Nemesis280zx

When we got back from the Cali trip I had to change the exhaust/intake manifold gasket. I ended up doing it and put everything back, tightened her back up, and the car started running weird, different. The motor sounds and drives different than before. When I have the car going 40 for example, I would press the gas all the way down and the car would bog or stutter quickly, then in the morning when I started the car up and started driving, when I give it gas the motor starts to stumble, but only for a second, the car idles fine and drives fine, it seems to have the same power as before, it just drives weird. Also the flow off is not as loud anymore. Before it used to blow off loud in first and now you can barely here it. It boosts the same as before(15psi.) and the fuel pressure is the same too. I dont know what to do, I checked leaks, but dont see anything out of the ordinary. Need some help. Thanks

NismoPick

Vacuum hose leak would be my first guess... also timing, manifold gasket not sealing tight, loose sensor connection / wire... pretty much anything you touched you need to carefully check again.

snwbrderphat540

yeah sounds vacumme/boost leak related to me to. make sure the manifold is all nice and tight every where adn check teh hoses, some might be broke or just left off. and check teh timing to though i doubt you screwed with it but thats a fast easy FREE thing to do, if you have a timing light, so basically, everything nismo said cuase he is a thief and has said stuff i have right after my post jsut recently so now im gonna do it, LOOK AT ME LOOK AT ME!!!!

SHADY280

as i always say, go get a can of brakleen and carefully spray the engine methodically. when the engine speeds up, that is your vacuum leak, and in your case also boost leak.

Nemesis280zx

I did to that spraying the motor, but nothing happened. The car also has no weird idle, idles normal. Hey your the guy from Canada, remember I had that black 280zx when I met you at that car wash in Cali. Well I'll try again to find something today. Thanks

NismoPick

That was you?! Dah... I was at the hotel. I shoulda come along w/ Shady & Bleach that night.

duowing

Ok this is a stretch, but it could be your ignition module and the timing just worked out that it crapped out on you. My car did this, timing was fine, the thing was running fine one day, then it ran like complete crap. I changed the AFM, the car ran really good again. I turned it of came back an hour later it ran fine. Next day I start the car up it runs like hell, but then the car would warm up and it ran better.

lifegrddude

It could be a collapsing vacuum hose. I had that happen to me just recently with my wastegate signal line, and a few old lines to the manifold. My blow off didn't vent, and my wastegate wasn't opening. I replaced the lines and everything is bueno.

Nemesis280zx

Well I figured out the problem. The people at the store gave me the wrong gasket, I didnt notice it but it was for a carburated (i dont know if thats the right spelling, oh well) z. I got the right one and I'm putting it on right now, I'll let you guys now how it goes. Thanks alot for the help, appreciate it.

SHADY280

hahahahah i remeber you too nemesis. you parked next to rod moyes at the show, we sat next to each other as well.

NismoPick

Oh snap! This was you?

SHADY280

that was him!!! thing sounds awesome coming down the road.

snwbrderphat540

i like the beefy tire look. doesnt look like the tires are uuber wide just some - offset to them, stilll. i do like

NismoPick

Yeah... I was admiring those meats at the MSA show.

So Nemesis, you get the gasket changed?

RodMoyes

You were parked next to me at MSA...


Rod.

frank280zx

haha and you where on the autox aswel !

Nemesis280zx

Yeah I remember you, both our cars were black on black, looked good. Yeah that was me, and yeah I was at the autox race too, that was fun. Well I enede doing the gasket for the third time yesterday and finally got it on right and now the car is fine sounds good, just it still seems to drive weird. It doesnt boost like it did and the blow off valve is really quite not. I guess I'm gonna try changing all the vacuum lines, see what happens then. I dont know what else it couls be. Yesterday I took off in 3rd gear and it took a while to boost to 18psi. usually it goes to where I have set it wuick, but not now. First gear is really slow now too, before I used to get through 1st gear quick. Well let me know what you guys think. Thanks again.

duowing

Run some seafoam through your vacuum lines. At least when it burns out, you'll be able to see if you still have any exhaust leaks. Check your timing, check all your connectors too. Maybe you switched a connector or two and that's causing problems? Or something got crap in it?

NismoPick

Getting seafoam in & out of all the vac lines would prolly take A LONG TIME.

ToxicZ

I bet it's gasket leak. I just got my head ported and bored out the intake #1 port on gasket a bit too much. Makes warmin up the car a bit more time consuming.

Gettin the proper gasket should fix ya up real good.

duowing

Well more or less I didn't mean you have to get the seafoam through all the vacuum lines, I just meant get it in one that will get it into the intake quickly so they you can see if there's any exhaust related leaks.

Nemesis280zx

Tomorrow I'm going to the shop where my brother works and we are going to check the timing and then we are gonn hook it up to a smoke machine to see if any smoke leaks out anywhere. I know for sure theres no exhaust leak, the gasket was good, good seal. I ran it at the track on Saturday and this is how bad my problem is, my cars best time was a 12.9 and it ran a 14.9, 2sec. slower. I need to fix this so baaaadddd!!! I'll keep you posted tomorrow on what we figure out. Thanks.

Nemesis280zx

Well we didnt find any leaks and timing is fine. The only thing I found is that theres a nut that holds the turbo to the exhaust manifold, well it's backed out almost all the way. I'm thinking this is where my problem is. I will try to tighten it tomorrow, but I think I have to take out the intake manifold again just to get to it. I'll figure something out. Keep you posted

duowing

Well it is possible that could be causing a leak. I mean since it wouldn't be tightened all the way in that corner where the turbo mounts and also you may not notice it until you get it going anyway, as in not enough exhaust pressure going through to push it's way out through the leak maybe?

Nemesis280zx

Whats up guys, heres the good news, I was able to tighten that nut down, but the bad news is it didnt help anything. It still runs the same, it still takes a while to boost. We put it on a smok machine, but that didnt reveal any leaks anywhere. I dont know what else to do other than to take it to the shop and have them run a diagnostics check on it, its about 86 dollars, maybe they can figure out whats wrong with it, since I have no clue.