mattsnooz

If you had a massive intake manifold leak around the gasket would it cause stalling?
also, would colder temperatures cause the stalling to be more frequent.

I'm having stalling issues after the car has been sitting even for only less than a day. It will crank, fire right up, idle properly for about 2-3 seconds, than attempt to die. I can give it gas and save it most times but some times It just dies. It seams like the Tach fluctuates a touch too before dying. The engines RPM's don't really change, but the tach shows that its changing. Car runs perfect aside from that, and no stored cels either. I'm sort of baffled. I'm thinking spark because even If I give it gas it still wants to die. So that makes me think lack of spark. Any input anybody anything? I have a list of things that I'm checking off that could and couldn't be the culprit. I'll post if anybody thinks it will help narrow the problem down.

Any thoughts would be greatly appreciated. Me and my buddy Allan and Todd are going to pull off the intake manifold to resurface the surfaces, put a new gasket, and gasket seal it so also any tips for removing the Intake Manifold (93 si prelude 4ws) would also be appreciated.

thanks in advance h-t members

djbrandonr

i dont think so. Usually a vaccum leak of some kinda results in higher rpm..when I put on my lovefab gasket I didnt get all the IM bolts tight enough the first time through and upon start up the car when sraight from a fire up to 9k. After re-retightening all was fine. I dont think its a vac leak.

98vtec

an engine needs vacuum to stay running. Vacuum keeps the engine from falling on its face and stalling.

yes, it will stall if you have a big enough leak that it cant recover itself do to lack of vacuum.

bluedlude

do you have an intake manifold leak?

if you are only guessing you do, i would check the FITV and the IACV first. they control the amount of incoming air and its temp at startup. so if your car is sitting and cools down itll start up and die. its like keeping the choke open to get something started. know what i mean?

mattsnooz

Yes It was a guess from a friend of mine who was a mechanic but now is working with me as an electrician. He worked at a dealership on Toyota's so he has some knowledge and suggested that being a possibility.

IF the IACV was failing it would generate a cel?! I have no cels except 62 under 4ws system lol. what else is new! every god damn 4ws code 62 lol. Should be a recall for *** sakes.

I've cleaned the IACV and it operates fine. Could be a leak there but I doubt it. I'll check. FITV how ever could be a problem? How does the fast idle thermal valve work. When its a cold start it allows more air in to keep the motor running at higher rpm to bring it up to operating temperature correct?

So I should just search how to test the FITV and look for leaks perhaps?

I'm sure this is a dumb question too though but could I do a compression test on my intake manifold? Fill it with pressure using a compresser with a pressure guage? If there was a manifold leak it wouldn't hold and would leak out and perhaps I could hear where it was comming from??? Is this even remotely possible? I half baked and just brain storming how I could diagnose this B.S.
thanks again in advance


Modified by mattsnooz at 5:09 PM 10/19/2007

bluedlude

someone correct me if im wrong, but the FITV just acts like the choke until the intake charge is warm enough. i wanna say the IAT sensor sends the ECU info and the IACV raises or lowers the RPM of the engine at idle until it is at temp at which point the IACV is fully shut.

unhook the IACV and hold it. have someone turn your car to the on position and see if the pintle moves. if it does, guess what, it works. then you check the FITV. if its still doing it, look into your fuel situation, but i really doubt its got anything to do with fuel. I wouldnt waste the time testing an intake manifold. they are like $25 on ebay all day long if you really want one.


Modified by bluedlude at 5:17 AM 10/20/2007

bluedlude

to check the FITV, the helmes says to start the car and hold the RPMs at 3000 until the radiator fan comes on. and you have to do this with the intake removed BTW. once the fan has come on, cover the lower port in the TB(the hole on the bottom) with your finger. It says if the valve is leaking, the idle speed will drop.

i troubleshooted it in the helmes, you can too. chapter 11, pages 100, 102, 114. if its not the FITV you are going to have some fun.

mgags7

^^good info Jacob

The FITV is somewhat like a reverse-choke.

There is a thermostat inside that starts open when the car is cold, and allows air from that hole in front of the throttle plate into the IM a set amount, which is adjusted by the white "screw" on the back of the FITV.

As the car warms up, the valve gradually closes, and brings the idle down.

The IACV also aids in cold start, but it simply does not have the capacity to make it idle as high as the FITV can, in conjunction, they can let enough air in for a 3000rpm cold start idle, which is how I set mine in the winter. Warms up good and quick

mattsnooz

thanks for the info men. My car's cold start ilde is only between 1300 and 1600 rpm. I would love to raise it. So all I need to do is screw in that white screw in the FITV?

LudeBehavi0r

You would want to unscrew it some to raise the idle.

mattsnooz

Where is the white "screw" anyway? my FITV is under my throttle body so would have to remove my intake piping and pull off the FITV in order to unscrew the white "screw"? Do I have to remove the cap on the end of the FITV to get at the "screw" aswell? The manual doesn't have any info on this white adjustment "screw"

thanks for your help

mattsnooz

I installed an aftermarket fpr and the stalling stopped.

I looked in the Honda Factory service manual and it said number one cause to stalling upon warm up and it listed fpr lol.

So I guess the stock fpr was worn and the valve would open too easily allow more fuel to return to the tank and less to the fuel rail/injectors??

M2B4

the white screw is inside fitv. i unbolted and unhooked fitv. took off the cap at end then just screwed white screw back in was kinda annoying cuz i only had a small flat tip screw driver with me.

edit: i think they are talking about a different white screw lol