How can I be sure ignition timing is correct if IACV is not adjusted?

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krsh_tst_dmmiez
Posts: 4
Joined: Fri May 21, 2021 7:59 am
Car: Four 240SX coupes

How can I be sure ignition timing is correct if IACV is not adjusted?

Postby krsh_tst_dmmiez » Sun May 23, 2021 2:13 pm

I searched for a similar topic but can't seem to find one with this particular "problem". I have an s13 with a 95 ka (not that it makes any difference since head and block are interchangeable, but I installed the motor in about a month ago and it doesn't have that WOT kick that I remember KAs having. It feels a lot like turbo lag at first and kinda doesn't feel as juicy as I think it should. The engine doesnt have symptoms like rough idle or hard starting and for the most part all throughout acceleration it's very smoth, but just doesn' feel strong, it's fast (based on how KAs run) but it takes a little bit to get there. It'll spit/sputter very lightly every now and then after letting off throttle but it's not that bad. Anyways my theory is maybe the IACV is messing with my ignition timing. When I first got the car running I used the timing loght but I couldn't get it on the right mark without poor throttle response. How can I "start over" with setting ignition timing and iacv setup?


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NukeKS14
Posts: 213
Joined: Wed Apr 10, 2019 2:50 pm
Car: 1995 240SX SE - KA24DE-T
2014 Camaro SS 1LE

Re: How can I be sure ignition timing is correct if IACV is not adjusted?

Postby NukeKS14 » Thu May 27, 2021 7:51 pm

S14s have milder cams than the S13s due to deletion of the butterflies in the intake manifold. Timing light is only going to be able to verify ignition timing. If you had the timing set apart you'd have to pull the timing cover off and verify timing marks on the cam gears/crank/idler to verify valve timing.

There are a lot of things to look at but the sputtering may be a fuel issue as well. Do you have a wideband or any way to check if it's running lean/rich?

As far as setting ignition timing, this is still the best resource I know of, to date.

https://www.nicoclub.com/archives/240sx ... iming.html

I use a paint marker on the OEM crank pulley to make it easier to read. that IS your timing. If you have poor throttle response at that point it's either a fueling or an air issue most likely (assuming you haven't had the motor apart) but, again, this won't rule out a valve timing issue.

What does your engine idle at, as far as RPM? Have you done a vacuum leak test? What's the back story on the engine, did you just buy a used one and swap it in or...? What are the unknown variables here basically.


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