Domoisback

not sure if this is the appropriate section for something like this but anyways,

i have a turbo d16z6 and just yesterday i noticed something unusual about the car when it idles.

For some time now I've had a lopey idle due to maybe a bad IACV...(im not cammed). Ive cleaned out my IACV in the past, which if i remember correctly fixed the issue for a good 3 days. I didnt bother replacing it since its quite expensive to get a new one and since i didnt think it was that much of a big deal..

Just yesterday i went to start the car and although it still idles completely normal on cold starts and drives completely fine, i can now hear a lot of popping on warm idle, especially when letting off the gas from 1500-2000rpm when coasting in neutral.. One thing i have observed is that when the lopey idle and/or popping occurs, my air/fuel ratio dial goes all the way to lean or just doesn't read anything at all...as opposed to reading 13-14 as it used to on normal idle...

I dont know if this has anything to do with it but this issue first appeared after i had fixed a leak from my fuel rail (which could have caused the boost cut i mentioned in a previous post). I put everything back on properly and my fuel pressure is still at a steady 60psi

motoxxxman

check the valve lash adjustment. you'd be surprised how much of an impact that can have if it's not within spec. if all is well there, do a compression test. If all is well up to this point, I'd say it's either an issue with the tune, or you have some terrible gas in the tank

Domoisback

I actually did a compression test just a few weeks ago to make sure everything was fine and all seems to be in good health, 150 across the board (im also running a lower compression ratio). Ill check the valve lash but im sure its still in spec.

As for the last reason, i wouldn't be surprised. Ive had many people i know tell me the same thing.. Who knows

Domoisback

Ok so i just went through a misfire diagnostic when i was changing the sparkplugs...

I unplugged each plug on by one and the only one that didn't change the lopey idle was cylinder 1. However i can see a spark when i pull the plug out...

I also unplugged the wire while i had the car idle a bit higher and it changed how the engine ran entirely...making literally sound like a lawnmower.

It seems like it isn't firing on idle but yet is when the car is under load or anything above idle...

anyone ever heard of an issue like this?

DumpdEJ6

For me, misfires are almost always more apparent at idle than at higher RPMs. I think it is because when each cylinder is firing slowly it's more obvious when it's not firing, whereas when it's rotating faster the misfire gets "lost" in the speed of rotation. I just woke up so I hope that makes sense, lol. You probably have a minor misfire, not something that makes it misfire every single rotation but one out of every 2-3 rotations. I would do a tune-up and see if that helps.

Domoisback

would that mean that i may have possibly skipped a tooth in my timing belt? and yes that makes complete sense LOL

m4xwellmurd3r

how do you plugs look? how old are your plug wires and ignition components? It could be the result of worn out parts.

I had old plug wires that were causing some random misfire issues and a weak spark on cylinder 1.

Domoisback

well the wires i haven't checked but i rebuilt the distributor just last summer. All 4 wires are giving a spark its just that cylinder 1's wire seems to just give a spark every 2 rotations as mentioned before.. That or its just too weak to spark every time.

Ill see how much they are at my local parts store

NoobMechanic

try pulling the plugs and resetting them