Rough Idling

[clemson99]

I recently got my car out the shop. I got the cam shaft and crank shaft seals replaced. Timing belt kit and the timing belt tensioner replaced. Now I am getting some up and down idling in my car. She is a 93 J30. Once I'm wide open on the road there's plenty of power but from a stand still and pressing the gas there is a lag and the rpm is low unless i really hit the gas then it seems the horsepower comes alive. I just got the injectors cleaned saturday and the issue is still there. I will be taking it to my mechanic but I need an idea before I get there. I know I'm not the only one this has occured to and there are plenty of experts here on the forum.

[yodawill2000]

Make sure all the intake hose clamp are TIGHT.
I had the same lag thing on my last tbelt change and the clamp for the passenger side throttle body was loose.(Vacuum Leak)

[clemson99]

thanks Yoda I will get it checked out.

[yodawill2000]

If you have a socket set you can check yourself . 5 min max

[clemson99]

can you point me in the direction of which vacuum hose i should check? i do have a socket set.

[yodawill2000]

I was talking about the plastic intake tubing.
There is a clamp at each spot that two pieces mate.
Mine was leaking right where the intake clamps to the throttle body.

[clemson99]

Last night looking at it. I was able to shut the car off by just bending and moving the wire that goes to the plug for the mass airflow sensor. My mechanic is looking at that now and checking the hoses for leaks and tightness. One of hoses near the battery should be a 90 degree hose but a regular hose was used and it gets real thin at the bend. He will get that replaced also and continue looking. What would cause the mass airflow sensor to go bad? Do you think that would cause the idling reving low and high?

[yodawill2000]

That's normally a stick IAC valve.
But the MAF harness can cause fluctuations as well.

[clemson99]

my mechanic found a lot of corrosion in the plug portion of the MAF. That has been cleaned out and they also found 2 vacuum leaks. They are going to go drive it around some more to make sure they have figured this out.

[clemson99]

How hard is it to get to the IAC Valve? i have had everything else checked but the IAC. I had one master tech turn down the job. my mechanic can't do it and is trying to find another guy in town to look at it. how much should it cost on cleaning the IAC and how hard is it to get to?

[GerryO]

http://www.mdsmarthome.com/z/Z%20Tech/Z ... 20Idle.pdf