my rb25det has a funny idle pattern!!!!!

[z-monster]

hi guys, i am brand spankin new here but i have been surfing this site for a few months now to find my answer to no avail... i drive a 1980 datsun 280zx with a rb25det installed... i baught the front clip from japan and it was a very good conditioned engine... but since i got it it has never idled the way every standard rb25det i have heard idle...

i have problems starting all the time.. it takes at least 2-3 cranks of the key and lots of throttle to fire the beast, then the rpm will rise to 1000 as it warms itself up... as soon as it gets to its happy operating temp. it will start rev jumping itself as if there was a racing cam installed. rpm jumps from 500 to 750/900 rpm.... it never shuts itself off while sitting by itself but will when i am driving...... especially when i'm taking it over 5000rpm then while clutching it the engine will just loose all speed and turn itself off. i usually restart the car by letting the clutch go so that i runs as if nothing happen but this is happeing way too often and i'm really getting pissed off about it!!!

i hop ethis is a small issue and an issue that some of yall have tackled and over came. all my hoses are new and i doubt there is any leaks. i have never opened the engine but when i got it, i looks stock standard and have had 103 000km's/64400miles on it. so there you have it... i am running a gtr intercooler, hks pod filter, and everything else it stock... oh ya a sard fuel press regulator. thats it...

hope yall will be gracious enough to share your secrets... thank yall in advance.... oh i have since cleaned my idle speed controller... helped a little, was going to check my cam angle sensor next...

[Carl H]

sounds like the tps isnt set right and the car doesnt know its supposed to idle.with the engine running and warm loosen the bolts on the tps and turn it clockwise till it drops down in engine speed and holds a consistant idle.

[z-monster]

what is the TPS??? is it the big grey sensor in fornt of the block which is bolted along side the cam gear??? "cam angle sensor?"

[kouki-gymkhana]

TPS should be right by the throttle body. If I recall, it's a big grey plug.

[eh?]

For the start problem, check that your start signal to the ecu receives power when turned to start.

[z-monster]

thanx guys for your input.. i will check on these items as soon as i get my car back from the body shop... i recently crashed it and it should be out again today or tomorrow.

[ehacker01]

whats your vacuum at idle?

[NightKids2]

My car was having that start up problem where I had to crank it a few times and give it some gas, then it will barely idle then go to normal 3 days last week. Last two days Ive started it it started right up though. Hoping its just the cold.

[Rookieca18det]

Sounds kinda like what happened to me with my CA, it was my ecu that was the culprit. Not sure why it started to go bad but I had a spare ecu lying around so I just swapped them and the problem went away.

[z-monster]

hey guys.. i have no idea as to what my vacum reading is coz i dont have a vacum meter. but i tried the TPS. turned it very slightly clockwise and it helped alot... now i think all i have to do is to turn it more liberally and it will solve my cutting off at high rpm problem... on hte other hand i still have the start up problem where i still have to pump the throttle a a good few times before it will fire up. what else can i check myself to fix this problem?? the start up is the last and only problem to my otherwise perfect and completed project and labor of love for the last 8 months!!! thanx guys