this idle is pissing me off.

[bataangpinoy]

i recently did the head gasket change/head swap on my seta powerd 325is(blew the b25). the 885 head is all stock, with new cam seals and rocker plugs. valves adjusted to .08. torqued to 25ftlbs, sequenced 90 90.

car will start, rev to about 1200, then settle to about 750 and then drop to 600, and surge from 500-700, stop surging, set at 450-500 then die.
ive checked for vac leaks, cant find any(but it feels like its either getting too little air). but for good measure i will get new tb and vc gaskets. the breather hose from the vc is new, so i dont see that as a source of a leak. im out of ideas, and im going nuts here.


when cold, the i have to keep my foot on the gas to keep it alive. if i keep my foot steady at 1000 rpm, the idle will drop, as if its getting too much fuel or air

when warm the idle is about 600-750, not surging.

so far ive changed the tps, inspected most vac lines, nothing there. it has been exceptionally humid, so i began to think distributor/rotor/ign. coil

changed the brake booster lines, nothing there.

next up are the icv and o2 sensor. the car was running fine last week.

[jlevie]

On the assumption that there are no fault codes in the DME, I'd guess on there being intake leaks given the recent work. Have a smoke test run and you'll find the leaks.

[bataangpinoy]

funny thing about the stomp test. i have the 173 dme and when i go to do the test, NOTHING happens. no blinking at all. am i doing something wrong?

[thereisnoyun]

same thinghappen to me, for the longest time.

clean your throttle butterfly real good. There should be a gap, you should be able to see light from the side of it. Thats what solve my idle issue.

[bataangpinoy]

hmm. mine is dirty as fuck

[bataangpinoy]

is the rubber grommet on the brake booster where the vac line goes replaceable? i think that mine is shit because when i give it gas, i hear a slight sshshsh coming from that area at random times throughout the rpm range.

[jlevie]

funny thing about the stomp test. i have the 173 dme and when i go to do the test, NOTHING happens. no blinking at all. am i doing something wrong?

That can be a sign of either the idle or WOT switch in the TPS is not working or that the TPS and/or idle stop and/or accelerator stop is mis-adjusted.

[bataangpinoy]

accelerator stop is in its oem position, the only thing ive changed is the tps, the one this unit replaced was very oily and barely clicked at all. this one is clean, and clicks.

is it possible for the plug on the harness to be bad? i cleaned it with some degreaser(the thing was caked with oil). maybe some got into the plug?

i did try the icv, it is in working order. BUT my tps may be shit as the car runs the same whether or not the unit is plugged in or not. is there a relay or fuse for the tps?

[jlevie]

A part of replacing the TPS is adjusting it so that the idle switch closes when the throttle is .020-.060" off the throttle stop. While that should result in the WOT switch closing just before the throttle plate reaches 90 deg to the throttle body, the cable can stretch or parts can wear requiring adjustment of the accelerator stop under the pedal to reach WOT.

Note that the switches need to be checked electrically rather than by hearing the click.

[bataangpinoy]

hmm. i'll have to try and re-adjust the tps then, i was not aware that they have clearance specifications. that would explain why the stomp test dont work. the switch is not reaching WOT

[jlevie]

For the stomp test to work the DME has to see the idle and WOT switch alternate five times. So both have to operate.