4th Gen Intake Manifold removal

[1997i30]

I was trying to chase a P0400 EGR problem which I think is related to a hesitation problem I am having. It sounds like a large bass sound each time the hesitation hits and the RPM lowers a bit during a stop sign in D or when put into R. Anyway, I removed the EGR valve and cleaned that filthy EGR tube. When I looked into the manifold from the IACV mound hole it was extemely black in there...I going to put it off, but I noticed an oil leak coming from the right side valve cover so I decided to take the intake manifold off tonight....Does anyone have any suggestion while the intake manifold is out if anything else should be changed or looked at? Just hoping the P0400 code and the wierd hesitation/surge will go away after I put everthing back...thank you

[Presscott707]

i just change both the upper and lower intake gaskets and i cleaned out the upper and lower intake and change the valve cover gaskets and the car runs smooth. and my egr was all gunk up to , but i cleaned it all out. you should change the valve cover though for sure.

[1997i30]

Thanks Presscott707 you definetly have my respect cleaning up that intake! what did you use to clean it up? All that carbon build up in there is so stubborn. Did you happen to change the 6 spark plug gromets? if so, how did you get the old one's off? I don't see where I can get any tool in there to pry without scratching it up since it's aluminum. You know if I was sitting on a pot of gold I would like to change the Injectors, coil packs, put headers on now with all that exposed....

[Presscott707]

after i took everything off the intake i used one whole can of carberator cleaner to loosen it all up and then i wiped it up where i could and then washed it out with water. then let it all sit for a day in the sun to dry. i also wiped out the intake side of the head. it was all preatty gunked up. how miles do you have on your A32 and what are you trying to do with it?

[1997i30]

I cleaned up as much as possible on the intake head side too, but could not actually get all the build up that I see around the two valves. I have 113k on mine right now...my plan was to do some exterior Cefiro coversion: lights, badges, grill, etc. Plan on being a highway cruiser in traffic so I went with an auto. Plan on lowering, rims, intake, exhaust. I'm just first hammering out all the neglected items on this old warhorse. Hey, did you ever change the spark plug grommets? and if yes, How did you do it??? I can't seem to get mine off. Thanks

[1997i30]

Nevermind..their pressed in there....I was able to pry them off with a very large flat head and carefully making sure the tip doesn't damage the moutning area...Going to my infiniti dealer to pick up the TB gasket($4.30), EGR tube gaskets($4.77each)...depressing it'll take them a whole week to an PCV valve($13.80), grommet ($13.40), and IACV gasket ($4.60)..I'm tempted to make my own IAVC gasket and getting the Fram PCV which my local parts store has ($4.99 vs. $13.80 and wait a week). When you took your lower intake manifold off I assume you had to take your injector's off too right? did you replace the injector O-rings with new one's when you put them back in? Thanks

[Presscott707]

no i reused them. only thing on the fuel system that i replaced was all the clamps because every time i try taking one off they would break. but removing the fuel rail was easy.

[NutriaforBreakfast]

What about the knock sensor? You could put a multimeter to itto check.

[1997i30]

I did put multi meter and it was withing spec, but I ended up replacing it a couple weeks ago, but it it' still doing it...big hesitation kick while it's in gear at a stop. No idea what it is..the last couple things I could think of is failing ignition coils, coolant temp sensor or air sensor, and I am now receiving a SES light code of 0446 which is evap, but I don't think the evap code446 could cause such a hard kicking hesitation like that...IIs is possible for a failing coil to make the car hesitate hard and then not kick up a SES light? Overall after all the work so far the engine is running really strong and my MPG is about 22 and best has been 25.

[NutriaforBreakfast]

I had a bad coil one time on my 95.

It would run fine on the highway at high speedsbut would run poorly on the street