View Full Version : Idle problem (yes I have searched)

11-02-2009, 08:35 PM
My wife has a 2003 Mazda B2300 with the 4cyl 2.3L engine. The other day it developed an idling problem, I popped the hood and could hear a misfire. The CEL came on, I didn't have time to work on it so I took it to a shop. They pulled the code and it came back as a misfire on one of the cylinders. He changed the coil for that cylinder but it didn't fix the idle problem though the CEL went off and it fixed the misfire problem. I have done some searching and came up with a check list of things to look for. Them being: check MAF and TPS sensor, IACV, and timing. Is there anything else I can look for? It drives ok but when you are stopped it idles rough. The mechanic at the shop also replaced one of the O2 sensors but that didn't solve the idling problem either. Now he is thinking its a burnt valve or a broken spring. Something that is strange is that when you first start it and put it in gear to move the brake pedal is mushy the first couple of times you press it. After that its fine. Could that have something to do with it, maybe a vacuum leak? Also, do any of you guys have a manual in .pdf by any chance for for this truck. Any help is grately appreciated and thanks in advance. -J

11-03-2009, 07:30 AM
Timing is nonadjustable. Only way it could be timing is if the timing belt was slipping and about to break.

I would clean the MAF also look at all vacuum hoses. there is a diagram on the front of the truck when you open the hood

11-03-2009, 10:38 AM
If it is only symptomatic at idle, I would focus on idle related things first.
- MAF cleaning
- IAC cleaning
- Throttle body cleaning
- Air filter clean?
- Fuel filter replace
- Vacuum leaks, disconnected hoses and connectors
- Plugs (start with the cylinder it said was bad)

Do all that and I bet your problem goes away, mostly for free.

11-04-2009, 03:25 PM
Well the mechanic at the shop I took it to can not seem to figure it out. He is leaning towards a burnt valve or a bad spring. I brought it home and unplugged the MAF and it seemed to idle correctly for a minute then went back to the rough idle. Also I can hear a popping sound coming from the engine. Does anyone know what this could be or experienced this problem before. I really do not want to take it to a Ford dealership but it looks like I am going to have to.

11-04-2009, 03:37 PM
You cant just unplug the MAF and expect it to work right. MAF is there for a reasson

11-05-2009, 04:05 PM
Actually ford had a recall on there iacm on the 2003 rangers. I don't know if Mazda is doing the same thing since, Mazda is Ford. But one of the test's to see if the iacm is going out is. If your truck is having a hard time starting put your foot just slightly on the gas then try to fire it up, if it fires right up then its the iacm. I dont know if that helps but FYI

11-06-2009, 09:31 AM
The truck starts right up everytime. It just idles like crap. Its currently at a Ford dealership, they have been running tests but have yet to figure out what it is. I will post their diagnosis when I find out. Hopefully it may help out someone in the future. Thanks for all your suggestions and input.

11-07-2009, 10:36 AM
The guys at the dealership have diagnoses was bad power control module. Which is located on the passenger side firewall.

10-26-2010, 08:31 PM
This is my problem exactly. I am hoping this is it. But thanks for posting either way. I will update if it was my problem too