Hey everyone, I'm having some difficulties with my idling. I had clean my idle control, then put back in, about a 10 min drive car begins to lose power. At one point car turned off, got it back on but as soon as I tried to give it some gas it cut off again. This happen about 3 times and then I had to get the rpms higher so it can run. I looked for vacuum leaks none I saw one of my ported vacuum switches was out so I replaced it, but still dose the same. I don't know what it can be. Please help!! thank you

 

As always go back and thoroughly check what you just worked on and the surrounding area. From your description i am ssuming this just started happening after you worked on the car.

It is difficult to "look" for vacuum leaks if that's what you suspect. Some people spray carb cleaner but I use an unlit propane torch with the tip cut off and a length of hose on the end to route the propane to different points around the intake and other parts where leaks are suspected. Do this at idle and see if the carb cleaner or whatever you use changes the idle. If so it will be being pulled into the engine at the leak point which changes the idle speed.

 

And make sure the alternator is charging the system properly and dropping down too much which will cause the ECU to cut out. On a cold start the alternator output should be 14.4 volts and as the engine heats up it would drop a little but still stay around 14 volts or so. The voltmeter gauge (if you have one) does not necessarily reflect an accurate reading. The output cable of the alternator is the best place to measure.

 

Listing your CAR SERIES may help this thread too.

 

Okay thank you for the ideas I can check out now more of an idea area and its an s5 I think? 1990 gtu

 

And check for error codes. You have a green check connector near the lead coil w/only one wire which is colored orange. Ground this wire to the negative battery terminal, and w/key to on, any error codes should be displayed.

 

Also about finding vacuum leaks, since most of the time they're a pita to find, I would just replace all of the vacuum hoses according to the ones on the vacuum routing diagram on the FSM. Saves the headache of trying to find it manually... well unless you break a nipple off a one-way check valve or one of the solenoid valves. Lol

Were you able to also check and adjust your TPS and ISC? Those might help with your idling issue.

 

Thank you for all your help guys!! It was one of my throttle nody sensors with my mass air flow sensor

 

This works well but I have never scrutinized it from a safety standpoint if something was to ignite the gas. Also, I have heard that propane is heavy and can settle in areas.

I know the use of propane for vac leak checking is talked about in other car forums but not necessarily via hacking off the end of a torch. It could be advisable to use a different setup. I don't have much experience with this kind of stuff so I just don't know.

Something made me think again of this recently and I realized I had posted about it several times.