idle uneven and check engine light

[sheller]

Hello, <BR>I just got a '92 MX-3 GS and have a couple of issues I need help with. First, the idle isn't always even. It doesn't happen all the time but when it does, the idle goes up to about 1400 and then drops to 600. It then works its way back up to 1400. Also, I've noticed when the car warms up, the check engine light comes on. It doesn't come on when the car is cold nor do any of the other lights come on. The temp reads right in the middle and I've check oil and coolant and both are fine. The last thing is that sometimes when you press the accelerator there is a hesitation before the power really kicks in. Can anyone help me with my problem(s)? Thanks. <P>Steve

[Ramdao]

check the cranckshaft sensor leads or the sensor it self, it may be the problem.

[Maddbuck]

also check for a crack or split on the intake hose.

[tonymx3]

i had a similar problem, check your intake hose!!

[mazdamxstyle]

when I switched my intake and took off the big box and put a cone filter there, there was a sensor on the big box i think its the egr valve ( not fully sure ) then a electronic piece goes into it i think its a vaf sensor which reads some sort of air going in or out but i didnt know i had to have the hoses from the egr sensor on when i put my cone filter on. My idle did the same thing with the hoses not connected to anything. (the egr valve is on the bottom of the big black air filter box) check to see if there are 2 hoses connected to a sensor thingy, if they are check the hoses then if that doesnt work get a chiltons and learn how to check to see if the egr valve is bad or not. im not 100% sure thats what wrong but it could be.

[sheller]

Ok, I took her into the dealership and found some stuff out. There were 3 different warning codes that had been going to the computer. Two of them they said had to do with the plugs because when they pulled them out to do a compression test, they found that 4 of them were fouled. The third was from the EGR sensor. They weren't sure if that was because of a problem with the valve or because it is smoking (the p.o. put 8oz of Marvel Mystery oil in the gas...I'm still trying to get that out of the system to see if I have a problem or not). Last night I replaced the plugs and the car does seem to run smoother, cleaner, and have more power. At the same time I checked the air filter and it was completely filthy. I knocked the heavy dirt out of it and then used a shop vac on it before re-installing it. I'm going to pick up and install a new one tonight. Might this be the problem that the EGR sensor is finding? If not, how much is a new EGR valve? The idle is still fluctuating (doesn't always happen especially when cold). The guys at Corksport said that it sounded like an intake leak. The last things the guys at the dealership told me was that my valve cover gaskets were leaking and would need to be replaced. Would this make any difference in any of the problems I've already mentioned? <BR>Thanks for your help.<BR>Steve

[mazdamxstyle]

it would be smart to replace valve cover gasket only takes 2 hours at the max and is only abotu 30 bucks to do it yourself