hesitatation

[clickdoc]

hey guys -- i need your brains

have a question for you ?

i recently had hesitation probs in my z -- 1990 na 300zx -- after going through the long list of possibilities -- had the o2 sensors replaced -- fixed ! done deal -- now i live in Chicago and of course it is as cold as a well diggers butt -- and after the last recent cold snap i started having hesitation problems again -- i had also let the gas tank get well below 1/4 tank -- supposedly a no-no due to possible condensation problems in the gas tank -- i have used heet and it hasn't seem to work yet -- is there a better solution -- everything that can cause hesitation has been fixed or replaced -- does the H2O in the tank sound plausible ?? it was a real beast trying to get the hesitation fixed the first time -- can you use too much heet ?? at what point should you add it -- when the gas tank is nearly empty ?? does it matter ??

thanks for all your help

[nsrZ32]

Sorry I didn't get back to your e-mail man.

I wouldn't use too much of that heet stuff. As for the hesitation, it could be any of a ton of things but most likely a fuel related issue. Does it make any difference if you park it in a heated garage over night and then start it up?

[freakonaleash1187]

Also, take a quick check of your spark plugs if you haven't already. A foul plug or two can cause problems.

[clickdoc]

i only wish i had a heated garage -- no it all started after a really really cold time here in chicago -- after many months of no hesitation -- plugs are all new -- injectors are new -- no evidence of obvious vacuum leak -- the entire list of hesitation probs has already been addressed -- mostly new parts for them -- any cold weather Z owners out there ??

thanks

[zvinner]

I just finished putting rebuilt head on my '90 na, and once i got it running it kept missing. i went thru a whole slough of possible problems, and finally changing the ignition module and cleaning the air filter was what made it run. also- does it hesitate after it has warmed up? If you can't figure it out, there are a whole bunch of diagnostic procedures laid out in the service manual engine fuel/control section. good luck...

[freakonaleash1187]

Have you ran an ECU diagnosis yet? If not, do it.