Pre-vanos manifold install

[pamato]

So I finished the install tonight along with new spark plugs, new valve cover gaskets, new valley pan, new ccv, new intake manifold gaskets and new rear and front gaskets for the intake manifold. I drained the coolant and refilled. Top off with quart of oil. Started her up and it idles so bad. After the car got some coolant/water into the block, it ran a little better. On initial startup, the car revs up to 5000 rpms and stays there for 3-5 seconds, then it drops down to 500 rpms. It sounds like it is back firing in the intake manifold or it is missfiring. Not sure. I went back and checked all of the sensors and bolts. Everything seems to be torqued down. I am at a loss.

I have a dinan TB, mass meter and air flow meter, stage 4 software and exhaust. I was planning to have the Dinan stage 5 software installed and tuned on the dyno. But it seems as if there is more to my issue than an air/fueul issue.

Any help would be appreciated.

Paul

[dinan e39]

it's definitley not a software issue. i had the exact same thing done before i installed the stage 5 software and had no issues. the stg 5 software merely maximizes the air/fuel mixture with the new intake. it sounds like an intake leak somewhere but that's just a guess.

[Orxan4ik]

it's definitley not a software issue. i had the exact same thing done before i installed the stage 5 software and had no issues. the stg 5 software merely maximizes the air/fuel mixture with the new intake. it sounds like an intake leak somewhere but that's just a guess.

i think so too. its definetely an vacuum leak, u did so much stuff with gaskets, its gotta be smthn to with an unmetered air coming in, either thru vc gaskets, ccv or intake manifold

[pamato]

That is what I am afraid of. I did so much that it is hard to trace it back. I guess this weekend, I will remove everything and retorqe it. It shouldn't matter that the ccv is different on the prevanos and the vanos intake manifold.

[pamato]

Any idea how I can trace it without removing everything, it is difficult to keep the car running because the idle is so rough, it would be hard to follow vacuum leak.

[pamato]

dinan e39, when you installed the pre-vanos intake manifold, did you buy a new ccv or use your old ccv off of the vanos intake manifold. I am thinking maybe I didn't plug a hole in the back of the CCV. The old intake manifold does over the oil over-flow that runs through the middle of it.

My car is running so rough at idle, it must be a huge vacuum leak.

[PutterMcGavin]

I'm going to agree about the air leak somewhere...

I put the pre-VANOS manifold on my car and it started perfectly the first time...

I swapped the CCV from my old manifold to my new one. The CCV was only 6k old so it was a no brainer.

Couple ideas:

- The CCV is the same part for VANOS and non-VANOS cars however the M60's had a different (by part #) CCV. So if your manifold is from an M60 engine that might be (but probably isn't) your problem.

- The CCV off the old manifold could also be gone. Is there any smoke at startup? Any oil in the manifold itself near the TB?

- Maybe a gasket fell "out" while you were lining up the manifold?

- You make sure all the connections on the bottom of the intake elbow before the TB are correct?

- Check the connections at the back of the CCV, there should be two if I remember correctly on the top and one at the bottom with a spring. Are they connected to the correct place?

- The long pipe that connects to the CCV on the bottom might be a place of concern. the rubber tubing that connected it towards the front of the engine had developed some major cracks which probably let air into my CCV and blew it. Here is a pic of the crack and my "solution." I almost overlooked this and noticed it at the last minute and was glad I did!

http://i7.photobucket.com/albums/y254/PutterMcGavin/CCVBlow014.jpg



Good luck!

[dinan e39]

pamato,

i replaced everything behind, inside, underneath and in front of the manifold. i figured i only wanted to do this once while i owned the car. i'm going to sell the car next year and didn't want anything to come back and haunt me.
it could be a pinched gasket somewhere or a piece that was broken when it was flexed or moved due to being brittle. it gets hot under there and drys all those little gadgets out. good luck.


dinan e39, when you installed the pre-vanos intake manifold, did you buy a new ccv or use your old ccv off of the vanos intake manifold. I am thinking maybe I didn't plug a hole in the back of the CCV. The old intake manifold does over the oil over-flow that runs through the middle of it.

My car is running so rough at idle, it must be a huge vacuum leak.

[BKphoto]

have it smoke tested...

[pamato]

Thanks for all of the ideas. I replaced the CCV and all of the connections, o-rings, gaskets in the back and front and underneath the manifold, plus the the pipe in your picture too. I put new orings on the coolant pipes that run over the valley pan also. When putting my hand on the back of the manifold and using a mirror, everything feels secure.

I think I might have forgot to put the gasket back on throttle body. I bought a new one and found it this morning in the box with all of the new parts. After work today, I will check that and will install the new TB gasket and continue to check everything out with the last resort being to pull the manifold out again.

Thanks for the ideas. Keep them coming. I will keep everyone updated.

Paul

[pamato]

Found the vacuum leak. The prevanos intake manifold has a sensor toward the front on the passenger side. I inadvertantly removed it prior to placing it on the car thinking that I would replace it with my sensor. Well, my intake manifold doesn't have this sensor. Jusy an FYI if you do ths mod. The car is running, but I finished late. I will take it our for a spin tomorrow.
Paul

[razahyde]

the gaskets underneath the manifold have to be replaced in a specific order. if you dont bolt the manifold downt he right way your car will leak air as it is now. you have a leak in the intake manifold.s spray brake cleaner down near the intake ports. if cars revs go up then you know the problem, im pretty sure this is what it is. search and find my thread concerning this issue. i had it for like 2 months before i figured out whats up.

[BlackSapphire]

the gaskets underneath the manifold have to be replaced in a specific order. if you dont bolt the manifold downt he right way your car will leak air as it is now. you have a leak in the intake manifold.s spray brake cleaner down near the intake ports. if cars revs go up then you know the problem, im pretty sure this is what it is. search and find my thread concerning this issue. i had it for like 2 months before i figured out whats up.

Raza, he said he found the leak bro - 2 hrs before you posted this.

[nightkrawler]

the gaskets underneath the manifold have to be replaced in a specific order..

gaskets dont have to installed in any specific order, the manifold should be torqued in a specific order though. start at the middle of the manifold and work your way to the outsides.

[pamato]

Thanks for the help everyone. I found the leak. As far as I know, there isn't anymore leaks.

paul

[franka]

So how does it run now with the bigger manifold?

[pamato]

Everyday driveability is still the same, but the rpms rev faster and it has more umph at the higher end. All in all, I would do it again. I dynoed the car on Saturday. I can't upload the graphs because I don't have the software to read the dyno charts. I had him burn graphs onto a CD not knowing that I don't have the software to read it.

In July 2006, I dynoed the car with Dinan TB, MAFS, CAI, Stage 4 SW and remus exhaust. The best dyno was 255 HP and 276 ft-lbs. I felt a bit disappointed.

This past saturday, I dynoed the car with Dinan TB, MAFS, CAI Stage 4 SW, pre-vanos manifold and Remus exhaust. The best dyno was 276 HP and 297 ft-lbs. I am a bit surprised.

I think when I did the original dyno, the car was running hot and didn't perform up to its potential. With all things considered, yes the car is faster, no I don't notice the loss of low end torque, yes I notice the car climbs RPMs faster, yes the mid range torque feels stronger.

The air/fuel ratio is 14:1 at the top end of the torque curve and drops to 12:1 on the way down the torque curve.

I would rate this as a must do. I am not sure if the Dinan stage 5 software can improve my results much. What do you guys think?

Paul