Maxima Man

Hi Guys, I cleaned my throttle body and butterfly plates ( its a vg ) and I started it up and it had a 1500 rpm idle !! It did not just rev up to 1500 rpm when I started it, it stayed at 1500 rpms. UHHH..... I did try to adjust the Idle Air Contol Valve but the only difference I could tell is that when I turned the screw on way it had more hissing sound. The Idle varyed very little while turning the screw to both extremes!

What else can I do to remedy my problem Thanks Guys!!!!!

Greeny

iTrader: (43)

Try cleaning the iacv.......

Maxima Man

Would it being extremly dirty be the reason why it is not having an effect on Idle RPM's ?


Thanks ..............

Greeny

iTrader: (43)

Yeah...it could...Not sure though....It cant hurt to clean it..

Maxima Man

Any other Ideas Guys....................
Thanks !!!!

Greeny

iTrader: (43)

I high idle is also a sign of a vacuum leak......

Maxima Man

I do hear a hissing sound!

If someone could listen to there vg engine with no vacum leaks and tell me how much hissing I should hear that would be great!

I just recently replaced all the vacum lines

I thought I was sure they were all put on properly........... Should I have put some type of sealent on the hose connections ? I just pushed them on. Could that be my problem?

Greeny

iTrader: (43)

Naw...You do not need to put anything on them...you did it right...I would check ALL the vacuum lines,maybe one fell off or something...

96ItaliaSE

iTrader: (3)

yah something is hooked up half ***...retrace your steps youll find it....happens all the time

kcidmil

try the adjustment screw on the IACV. That's where my problem lay, it had somehow backed itself off over the course of a few months to the point that my idle was at 1500.

Greeny

iTrader: (43)

Read his first post...thoroughly....

kcidmil

reading is overated... I'm following Mr. Gone's footsteps

Harvs94max

iTrader: (5)

did u take the tb off? if so did u replace the gasket? otherwise retrace ur steps like others have stated

Wiking

So it goes... If idle was ok before TB cleanup, the leaking from gasket(s). IACV may jam, but why would it do at TB cleanup... Is IACV Envious?

Loco7

iTrader: (1)

my idle some days is at a 1000 and some days it jumps to 1500 and stays that way wither it be at start or after driving around for a while. you think it's a vacum line or something else?

Maxima Man

When I cleaned the throttle body I only removed the air ducting metal pice that leads air into the throttle body. I did not replace that gasket should I remove agian replace?

Would it screw the car up if i made my idle go down by adjusting the screw under the throttle pivots( you know the throttle cables connect to it, the other side of the TPS sensor )

Could my new vacum lines create more vacum on the system because they are not leaking anymore, and possibly cause something else in the system to start to leak a vacum?...........If so what should I susspect look for?

Thanks Guys.......!!!!!!!!

Wiking

All depends if it leaks or not. Got To Open Again, check seal still works. Add liquid gasket if necessary...

FSM has a hole in this adj. At least I've not found. IACV etc see: http://www.cardomain.com/ride/748507/4




Adjust: Check that flap screws are tight, adjust for minimum clearance (flaps should not touch TB.)

Tiny leak in the input hose to IACV may cause idle to roam to 1500rpm. Also if u take MAF connector off... But u did not touch IACV, did u?

Check out where these hoses are attached to the intake; goto Favorite Links:

mountainmax

I recently replaced my injectors and had the same thing happen when I started it back up. (I replaced all the fuel, vacuum, and coolant hoses as well). I think one of the steps in the FSM to troubleshoot this is to disconnect the solenoid at the IACV (or whatever it's called) to see if it's working. When I did that it immediately went to a normal idle, and it stayed normal when reconnected. It has worked fine since then. I think that it either got stuck or had a "logic problem" and needed to have the power removed while running to fix it....

SJC

Wiking

60k miles gallop fills TB & IACV with soot. The IACV stepper motor screw/valve eats its share. Will stick intermittently unless cleaned. Click to see.

Connector oxidation logic...

maxitech

iTrader: (7)

As stated above, make sure to check the MAF...Probably not the cause, but has similar symptoms.

Maxima Man

So should i just disconnect the stepper motor while the car is running and reconect?

I want to clean the stepper motor but I don't have any liquid gasket on hand!

Is it bad to adjust idle from the adj. screw in wikings post above?

Thanks Guys>>>>>>>>>>

vansskaterfreek

iTrader: (14)

take throtle body and air intake cleaner and spray it along where you took off parts where gaskets are needed, when engine revs higher, there is where your leak is.......i just did this and replaced all gaskets, now it runs smooth as hell and no more hissing sound!!!!

Wiking

1. U may do that, no magic in there. Helps only if your connector is oxidized.

2. I did not use any liquidseal - as the seals were ok. Stepper motor has rubber ring seal, open that one only with 3 phillips screws... no need to open the whole assy [4 hex bolts]. IF problems arise, tape it all around until get new rubber seal.

3. No its NOT 'idle adj screw'. Its initial flap setting screw. Typically no need to touch that one if setting is not worn out and flaps have started to touch the TB.

1 + 2 + 3 = First check all leaks out. Then adjuts idle as indicated in FSM: click http://www.cardomain.com/ride/748507/4 ...and see also the Favorite Links

Maxima Man

I took apart TB again and cleaned the little vacum line holes below the butterfly plates and I noticed the bottom of the butterfly plate was touching the bottom of the TB!

