clint240sx

iTrader: (2)

Hey 4th gen bros....I have a huge issue. I currently have the 4th gen upper and lower manifold (stock) on my 1999 Nissan Maxima. I took them out to start my 00vi setup. When I found out I couldn't do to a few missing parts...I put the stock parts back on. I had to cut 3 hoses, but went and bought new hoses to replace them (they fit, i made sure)

Now when I start my car it runs for about 5 or 6 seconds then shuts off. And I smell a good amount of fuel burning. I'm obviously getting fuel, but something is not mixing to run like normal. I am decent with mechanical stuff...but it's just not making sense.

Anybody dealt with this before? I need my car running!

clint240sx

iTrader: (2)

And I'm more than likely sure it's not the MAF, I've left it alone and made sure not to tamper with it.

aackshun

iTrader: (3)

Any codes? hows the idle? Can you keep it alive at all by playing with the throttle?

What hoses did you fool with/have to replace?

FallenOne

iTrader: (17)

Listen For Vaccum Leak.

Unplug MAF.

maxgtr2000

iTrader: (29)

Make sure everything is plugged back up, if you are not getting any codes it could be an iacv valve connection issue or fuel pressure issue. Double check your fpr vacuum connection.

cashoit

Check hose connections on UIM. U sure u put everything back on? Did u replace all gaskets when u reinstalled everythin. Sounds like a vacuum leak to me

clint240sx

iTrader: (2)

We believe it is a Vacuum leak...however I've unbolted and bolted the stock parts back up, and by "we" 5 guys that also know about cars and what not....nobody has been able to figure it out. Honestly...we believe the issue is so minor, but having no luck.

The car will stay alive by playing with the throttle.

99sagelimited

I was in the same situation a month ago. I took my upper and lower manifolds off to replace gaskets and ended up with a large vacuum leak when all was said and done. Mine turned out to be a bent fuel rail that caused the injectors to not seat properly. Do you hear a hissing? If you do, does it go away when you rev the engine? If you have access to a code reader that has live data, you should look at the fuel trims too. If you have a vacuum leak, the fuel trims will be >5-10% meaning the computer is adding fuel to account for the un-metered air and keep the mixture correct.

If the engine is dying quickly, that tells me the vacuum leak is large. Mine would run for several minutes before sputtering out. Did you replace any gaskets or just re-use the old ones? Did you tighten everything per the FSM? Sorry if you answered those questions already.

FallenOne

iTrader: (17)

Did you try what I said and Pull the Codes or unplug the MAF and start the car?

Somebody smokes, give them a pack of cigarettes and start blowing the smoke into the engine bay, get a good light and follow the smoke.

If there is no vaccum leak, which honestly.. If there was the engine would most likely Race Not Die, You need to start with the coils, pull them one by one, than move onto the fuel system.

But as im sitting here I remember my first 00VI swap. Its either your EGR, or your Throttle Body.

clint240sx

iTrader: (2)

Thanks for your input bro, but I won't let anybody smoke around my engine

Yeah, I need to mess with the coils...i've already pulled them out, but i'll give them another look. And as far as the fuel system goes, I haven't touched it except for removing one hose, but I'm 100% sure I put it back on right. So that's not an issue. I'll look at my EGR...but I haven't messed with it either except for when I unbolted it from the UIM, I've rebolted the same way.

FallenOne

iTrader: (17)

Be wary of the EGR getting bolted back down properly and the TB. Also Try RTV'ing your TB gasket.

clint240sx

iTrader: (2)

Noob question: What happens if it isn't bolted down correctly? I tightened it pretty good. Had a friend watch me do it to make sure it was proper.

FallenOne

iTrader: (17)

Just do it again.

Honestly. Pull off the Entire Upper Again and redo it all. Seriously its not that hard. You dont need to go crazy with all the connections just ReSeat the Manifold.

maxed_out_99

what about that one vacuum line under the manifold? its real easy to miss and would cause your problem for sure