Beretta.net

hey all
i have a 91 gtz, with an 89 quad 4 in it. i've gone for 5 e-tests now and i still can't pass it. i've replaced the cat, o2 sensor, map sensor, iac sensor, put all new vacume lines on and who knows what else. it was recently rebuilt, and has about 550 kms on it. ive tried methyl hydrate in the gas tank, and several other fuel additives.
it passes on everything, except for the HC's, at the 40 km/h test. everything else passes fine. at an idle it has no problems with the HC's.
from what i understand if HC's arent passing, it usually means its running rich. the scanner however shows that its running with a ratio of 14.6 to 1, unless you step on it, where it drops to about 12.5ish to 1, which is normal i beleive. but they accelerate slowly anyways so that shouldn't be an issue.
anybody got any ideas where else i should look. the timing is where its supposed to be also, so that isn't a problem either.
thanks for your help
scott

What ECM are you using???  COuld be the wrong memcal unit in there.

(docrodg @ Oct. 12 2006,06:03)QUOTEWhat ECM are you using???  COuld be the wrong memcal unit in there.
I agree, since an 89 would not be an HO motor, and obviously the 91 GTZ would have been equipped with the HO.

why couldnt i have thought of that. makes sense to me... computer thinks it high output... sending more fuel than is actually needed. i did a bit of research and looking around. i found that both 89 low and high output and the 91 HO have the same computer... just the prom is different. i also found a computer for an 89 so ill put that in and see what happens. hopefully that works. and hey at least i got a HO computer for when i can afford to upgrade to the HO engine
thanks for your help... ill let you know what happens.
scott

ok so i went for another e test yesterday, and the car still failed. HC's at 40 km are still the problem. here are my numbers from this past time.

curb idle
             Limit   Reading
HC ppm   200      80
CO %         1       0.03

40 km/h

HC ppm   64      103
CO%       0.35    0.29
NO ppm   727      62

apparently the new ECM  didnt help b/c these are right around the Numbers im usualy getting.  i do have a high flow cat on it though, and am running 2 1/4 inch exhaust  from the exhaust manifold. could that be a problem perhaps?. im thinking about putting another cat behind the one i got on here already. is that illegal, or will it even help?
thanks
scott

Check that your temp sensors are working.  expectily the one running to the ECM.  if its bad it can ritchen the fuel trims up if it reading cold.  also check the o2 sensor.

No I dont think duel cat are illegal. some trucks have two, ford did it for a while on rangers an broncos..

Mr Goodwrench