B16, B18, B20
User avatar
By LaosToaster
#248540 So heres a long story, my previous problem with my b16 was the ckp sensor which is fixed now. now i have backfiring/chugging/hesitating/rough idle issues and i have to like ride the clutch when taking off to prevent stalling and chugging. i used a timing light to adjust my timing, i think my ignition timing was off by 6-10 degrees of the red mark, so around 6-10 btdc?? but anyways so i went to adjust it to specs, right on the red mark, i had moved the distributor almost all the way advanced. but when that was done, my car still ran the same. and it made these weird random hiccups, i dont kno how to explain it. i was shooting the light while it was hiccuping and it appears to affect my ignition timing like about a degree or two then goes back to the red mark. i had it running for a good 15- 20 mins to warm up, so after that i started to rev it on the throttle cable, just little revs, and it would choke and almost die and backfires. if i slowly rev it, like really slow, it doesnt back fire or anything, but if i rev a little real quick, like a tap it would choke and backfire. and then all of a sudden it backfired hard enough to stall my car.


i have no clue what the chugging means when idling though, never happened before.

anyone know what it could be?
im gonna try again tonight or so and really fuck with it.
im getting tired of getting the one problem after another problem solve..sigh

oh yea and no CEL, and another thing is i did forget to jump the connector, but i turned off the engine, jumped it and then turned it back on.

maybe im not doing the ignition adjustment right :?
Last edited by LaosToaster on Sun Apr 10, 2011 7:49 pm, edited 1 time in total.
User avatar
By That One Dude
#248764 If your spark timing is dead on, you either have a vacuum leak or your timing belt is off a tooth or two.

Since you said it bogs down when you go to give it a small amount of throttle, my guess is vacuum leak.

How does the engine idle?
User avatar
By LaosToaster
#248770 The weird thing is that my bouncing idle went away when engine is cold. My idle is a steady 1000-1200 cold. And when warm around 750rpm. I might have to redo the ignition timing even though its spot on. The idle is rough though.

My timing is spot on too, I check that before adjusting the ignition timing.

And yea when I rev a bit quick it will backfire. Like its weird though, when I rev the throttle the engine doesn't response right away, it feels delayed and the it bogs and backfires. In other words, I hit the throttle the engines feels like its gonna stall, then revs then bogs then backfires.[/url]
User avatar
By 94EJ2
#248799 sounds like it may be dumping to much fuel into the engine have you checked your fuel pressure regulator
User avatar
By LaosToaster
#248806 Well here's an update. I did my ignition timing adjustment the right way. I think I got rid of the back firing problem now, but if the engine dips too low, like below idle rpms it will backfire, haven't really tested that out to comfirm. Now another thing is that my idle is not smooth, my car used to be smooth like a purr when I feel the exhaust gasses coming out the muffler, now its in pumps kinda way, in idle,when warm or cold. But idle does get smoother as it warms up, but not smooth enough.

So basically both my timings are correct but its not idling as smooth as before. Revving in the low rpms (900-2000rpms) my engine will shake, nothing violent though, jus not smooth at all and no backfiring, but then revving above that it runs mint, nice and smooth. Oh yea and my car doesn't do these weird hiccups in idle anymore as stated in my previous post.

I haven't really thoroughly checked for vacuums I can only hear the hiss of my intake tube filter. BUT, BIG BUT, WHY ALL OF A SUDDEN MY SURGING IDLE WHEN COLD WENT AWAY?,(had this problem since I owned the car and never bothered to fix) this is very interesting to me.

And I haven't checked the fuel pressure regulator, but I don't thinks its that since I got rid of the back firing by correcting the ignition timing,the right way. The last time I adjusted I didn't do it right, I thought I did it right though so yea.

I think now I'm just stuck with a not so smooth idle issue/low rpm rev issue for now.

Thanks for the input guys :)
User avatar
By suspendedHatch
#249407 You have to jumper the connection before adjusting the timing, and then reset the ECU afterward.

Idle quality is very closely tied to ignition timing. The ECU uses ignition timing adjustments to keep the idle smooth because the engine responds much faster. It's like fine tuning the RPMs while the IACV is like using a sledge hammer.

Were the RPMs in range when you set the timing? You need a diagnostic tach plugged into the plug on the shock tower to get an accurate reading. Make sure the throttle cable has slack, then engine is at operating temp, jumper the ECU plug and then adjust the throttle screw to get it idling at spec RPM.

Advanced timing will raise the idle speed. When the engine is cold, the ECU will raise the idle speed and run rich. It ignores the O2 sensor since cold O2 sensors don't work. When the coolant warms up, the ECU will run a stoich mixture by referencing the O2 sensor, and lower the idle speed to 750. Much easier for an engine to idle smooth in higher RPM than lower.

If the idle speed goes above a certain point, somewhere around 1500 RPM, and there's no TPS input (you're not on the gas), it will cut the fuel until it drops to 1200 and that's where you get the revving idle.
User avatar
By LaosToaster
#249410 hmm very interesting. damn i did forget to reset the ecu. after being done with adjusting it i just unplugged my jumper but never took out the ecu fuse/ unbolt neg batt wire. my idle when cold is around 1500 then slowly goes to 750 when warm :)

the idle was at 750 when adjusting ignition timing.
User avatar
By LaosToaster
#249557 ok update here. im so stupid. i have no idea how my car started before, but it didnt this morning. i was looking at some random forum and it talked about the firing order, i looked at mine and my #3 and #4 spark plug wires were swtiched :x

its funny cuz now my cold surging idle is back LOL :lol: i dont care as long as my shits up and running now.

and yea my timing was good all along and i used my old distributor too, smooth idle, no backfiring, everythings back to normal now. Thanks for everyone who helped. :) :) :) :) :) :) :D :D :woot: :woot: :woot: :wink: :wink: :wink: :wink: :hehe: :hehe: :thumb: :thumb: :thumb:









:fucker: :chance: