So I'm driving on the access road and some guy jumps across lanes and cuts me off so I slam on the brakes and my car stalls out, I turn it back on put it in gear and go and about 5 mins later I'm sitting at a light and the rpms start to go up and down, up to about 1300 -1500 and then back down to normal, does anyone know what could cause this on a 94 accord f22 vtec, thank you for any info

 

Vacuum leak/hose disconnected
Fast Idle Thermal valve out of adjustment/dirty
Idle Air Control valve dirty/disconnected
Low Coolant

There is a DIY on cleaning the IAC & FIT valves as well as how to check for vacuum leaks.

 

Ok cool I'll try cleaning out the IAC and FIT valves first and hopefully that fixes it, thank you very much for the help

 

You could start with a quick check for a loose electrical connection on the IAC or loose vacuum hoses on the intake. Doesn't take much for it to surge like that.

 

Oh really? So me braking all of a sudden could still cause one of the hoses to come loose on the IAC valve? Sorry for all the questions I've just never had this happen to me before

 

I don't think he meant the hoses on the iacv might be loose, he meant the electrical connector on it may have jostled loose if it wasn't plugged in all the way. It should click shut, so just pull it out and push it back in until it clicks. If that's plugged in, check the various vacuum lines going to the intake manifold for leaks.

I believe this is a safe/effective way of finding vacuum leaks, but check with a more knowledgeable member before attempting: You can take some propane or some kind of combustible fluid like carb cleaner and spray it around the vacuum lines until you hear the rpm increase... if you can get the rpm to jump up consistently when spraying in one spot, that's the area that has a leak (it sucks in the gas/liquid which causes a jump in rpm).

If no leaks are found, make sure the coolant level is sufficient and bleed the cooling system to remove any potential air pockets. There are many DIYs on bleeding/burping the cooling system around the internet.

You may want to just remove/adjust the fitv and remove/clean the iacv before checking for vacuum leaks and bleeding the cooling system. It's a good maintenance job to do anyways, and you may have to bleed the cooling system after removing and replacing the iacv if enough coolant leaks out of the hoses when you remove them, so you may as well do those 2 valves first (after checking that the iacv is, in fact, plugged in).

I believe the above is what the previous posters were suggesting. Apologies if I misinterpreted their intent, but that's a starting point.

 

Just a thought: The vacuum line from the brake booster to the intake manifold on my accord was very loose at the booster... The original clamp didn't secure it very well. It's possible this vacuum hose slipped off or loosened when you slammed the brakes.

I recently unhooked this hose to pour seafoam into my intake manifold, and when removed it caused the idle to go crazy and jump from 1k+ rpm down to almost 0 rpm, nearly killing the engine. It sounds like that could conceivably cause your idle problem.

Look for the big round black disc on the firewall right in front of the driver (under the hood). There is a vacuum hose running from the top of that to the intake manifold. Make sure that hose is clamped securely and not leaking.

It may be an unlikely culprit, but it'd be easy to check before you tear apart the fitv/iacv. Hope this helps.