[Garrett_76_280z]

Hey all,
My car has been running slightly rich for some time now. It wasw much worse but I have replaced both the AFM and the water temp sensor. THere is really just hesitation throughout the midrange of the throttle, wide open it is fine. Is there another sensor that could be bad?Please let me know what might be causing this

Thanks so much,
Garrett

 

[vegacharger]

from what I have learned in my 78 (which had the same problem) I had hesitation on acceleration, which was the vacume advance, and it was also running really rich until about 2300 rpm....it turned out to be the throttle position switch...located on the side of the intake. It has 2 switches in it...one for idle, and one for WOT (wide open throttle). Mine was always on WOT and hence ran to rich at idle...here is a link to a pic of the inside of the switch with some info on it.
chris
http://photos.yahoo.com/bc/vegacharger/vwp?.dir=/Yahoo!+Photo+Album/280Z&.src=ph&.dnm=throttle+pic.jpg&.view=t&.done=http%3a//photos.yahoo.com/bc/vegacharger/lst%3f%26.dir=/Yahoo!%2bPhoto%2bAlbum/280Z%26.src=ph%26.view=t

 

[johnb510]

EGR can be plugged up. Remove from manifold and clean.
Check the vac advance on distribuitor
Test the thermotime and coldstart valve
Injectors could be hanging open
Bad coil
Bad wiring in ECU harness (clean all connectors, replace in needed... see my post earlier for a guy named Nathan. Will have the info you need)
Leaking fuel lines? Check around the fuel pump, in the engine bay, ect. Only replace with fuel injection hose!
Do you have a factory service manual? If not, get one!

 

[Garrett_76_280z]

Thanks, so then once I have the cover off, how should I inspect it to see if it is broken. Then is there any way to correct it if its in wot all the time?

 

[vegacharger]

With mine, the WOT switch was touching the middle contact at all postions.....I had 2 others from the junkyard that did the same thing, so it took me a while to figure out what the heck was wrong. I just bent the WOT tang out a little so that it only touched when it was supposed to. I took the switch off the car before I did this....two screws and a plug....that's about it. basically, when it's in idle, the middle should touch one contact, between about 4 and 30 degrees, it shouldn't touch either one, then it touches the WOT...it's pretty obvious where the contacts shoud take place...use an ohm meter between the middle and the other two contacts on the plug....good luck and I hope is's something this easy..easy to check at least.
chris