Can a bad MAF sensor cause a no-idle problem? The car starts right up, but dies immediately unless I save it with the throttle. I am suspecting the IAC, but wondered if the MAF could cause this too, especially since I'm getting code 34.

 

unplug the MAF relay or the MAF itself, and try again.. if it has the same symptoms, then that's not it.. does sound like the IAC could be the culprit

 

I unplugged the MAF, and the car seemed to run even worse! So I guess that leaves me with an IAC problem. Thats good cause I would rather spend $40 for an IAC motor than $150+ for a used MAF!

 

As far as I know, the IAC might not necessarily be bad, the passage that the air comes through could just be clogged with carbon, not allowing the air that's need, to come through.. do a search and you can see what other people have said about cleaning the IAC passages, and such.. I think there's even an article on the front page of TGO, but i'm not positive

--- Just checked, and the article is on adjusting the IAC, not cleaning the passage


If anyone else has an opinions on what could be his problem, please post, as I'm no expert

 

My car did the same thing. When I unplugged the MAF, it sounded different, but not really better or worse.

...it ended up being the MAF. I'm no expert, just reporting what happened.

 

The car should still start up and idle with a bad MAF .
Because the motor isnt under a load.

One way I have tested MAF sensors with out any tools except a screw driver... Is to get the car to idle what ever it takes to get it to stabilize and then knock on the sensor with a screw driver if it simultaineously fumbles then its the MAF.

But I think its something else. Have you checked your fuel pressure?

 

yeah, I just replaced my fuel pressure regulator yesterday as a matter of fact. It was dumping gas out of the vacuum line into my plenum!! So now the car starts great, but won't idle. The pressure is 45psi at idle, 55psi at WOT. I thought that seemed a little high. (Isn't stock about 38psi?) Its an adjustable regulator, but I already have the adjusting screw all the way out. Do you think that is far enough off to drown out the motor?

 

The last few days I ran with my MAF disconnected because I forgot to reconnect it after removing my air conditioning. My car was running like crap, wanting to fumble and it would usually stall unless I gave it gas to save it. I was getting a code 33 and a code 36. It ends up all I had to do was reconnect the sensor and clear the codes (unplug battery for a few seconds), and the car started up just fine and ran just fine. So clear that code, and see how she runs..

 

gtaeric, to your original question, yes. Before changing the MAF, replace the relays.

 

A stuck open EGR valve can cause this same problem also, just something else to look at.

 

Hey Eric Did your cars idle problems start before you installed your fuel pressure regulator or after??? when you replaced your regulator did you replace the orange gasket piece that holds the fuel diaphram together???

rob

 

There's a flow chart to diagnosis a Code 34 at the following link:

https://www.thirdgen.org/techbb2/sho...hreadid=199766

Good Luck
Bill

 

Hello gtaeric,

If you had gas coming out the FPR vacuum line going into the plenum, you might want to check your oil to see if it has any gas in it. Just a thought.

 

robsgta, I was having the no idle problem before I replaced the fuel pressure regulator, but I was also then having a no start problem. Both of those problems just "showed up" one day. So replacing the fuel pressure regulator (a new unit with the orange gasket), fixed the starting problem. I have checked all the relays, and they are fine. And I just tried to test the IAC, by pulling it out, working the pintle all the way in, and putting it back in without hooking up the connector. And my problem remained.

 

Well any time you get SERVICE ENGINE SOON and make some changes be sure to unhook the battery for a about 10 seconds to clear your codes and see if the SES comes back on.