of the other runners it sets below the milled out area that Mazda machined for the stock manifold.

The machined area should be above the flange instead mine is sitting on the casting mark. So tomorrow I have to get a file or dremel and fix it. Does anyone have any ideas on that?

 

[NCoppersmith]

[QUOTE with the beaded side facing the manifold. /QUOTE] Pretty sure this is what you mean, right? Beaded side goes against the manifold, aka pointing toward the back of the car, not the front.

Also, the casting mark on the head is what I was referring to as the lip, I dremeled back the manifold to make sure it wasn't hitting that.

I'll pull the IM again this morning and try RTV'ing the engine side...I'm not optimistic about that fixing it but I don't have anything to lose at this point. If that fails I'll pull the fuel rail spacers and try torquing it down without them.

 

[NCoppersmith]

Fixed it

Boostedprotegelx gets the prize, cookie, medal, and a pony. It was the number 2 injector o-ring, hitting that hard with carb cleaner almost made the engine die. Pulled the spacers when reinstalling and she runs like a champ now, a small leak somewhere along the firewall it sounds like, but it pulls 19hg of vacuum at idle now and purrs like a kitten. (actually roars like a tiger with that infernal iON exhaust but still...)

 

[StealthWyvern]

Boostedprotegelx gets the prize, cookie, medal, and a pony. It was the number 2 injector o-ring, hitting that hard with carb cleaner almost made the engine die. Pulled the spacers when reinstalling and she runs like a champ now, a small leak somewhere along the firewall it sounds like, but it pulls 19hg of vacuum at idle now and purrs like a kitten. (actually roars like a tiger with that infernal iON exhaust but still...)

must of been one HUGE ass leak man. Im telling you all 4 of mine leaked bad and the little seals on them were so hard I thought they were plastic. Its amazing that only 1 leak caused you that much pain.

 

[Dpwhitehead1]

Yay

 

[SeR_Cyclops]

Mine was leaking on the head, I actually took some of the manifold off where it wouldn't hit and before my car wouldn't even run. Now its pulling about 14 inches of merc and its idling real rough. I'm gonna get new injector O-rings and take out the spacers. It seems like the fuel rail is leaking. I took off the fuel rail (Perrin) and i didn't see it but my buddy said it had some gunk on the back side of it where it was spewing out. I didn't see this but he knows quite a bit about cars but he wiped it off before I could see it.