I have a 88 HB with DOHC ZC W/ZC ECU. It runs fine at idle and highway speed but is rich. No check engine lights. Checked TPS (0.45 VDC at Idle) Any ideas??


Modified by tpr at 11:56 AM 3/23/2005

 

i had teh same problem change out to a new cat. i know it will help a little

 

Do you have the test numbers? That will help us pinpoint what is causing it to fail emissions.

 

I will not have those numbers till Friday. The guy just "passed" my car so I could continue to drive. But i did not get the numbers. What are some common causes of a too rich condition.

 

most common on DOHC ZC - too much fuel pressure

 

Too much fuel pressure is the likely one but like I said the numbers will tell the story.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tpr &raquo;</TD></TR><TR><TD CLASS="quote">I will not have those numbers till Friday. The guy just "passed" my car so I could continue to drive. But i did not get the numbers. What are some common causes of a too rich condition.</TD></TR></TABLE>

Your fuel maybe not be combusting fully, might want to try a regular tune up, plugs, wires, cap, rotor, 02 sensors.

 

New plugs, rotor, cap, wires and Cat. If it were the 02 sensor shouldn't it throw a code?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tpr &raquo;</TD></TR><TR><TD CLASS="quote">New plugs, rotor, cap, wires and Cat. If it were the 02 sensor shouldn't it throw a code?

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Not always, I mean it could be acting lazy ( thats what its called ) but the reading still might be with in spec.

 

wideband and turbo edit are you friend find a tuner in your area...

Josh

 

check your o2 sensor before and your manifold is maybe broken before the o2 sensor

 

make sure your injectors are clicking...if they arent clicking they are stuck open jsut had the problem

 

Fuel pressure 30 PSI at idle, momentarily to 35-40 when the throttle is opened quickly.