[baseballZ]

Hi all...1978 280Z problem (again) I've been getting it back in shape after a long nap.I changed a (leaking) water pump but while working on this problem another one has popped up.For the first time I opened it up on the highway and it cut out!! I mean it runs fine up to 60-65 but when I pressed the accelerator to the floor it just seriously cut out. Some of the things I've done in the last couple of weeks are: dropped and cleaned out gas tank(Really stopped up ) new pressure regulator,new filters (oil,gas,air)plug wires,plugs,pcv valve ,dist. cap and rotor,and water temp sensor. ( some other little things but not impt. here) So anyway,any suggestions. It seems to be peppy enough just regular driving,no misses (oh yeah...once in awhile it will burp a flame out tailpipe...you know ,when you rev it up to about 4000 rpm's while parked) I drive it around just fine...but when I floor it it seems like it won't go over 3000 rpm's. What do ya'll think.
Thanks
Frankie

 

[79-280-ZX]

Have you checked the Throttle Position Sensor, specifically the WOT contacts?

Wayne Monteath
Masham, Quebec.

 

[baseballZ]

Could you explain "checked" on the wide open throttle. I sprayed some electrical connection cleaner in there the other day (I washed the engine to change water pump and thought I might have wet it) What would I check or adjust. The contact is touching the inside one and when you depress the accelerator linkage it comes off the first one and then touches the second one. Is that it? Thanks for your time

 

[baseballZ]

ps -I gassed it up this morn and it is getting 16.7mpg. This seems about right,eh?Especially since I've been doing a LOT of idling (checking out things)

 

[79-280-ZX]

Yes, that is it...

The adjustment / test procedure is in the FSM.

Heck, this one is even in the Haynes manual.

Someone posted a link to a picture that describes this, very well, not long ago, but I'll be danged if I can find it today.

Since you were working on the water pump check all the connections to the sensors in the thermostat housing also.

Wayne Mnoteath

 

[johnb510]

At idle, the right tab should be touching the center tab. When you barely touch the throttle, the right and center contact should break. Keep pressing the throttle, still none of the tabs should be touching until you get to 34 degrees of throttle action (about 3/4 of full throttle). Then the center contact should touch the left tab. If you are getting contact one the center to the left very soon after the right and center tabs... that is bad. You will need to bend the left tab so it makes contact with the center one later.

 

[baseballZ]

Ok ...I'll check this out ASAP,but can ya'll tell me (in the interest of knowledge) what these little contacts are DOING ?!?!

 

[johnb510]

This is from the FSM:
"The throttle valve switch is attached to the throttle chamber and actuates in response to accelerator pedal movement. This switch has two sets of contact points. One set monitors the idle position and the other set monitors full throttle position.
The idle contacts close when the throttle valve is positioned at idle and open when it is at any other position.
The full throttle contacts close only when the throttle valve is positioned at full throttle (or more than 34 degree opening on the throttle valve). The contacts are open while the throttle valve is at any other position.
The ilde switch compensates for enrichment during idle and after idle, sends fuel cut signal. The full throttle switch compensates for enrichment in full throttle."