start up issue...and then some :(

[x3rikaa]

okayy so i heard that when the engine is cold and you start it up, it should warm itself up right? as in the RPM's should be at 1200 or so?? but when i start mine up, it goes straight to 700? i have no idea where to start to figure out what is the problem but could that be from a vacuum leak? i say vacuum leak because when i hold the RPM's at 2000, it SLOWLY goes down. and at every stop light my idle changes. 1st stop light-1200 2nd stop light-750 3rd stop light-1500 and so on... does that sound like a vacuum leak? oh AND when i drive, my temp gauge goes from normal->VERY HOT->normal->VERY HOT in maybe 5 minitue intervals? can someone help me out, i was just starting to like my 240sx

[liquid_cool]

there are many possibilitys...one is a vacume leak issue and the other is a grounding issue..both are easy to fix as far as replacing hoses and adding good grounds..if the issue persist's from there..it could be a number of things..first thou..know your beast!..test test test...to test for a vacume leak..buy a can of starting fluid..make shure your engine and bay is clean..spray 1 hose at a time ..if the engine idle jumps up..theres a leak there..remove and replace..thats allso a good way to check and see if that pesky intake gasket is leakin....as for the grounding...well thats just a good idea anyways..will smooth out some idle issues with a better ground..good luck and let us know what ya find.

[x3rikaa]

hmm never thought about a ground, i guess ill check that too! thanks but heres an update:

there was a small leak from my upper radiator hose not being connected good so i gotta tighten that up (dont have tools) so hopefully my tempreature problem will be fixed

and for my idle, my fren said it could be a number of things, and one thing he noticed was the fuel pressure regulator wasnt even connected! he said there wasnt a hose there. i gotta go pick one up tomorrow but can anyone confirm that that could be the culprit of my weird idle? hmmm im starting to like my 240 again...

[carkook]

Well if the fpr wasnt hooked up to vacuum, it was giving the fuel rail full pressure all the time. That could play a role in your idle isue but I would also take a look at your coolant temp sensor. If it isnt hooked up all the way it will give the ecu weird readings, telling it needs to raise the idle to warm it up when it is already warm, or maybe like you said thinking its warmed up so it drops the idle down to 700. Just push on it and make sure its clipped down all the way.

[x3rikaa]

Well if the fpr wasnt hooked up to vacuum, it was giving the fuel rail full pressure all the time. That could play a role in your idle isue but I would also take a look at your coolant temp sensor. If it isnt hooked up all the way it will give the ecu weird readings, telling it needs to raise the idle to warm it up when it is already warm, or maybe like you said thinking its warmed up so it drops the idle down to 700. Just push on it and make sure its clipped down all the way.

oo thank you sir :]