Slight miss at idle/ sputtering until in boost.

[beansblacktsi]

First off I have searched for this with no luck. The car I am working on is a 92 gsx. I have been driving it around for the past month and I have had zero problems until driving it yesterday.
The car fires right up and runs and idles great. The problem I am having is that at idle there is a slight miss, or little pop every few seconds. The other thing that it is doing is while driving in any gear, the car sputters from 1k on up and with a great load the worse it gets(Higher gears lower rpm). But as soon as I go wide open throttle it or get into boost the problem goes away and it pulls just like it used to with zero hesitation.
I have been through all of the basics and have replaced or switched to known good components. The car has ngkbpr6es gapped to .028, new spark plug wires, good coil pack, transistor, maf, ecu, zero boost leaks, tps set correctly and I think thats it so far. Car is stock besides an o2 dump. I was going to try to get a timing light tomorrow to check timing but I don't know how it could of changed. I was also thinking of checking fuel pressure.
Does anybody else might know what the problem could be?
Thanks, Adam

Pretty sure I figured it out, fuel filter was very dirty.

 

[viprez586]

Check timing. 5*BTDC and ground the connector on the firewall when setting/adjusting/inspecting.

My car ran like crap in boost/wot @ 5*BTDC, turned it up to 10* and it ran like a champ! Only side effect was popping and sputtering at idle every so often, and when I decelerated from high rpm It'd backfire.

Let us know how it goes.
Perhaps some log advice would help.


Just saw your update. Does it still do it? I'd still check out base timing.

 

[beansblacktsi]

Check timing. 5*BTDC and ground the connector on the firewall when setting/adjusting/inspecting.

My car ran like crap in boost/wot @ 5*BTDC, turned it up to 10* and it ran like a champ! Only side effect was popping and sputtering at idle every so often, and when I decelerated from high rpm It'd backfire.

Let us know how it goes.
Perhaps some log advice would help.


Just saw your update. Does it still do it? I'd still check out base timing.

New fuel filter and its still doing it. So right now I have a buddy with a timing light coming over now so we will check it out. I just don't understand why or how it could change while driving it because its never had this problem before.