98 zx2 manual trans, getting 25mpg - is that normal?

[AltecZX2]

s/r pcm's dont have the ability to tell an auto trans when to shift

[bjboertje]

so, whats a good pcm for an auto? the ngpo? or is it only for manuals too?

[Markb873]

I was geting about 25 mpg then when I changed the timing belt, I noticed the timing was way off. I assume it's from the factory because i bought the car new and it never had timing work. Anyways when I corrected it I went up to about 37 at a 50/50 mix of highway/city and the engine ran much smoother. I have a feeling that more than a few of these cars were carelessly assembled at the factory. Either that or that friction bolt on the intake sprocket slips out of wack every 100,000 miles or so but I have never got over 25 until recently.

[darktsx]

Originally Posted by Markb873

I was geting about 25 mpg then when I changed the timing belt, I noticed the timing was way off. I assume it's from the factory because i bought the car new and it never had timing work. Anyways when I corrected it I went up to about 37 at a 50/50 mix of highway/city and the engine ran much smoother. I have a feeling that more than a few of these cars were carelessly assembled at the factory. Either that or that friction bolt on the intake sprocket slips out of wack every 100,000 miles or so but I have never got over 25 until recently.

So, wait .. you just replaced your timing belt and the efficiency went up? Do you know what the specific timing problem was?

[Markb873]

I am assuming that stupid intake sproket was slipping. I lined up one cam, turned the other cam to make it line up. took off the belt. and gave the crank a good turn before it hit the timing peg. Reguardless the intake cam was not lined up with the crank. I never know where I'm at with that exhaust cam I just take it off take out the VCT and start from scratch, just line up that single hole at 12 oclock and hope that it still lines up once you reconnect it and rotate the engine a few times. I only had to do it 3 times before I was happy. Plus it was 95 outside. I was in a pissy mood.

[AltecZX2]

Originally Posted by bjboertje

so, whats a good pcm for an auto? the ngpo? or is it only for manuals too?

the good Auto PCM's are EMA0 and JZB1....you can find them on ebay, they let the auto tranny rev out a little farther.

[AltecZX2]

Originally Posted by zx2guy

was there any one upgrade that gave you the most noticable increase? and did you ever get that intake manifold work done?

Going from XHG3 to NGP0 the car felt much better due to the added timing, the pully made the car feel like it was more rev happy, and pullig the knock sensor made the car just feel VERY smooth in the powerband(ad is according to my dyno)


Im working on a SVT mani swap.

[jldude]

Originally Posted by AltecZX2

i get 25 around town....42hw

I get 36/42 city/hwy as well, all I have is Zmax treatment, knockoff brand tornado fuel saver, and bosche platinum4 plugs. And a manual trans. of course.

[jldude]

Originally Posted by AltecZX2

i get 25 around town....42hw

Imagine if these cars had a wide ratio six speed like they need to cruise around at 2KRPM@60. I guarantee they could get 45 or more mpg.

[Markb873]

Here jldude here's a Christmas Present for you!

https://www.zxtuner.com/displayProdu...&categoryId=17