Hey guys my 89 VG max is missing, not a consistient miss but spuradic
And it has a stable 1500 rpm idle after start up but right when it is started it jumps up to 2000 rpms then slowly drops to 1500rpms.

Whats New?
Air filter
Fuel filter
Fuel injector cleaner (techron)
Spark plugs (Bosch) I now know
Spark plug wires
Distributer
IVAC cleaned
New Vacum hoses

What the heck is going on guys please help!

Thanks!!!

 

start with replacing the plugs with NGK

then report back

 

What's wrong with Bosch? Not that I am defending them, I have no experience here, this is an honest question.

 

they have been known to cause running problems on the maxima

 

Clean the MAF plug connection

 

For some reason the Bosch plugs deteriorate in this engine instead of working. Stick with NGK.

 

Ok guys I will change plugs to NGK !! I bought the bosch before I knew better!

Any ideas why I have a high idle !

Thanks guys keep posting......

 

High idle in 90% cases is due to a vacuum leak, i.e. repair the vacuum hoses (all of them). But I have also just discovered that if there is a loose contact in the lower TPS connector, the idle will be around 1400 and wont change by the IACV screw. Check and see.

 

What is the lower TPS connector I know where the TPS is located but I only know of one connector to it!

I replaced vacum hoses but I don't no what could be leaking!!

Keep Posting Guys!!

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

 

The TPS has two connectors: one rugged rubber coated on top and one grey plastic at 90° angle on the bottom (both facing the radiator). If you disconnect the bottom one at idle, the RPMs will go up and stay there regardless the IACV screw position.

 

Ok i will check it out

 

anymore ideas while I check on the above?

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

 

bump......

 

Have you done any of the suggested fixes????

If not then do some of them and then report back...

 

spray some air intake cleaner all round where the upper and lower intake manifolds meet......do this with the car running if your RPM increases..there is your leak..this is the problem i had on my VG and now it is fixed!!!



hereis the upper intake manifold upside down





this is right below it




mine had a cracked gasket and that was the cause of the vaccum leak (high idle)