Well ever since i got the car i started noticing some problems on the z. One of the main problems is misfiring. At idle you could hear the car misfiring lightly. What causes that? I don't know if the spark plugs have been changed lately. When i have time i'll try to get some ngks.

Another problem is the exhaust smell is really strong. My uncle says the z is running rich. When we got the car it had a k&n filter on it. It was really dirty and black in color. I thought that was the reason why my car was running so rich. So i purchased a k&n cleaning kit and tried cleaning it. After cleaning the filter it looked much better than before but it was still kind of dark in color. Should i just buy another filter? Or is there another reason why my car runs so rich. I haven't checked timing yet.

My last question is would running Seafoam help solve some of my problems? I did some searching on Seafoam at different forums and most replies were positive.
My z has 157,000 miles on the engine. The idle is not rough but changes sometimes. Usually the z runs between 1000-1100rpm. When i first start it the idle is normal then it goes to like 1300-1500rpm then it drops back down to normal. What causes this? I know there's a lot of things to check out. Vacuum lines, spark plugs, etc..

 

*bump i've got a new problem. when i rev the car to 4k blue smoke comes out. im thinking it's def. coming from the turbos. the turbos are original with 157k mi. on them. i would want a jdm motor but don't really trust the companies around here. im thinking about just getting a rebuilt from z1 and mayb sport 500s.

 

I would prolly do a compression check. That will tell you alot about the condition of things inside. If the numbers are low then it's time for a rebuild. If the numbers are o.k. then you can work on new turbos and solving your mis-fire.

 

yea i def. want to do a compression test on the z. i plan on doing it myself. i was looking around for compression tester and found some cheap ones at summit.
would these be ok to use for the compression test?
http://store.summitracing.com/defaul...=egnsearch.asp

i got all the other info from this thread:
https://www.zdriver.com/forum/showth...ht=Compression

 

Cheap...

I'm not a vet in the Z game by any means... but in my experience working on cars.... if you love what you're wroking on... "cheap" isn't usually the best answer. Go see a trusted mechanic buddy... and have him do a compression test with quality equipment and a professional touch.

174psi is perfect on a Z cylinder ... 121 is the acceptable minimum.
keep in mind as well... you dont want any more than a 14psi difference in any 2 cylinders

if any of those values get too out of whack... i'd recommend a rebuild... certainly before any turbo upgrading or boost increases.

 

then again... some people are more strict or less strict for the cylinder variation... i've read as low as 8psi difference... and as high as 15-16... I say 14 because it sounds like a good medium. You make that decision in the end.

 

Here is the actual compression SPECS

That 21.99 compression tester from summit should be o.k. I personally would go with one that measured closer than 10 psi increments. Maybe one with 5 psi increments.

 

If you're considering the JWT 500's then you should consider Z1's GT525's. Less expensive and you get all of the gaskets, oil lines, etc.

 

just checked it out and i think i'll be going with those. as long as i replace the ol' turbos. i've never felt the car go with brand new turbos. at 157k im pretty sure the stockers are worn badly. i could still feel boost but usually after 3500rpm.

 

I was in the exact same boat is you. 152k miles on the clock and I didn't suspect my turbos bad. Boy, was I wrong. I'm still waiting on my shipment from Z1. I placed my order nearly 3 weeks ago.

 

I dont know why you would want to go with a JDM motor...You would probably have more problems in the end. Those motors have been driven hard usually and the only difference between the USDM and JDM is the turbos. Get it rebuilt with better internals. I know AMZ has a good rebuild kit for the Z32 with turbos. I am sure you could work out a deal with mitch to substitute the included turbos for something more powerful if you wanted to go in that direction. But if it was my money that is what I would do. http://www.amzperformance.com/z32/?p...71713f8f0f84d&

 

The above option looks like an awesome deal! another option would be to buy a block frm SGP (apparently, according to Rizz, the customer service at SGP has been lacking lately though). You can get a nice short block for as cheap as $2700. Take a look.
http://shop.store.yahoo.com/sgpracin...300zxttna.html

 

I'm just relaying what I've heard. I've only purchased the clutch line kit from there and have had no problems. The service that most ppl are talking about i think is restricted to their local service.

There's many other differences besides the turbos. The cams specs are different as well, which is probably why a lot of ppl have rough idling problems with their jdm swaps.

 

Well Im still learning about the car so thanks. I have only heard people talk about the turbos being different. I just always hear people say that the JDMs are not worth the money like other cars and I do know you have a 50/50 chance of those things being a money pit.