I then pulled the throttle cables up and noticed the adjustment screw had a little line cut into it from where the throttle cable spring thing comes down and rests on it ( It was worn down some ). I'm thinking it has worn the screw down and that is why the plates are touching the TB.

Should I adjust screw up a little bit? So they don't touch the TB anymore?

Thanks Guys

Maxima Man

Bumpppp......... Anyone?
Thanks

Wiking

As said, I have adjusted it to minimum possible clearance. (The more its open, the more air gets in, MAF input to ECU increases, ECU boosts injection = revs go up. On the other hand, touching flaps loosen the screwss...)

From idle adjustment: my adjustment lower limit never goes below 900rpm, dunno why o why. Adjustment itself is done ngine warm, ECU sw turned.

MAF gone bad? Measure before swapping.
see http://www.cardomain.com/ride/748507/1 ...page 9

Check this:
Nissan TSB NTB94-085.pdf; idle fluctuation due to filter.
TSB's see for http://maxima.theowensfamily.com/tsb

Maxima Man

Ok thanks wiking I looked into that info.

I cleaned my ivac and sealed it all back up and it ran pretty smooth but I still have some hissing.

My engine idle is pretty controlable now with a turn of the ivac screw

I have one Question still why does my car rev up so high when I just start it up in the mornings it revs up to 2000rpms and then slowly crawls back to 1500rpms then I put the AC on and it drops to 1300-1400rpms then after it gets warm it idles down to 900-1000 rpms while in park. I don't like making my transmission slow my engine down from such a high rpm to shift into drive just to leave the house in the mornings. Is there anything

I can do to reduce such a high start rpm (as soon as it starts it sits at 2000 rpms then slowly declines)?

Thanks sooo much guys

Wiking

1st. Seek out the airleak. Hoses, intake gasket leak. Around suspect areas, spray smtg. Some use gas, when sucked in, idle increases. Some use water or oil, when hits the leak, it blocks the leak temporarily, idle down.

After that, MAF.

Noogood but possible temp fix is to crimp airhose to IACV 50%.

Maxima Man

What parts of the car engine need a good gasket to remain under a vacum, I have checked my vac. hoses twice can't find problem with them. But the vacum hose that connects to the left rear part (looking at the front of car) of the intake manafold is not pushed on the black fitting very well. There is a crack on the hose that leads into the ivac but I think I sealed it up with liquid gasket pretty good. Any other vacum sealed parts to test with oil or gas?

P.S. I don't think my ivac hose is that flexable to be crimped 50% it is hard and stiff!

Thanks wiking !

Maxima Man

bump............

Alex_V

When your car is cold it increses idle speed to warm it up faster. no biggie.

~Alex

Sgibb

iTrader: (3)

Just tap the gas to rev it up a bit and it should go down... that always works for me

Wiking

My TPS works. No need for tricks...

Wiking

Bump: I am sleeping & snoring durin nighttime.

Hose should be rubber... if its not, buy... Do crimp only for tst purposes: if your startup 2k rpm still exhibits itself after that, then definitely airleak somewhere. Could be cracked upper/lower intake seal.

Any time excess air gets in, injection is increased to get adequate burn results = rpm shoots up.

Difference between cold&warm is also IACV air flap. Maybe its jammed? Dunno how bad flap effects, FSM tells its safety device for runoff idle... Read the IACV cleanup -page...

96ItaliaSE

iTrader: (3)

well to be honest on most nissan auto transmissions if you idles is off even just a touch (hot or cold) your shifts get real choppy...ever wonder why is shifts so yucky when its cold? if you dont belive me turn up your idle to about 1100 and go for a ride it stinks.

Wiking

News to me: 15minutes ago - Hi idle at 1500rpm, (both fans maximum, warm engine.)

Relays, no. Playin with EGRC temp sensor. Drops to normal 900. Take off, again, same problem.

My Hi idle problem was EGRC loose connector... (hmm. great idee: then bad sensor may do the same)

Maxima Man

Ok I am going to buy a new egrc and then make sure the plug makes contact,

Wiking what are those two black hoses that look like vacum lines for in the pic above?

So the only places that use a large gasket in the engine that could leak vacum are the manafold gaskets correct!?

Thanks a million!

vansskaterfreek

iTrader: (14)

my intake gaskets were cracked........
this is what it will probably look like....this is a pic of the upper intake manifold taken off (there is a gasket in between there and probably cracked also below this is another gasket mine wasnt cracked but yours might and you mind as well change it to help future problems)
as you can see some of my gasket is actually missing!!!!!! this was the problem.

this is the upper intake manifold



you also might want to replace vaccum hoses also....some will crack from age 50% of my hoses cracked while taking them off... i just got windsheild washer and vacum rubber hoses

Wiking

Yes definitely tst for intake gaskets, use/spray propane gas, water oil or whatever... Gaskets do age/brake, engine sucks em in...

Pic:
Off bent blk ign wires - for rear bank. U know, lots gimmicks have to be done to create smilin sunny pics, the go phot-o-shoppin...

With that price, u may buy 5 multimeters, instead learn to measure the the EGRC resistance; they dont break like that.

I once did brake my EGRC harness connector, thats why that was now loose.

"Normally" I open hood, first break smtg, then correct that and will be happy. Problem tends to be, the problem sist still tHere someWhere. Eh.

Maxima Man

How much does the gasket shown in the pic above cost ?

What does the gasket below that gasket cost?

I am going to try to spray some oil in the engine gasket to see if it slows the idle temporarily, I pinched the IVAC input hose to 50% flow and the idle did not change.

That tells me I have a vacum leak else where.

Thanks Guys !!