ajsuper7

hi all, its been awhile since i last posted on this forum since my 91 na had a PD failure that caused my car to die of fire. im in the process of rebuilding but i have a few questions first and for these i searched so dont tell me to search:-). i want to go turbo, but i dont see anyway that this could happen ie there are very few tII's around houston and it would be expensive finding all the parts i would need. so im kinda stuck being na. if i got a large streetport with ported manifolds would i be able to use the stock ecu and still pass emmissions? once i passed emmssions i could go to something like a safc or other computer but i have to appear to be street legal for now.

thanks

selanne8

i've got a street port on my car and i did not pass emissions with all the stuff in place.

the short version of it is, with your port job, the engine will be sucking in more air than normal. the ecu sees this and compensates by dumping in more fuel. when it does that, it runs rich and you fail.

my mechanic suggested to install an s-afc to lean out the engine (he said that's what he did with his 3rd gen to pass emissions). i did that and passed like a champ :-). course after that, i swapped back my straight through pipes instead of the cats (you will be doing that, right?)

john

DigitalSynthesis

Bummer on the car fire man...

I agree about the S-AFC... if that's more involved than you'd like for passing emissions though, there's my fail-safe rule: 2 gallons of denatured alcohol in 3-5 gallons of gas. Guaranteed to bring your exhaust to about the cleanest damn thing in the state. Just drive like a baby on the way there and back, add a few more gallons of gas after you pass, let that drain around town (again taking it easy), and fill it up again like normal. Worked like a charm for me.

Your S5 had a pulsation damper fail? I thought those things were welded into the rail (at least mine is) ... how could that fail? If you have any info on that, I'd like to know...

ajsuper7

great, thanks for the info. i didnt look at the fuel rail so i dont directly know about the s5 PD. but i have read recently that there were many PD failures among both s4's and s5's. mazda did change the design but it was not a perfect anwser. my mechanic works at a mazda shop with plenty of experience with rx7's and said he was pretty sure thats what happened.