m50 manifold swap big time issues

[diesekte]

SO I got the car with an OBDII M52 with an M50 manifold on the car, with crank case venting just to atmosphere. I wanted to retain CCV so I went the M50manifold.com kit way. The car ran ok before I did anything to it. It has headers so there is no SAP. There also is no vacuum canister or hard plastic vacuum line like it says in the m50manifold.com instructions. The BMW connector that plugs into the underside of the manifold....the little nipple coming off of it was connected to (I believe) the FPR at the back of the fuel rail, and the little vacuum connector on the manifold itself was capped. There was no IAT at all - one part of the wiring harness bifurcated and one limb went to MAF and one limb has nothing attached.

After many many many hours of frustration, I found this thread:

http://www.r3vlimited.com/board/showthread.php?t=256901

I have my vacuum set up exactly like that. BMW connector has a small vacuum hose that goes to a "T", one end is connected to FPR on the fuel rail and the other end is connected to the small vacuum nipple at the back of the manifold (that was previously plugged). The large vacuum port on the manifold goes to a black/white check valve then to the brake booster. One thing that may be important is in the m50manifold.com instructions, they used the "black label" ICV, but my car previously had the "green label" ICV so I switched them to match the instructions. I still don't have IAT at all....my intake boot only has 1 port and that is being used to go to the ICV - however this was the set up before when it was running alright.

The car started up but runs like absolute shit. It still sounds like a chevy 350 with an aggressive cam. I was able to drive it around the block but it something is definitely not right here. It felt like it wanted to stall, and sometimes when I would give it gas it would hesitate for a second before moving.

Can someone please please lend me a hand? I'm about 10 hours into this thing and about to drive my car off a bridge, if I can even get it to run long enough to do that...

Thanks

[e30austin]

Did you make sure the little plastic connector for the ICV (lovingly referred to as the "turkey neck") hasn't come out of the back of the manifold? Good throttle body gasket? Intake gaskets good?

[diesekte]

Also is there a chance that it is idling rough even with things hooked up properly bc it was driving around with a vacuum leak with crank case venting to atmosphere for so long?

My dipstick also wiggles around, could a significant enough leak be coming from there? Oring looks fine. How so I get it seated more tightly? Rubber mallet?

[diesekte]

Well I seem to have solved the vacuum leak.

1) that POS BMW connector underneath the manifold...pushed it in tight and epoxied the hell out of it
2) tightened everything...again
3) Injector closest to the firewall had lost its pintle cap, spacer, and o-ring. Luckily I had no-lint rags shoved in the engine when I was doing everything. I found the pieces of it outside the engine. I replaced all pintle caps and o-rings on the injectors
4) Put a new o-ring on the dipstick. The bracket can't connect to anything now with the CCV in the way so I just zip tied it to a bunch of stuff to try and keep it steady. Anyone have a better solution? I pushed it down as far as it will go and it never gets tight
5) IAT needed to be screwed in a little more

Started the car up and it went to about 2000 RPM for a few seconds, then came right down and idled at 750. I went around the block and it seems to pull a little bit better. The lopey sound is more or less gone, though it still does it occasionally for a second then smooths out. The car has only been run for a few minutes since reassembly.

Now this is my last problem/obstacle. Does anyone have a definite solution to the photo below? The fuel rail holes now seem just slightly off of the manifold holes. On the m50manifold instructions, it looks like the 3 little adapter brackets they provide are to be installed "longways" (parallel to the long axis of the car). The only way I could see those working is perpendicular to the long axis of the car? So my two options for getting the rail secured are:
1) push the rail over to the drivers side and just screw it to the manifold as is. This is how it was before I did anything to it. The problems with that are that the threads on the manifold are starting to get stripped since the axis of the screw is a little bit off and it ends up "pulling" the rail over. Also the injectors don't seem to be optimally seated.
2) push the rail to the passenger's side and use the little 2 hole brackets. This solution suffers from the same problems as #1

Pic for reference:

[superunknown]

I'm facing the same problem and been going through forums to find a solution. I have an S50 usdm running on a 52 head and a 50 intake manifold. The bigger ccv hose is just dangling to the atmosphere where the smaller one is connected to the icv connector underneath the intake. My dipstick does not have any secondary inlet and the worst part is that I found out there's totally no vacuum suction at all when I tested to open the oil cap when idle. Someone please help me out here. Many thanks!

[Mwishlist]

Well I seem to have solved the vacuum leak.


Now this is my last problem/obstacle. Does anyone have a definite solution to the photo below? The fuel rail holes now seem just slightly off of the manifold holes. On the m50manifold instructions, it looks like the 3 little adapter brackets they provide are to be installed "longways" (parallel to the long axis of the car). The only way I could see those working is perpendicular to the long axis of the car? So my two options for getting the rail secured are:
1) push the rail over to the drivers side and just screw it to the manifold as is. This is how it was before I did anything to it. The problems with that are that the threads on the manifold are starting to get stripped since the axis of the screw is a little bit off and it ends up "pulling" the rail over. Also the injectors don't seem to be optimally seated.
2) push the rail to the passenger's side and use the little 2 hole brackets. This solution suffers from the same problems as #1

Pic for reference:

I can't help overall, but the adapters are only there to be able to fit the fuel rail beauty cover. They aren't there to correct the fuel rail itself.

[poopin04]

Ever find a solution? Running into the same issue with my OBD1 s52 swap.

[Sh3rpak!ng]

Not sure if this helps you guys, but I am running the m50 manifold with the m50 fuel rail (even though I'm OBD2). IIRC, there were some tabs underneath the fuel rail that had to be bent/cut off that interfered in some places, but otherwise it fit without a problem. Injectors are all lined up properly. If you think about it, that fuel rail is meant to be bolted to the IM exactly as you see in the picture - that's how it would've been mounted from the factory.

[Sh3rpak!ng]

I'm facing the same problem and been going through forums to find a solution. I have an S50 usdm running on a 52 head and a 50 intake manifold. The bigger ccv hose is just dangling to the atmosphere where the smaller one is connected to the icv connector underneath the intake. My dipstick does not have any secondary inlet and the worst part is that I found out there's totally no vacuum suction at all when I tested to open the oil cap when idle. Someone please help me out here. Many thanks!

Think about it... you have a huge open vent on the crankcase (the bigger dangling CCV hose), so even if you were pulling vacuum, you wouldn't feel it since you left that hose open. Also, it sounds like you've introduced a vacuum leak. Again, think about it: you have the smaller CCV hose connected to the ICV connector aka the intake, and you have that larger CCV hose open to atmosphere = so in essence, you've connected your larger ccv hose to the intake after the MAF - you have an unmetered source of air intake which is bad.

If you're going to vent the CCV to the atmosphere, the crank case has to be completely isolated from the intake. If you're going to connect any of the CCV to the intake, the whole system must be closed to avoid a vacuum leak.

For NA cars, open CCV to the atmosphere is fine (it'll just smell and maybe drip oil out the tube)