91 z32 tt, running very poorly help please

[figo_madrid04]

ive got a 91 300zx tt, very well kept and runs well, however, i was driving today and i down shifted from 4th gear to 2nd at about 40 mph and i built boost, however as i was accelerating i heard a lil pop, prob a misfire. anways , i quickly came to a stop and the engine was making a rumbling niose. i let the car run for a while and at time it would make a sound like its knocking but then it would disapear. i cautiously drove the Z home, it made the same noises and had diffculty accelerating, i have a scheduled free inspection at a nissan dealership so hopefully i will figure it out, but i would greatly appreciate any help on what to expect.
I dont want the dealer to tell me that i have to replace the whole engine and ill be clueless about the situation......

i use to have a Gst eclipse, and this same problem emerged and a simple spark plug and wire and oil change fixed it up.

im new to the Z community so any help is appreciated.

thanks,

Logan

[figo_madrid04]

btw the info on the car is from the previous ride the new ride is


91" 300zx tt,
intake
ecu
custom exhust


only have had it for 3 weeks
many things to come
thanks

[k3smostwanted]

could have simply had a spark plug foul on you...always think simple first.

timing belt been changed? how many miles? if you dont know if the timing belt has been changed or it has been 60k miles, do yourself and get it changed immediately. this will cause you to buy a new engine due to unfortunate valves getting hit very hardly buy solid metal pistons.

[talonlover]

I'm a old DSM guy too and if that happened the first thing I think of is a intake leak or a boost pressure leak(ie. hose blown loose). That doesn't explain the knocking but if you do have a boost leak then you would hear a poping noise from time to time which is the engine backfiring through the intake and would sound similiar to a knock.

[figo_madrid04]

thanks guys for the help sorry for the late response just finished a hard long week or exams.....

the car is in the mechanic right now, im having a friend work on it and diagnose it , ill figure it all out soon

thanks again

[figo_madrid04]

OH MAN, Bad news, after opening up the head, i have come to learn that an intake valve in the 2nd cylinder is messed up.......... this means that im going to have to change that valve, ....
Compression is fine so i know its not the piston and such...

however i have a couple of questions,,

while having the Head open what could be a couple of upgrades that i could do that would save me time and money, anything from manifold, to the valves, head gaskets and part in the head ect..........
any parts, jobs, websites, are all good help,

any help is appreciated , however keep in mind that i want the car to be able to pass emissions....hehe...
thanks

[k3smostwanted]

Originally Posted by figo_madrid04

OH MAN, Bad news, after opening up the head, i have come to learn that an intake valve in the 2nd cylinder is messed up.......... this means that im going to have to change that valve, ....
Compression is fine so i know its not the piston and such...

however i have a couple of questions,,

while having the Head open what could be a couple of upgrades that i could do that would save me time and money, anything from manifold, to the valves, head gaskets and part in the head ect..........
any parts, jobs, websites, are all good help,

any help is appreciated , however keep in mind that i want the car to be able to pass emissions....hehe...
thanks

JWT Mild Cams!

[figo_madrid04]

any good head rebuild kits, i need to make a decision asap and i need to know what price range im looking at and exactly what components i will be replacing,

I was valves for about 500
springs about 300
retainers about 400 or soo

is it going to really cost that much or are there kits that have better deals,
btw, as of now im only looking to run the car no higher than 20 psi at any given point but right now i have a valve issue which im replacing but would prefer to do a complete head rebuild.
any help is appreciated
thanks

car is a 91 z32 tt , basic intake ecu custom exhaust upgrades
thanks again

[pnoiSR20]

Port and Polished cylinder heads might work?

[k3smostwanted]

Originally Posted by figo_madrid04

any good head rebuild kits, i need to make a decision asap and i need to know what price range im looking at and exactly what components i will be replacing,

I was valves for about 500
springs about 300
retainers about 400 or soo

is it going to really cost that much or are there kits that have better deals,
btw, as of now im only looking to run the car no higher than 20 psi at any given point but right now i have a valve issue which im replacing but would prefer to do a complete head rebuild.
any help is appreciated
thanks

car is a 91 z32 tt , basic intake ecu custom exhaust upgrades
thanks again

check out z1motorsports.com, sgpracing.com, conceptzperformance.com, and amzperformance.com

they all either work on the Z32 or sell anything and everything for them. i know Z1 motorsports sells completely rebuilt heads for $600+core.