Hey everyone, so i have a b16 del sol with a p30 ecu, i/h/e the basics nothing crazy. My problem is that it runs rough like 90% of the time then it has its moments where it runs as it should and it drives me nuts ive done alot and seemingly not narrowed it down..for example it has an intermittent low idle at stops(looks like 0 rpm on the tach) the engine shakes an when i tap the gas it somtimes jumps and idles as it should or drops back down. It also sounds like garbage (extra loud exhaust) when its running bad and is extremly gutless (no b16 jokes please, lol) as if the timing is retarding itself...ive replaces all the following. Cap,rotor,coil,icm,dizzy,map,tps(calibrated), sensors(from old d series diz), fuel filter,fuel pump,cat,plugs, wires and timing belt (timing is spot on).The problem also exists without o2 plugged in. It used to run great but has run like junk since developing this problem, It has no check engine light either so theres no help there.i noticed that when i roll my windows up rpm would raise when its doing its low rpm thing but im not sure what to take from that. Pretty much im stuck...im thinking maybe valve lash, im not sure what else to do from there so...any input helps so thanks for any you can give!

 

My del sol vtec idled like that too. All i did was adjusted the idle to 850

 

And so it gets weirder, today I rolled my windows all the way down and noticed it effected my idle so I held the switches down and my idle jumped to 800~rpm and stayed there until I let off the window switches, interesting right.....

 

check your engine grounds. and batter grounds. look for corrosion or loose grounds.

 

As stated above, definitely sounds like a electrical issue.

Check grounds, connections and alternator

 

sounds like an electrical issue. check and clean all grounds.

 

k I am going to say something completely original sounds like an electrical issue. Maybe you should Check grounds, connections and alternator

 

Mine does the same lol I know myvalves gotta get adjusted and my new lmas put in as well but yeah check all your grounds n stuff first good luck bro

 

Check all 3 grounds (valve cover to radiator support, trans to frame, and tstat housing) and battery connections making sure they aren't corroded also have alternator checked and clean your throttle body I'm about 99% sure its a ground or something simple

 

So I've got an update, turns out my exhaust cam was off a tooth and the idle problem still exists but if I let my car warm up before I drive it I doesn't happen at all otherwise its same old irratic idle, weird right.

 

Does the CEL work?

Have you adjusted the ignition timing to spec with a timing gun?

Have you cleaned the IACV?

 

Yea the cel works, I've checked by pulling sensors and getting it to pop on. I also checled timing with a gun and its spot on and I cleaned the iacv even tried a new one and still nothing. The mystery contiues it seems that anyone with this problem never fixes it or at least never posts what the problem was so I'm going to make sure and post it when I fix it.

 

Problem 100% fixed, the throttle body gasket had carbon build up that plugged up the idle screw. Replace gasket and clean TB and it idles like money.

 

Thanks so much for posting your solution. Im having the same problem with my 00 gsr
and like you said there are 100 posts about this problem but no one ever updates their post.
Going to pick up a new tb gasket today and see what happens.

 

very nice

 

Is the check engine light is on? I'm assuming it is.. i would start from there hope that help

 

Glad you found a solution.

No doubt. Just looking at all of the idle problem posts, you'd think like half of Honda's didn't idle right!

Not bad advice, but you're a bit late.

 

It sounds like a IACV problem (atleast the idling problems). I have issues like this sometimes on my car (but this is to be expected as I have no IACV). You should def take ur IACV off and clean it. Also check for disconnected sensors.