Surging ANSWERS

[Bruce Hunt]

I have posted here before looking for anwers to erratic idle or surging of the engine.

I may not be an expert but I have learned a lot about surging honda engines. I thought I would post what I have learned so that others can maybe save themselves a lot of trouble in the future. I own 7 Honda automobiles and I love them but 3 of the seven have had surging or erratic idle behavior problems. This is what I have learned to date:

The vehicle can surge either at cold only, somewhere in between cold and normal operating temperature, at normal temp, or all of the time. Regardless, of when it is surging, there is a solution.

1. I look to see if there is a "Check Engine Light" (CEL) that is displayed on the instrument panel. If there is then that is the starting point. Follow the links that others have shown to locate the blue connector and jumper the ends to decipher the code. Once you have that code locate the sensor or the problem that is displayed.

2. You don't have a CEL that is on but it is surging, I would check all sensor connections and there are quite a few. There are atleast 7 or 8 of them in the injector and head area. Make sure they are all fully connected.

3. Check for vacuum line leaks, there are a lot of vacuum hoses to follow and check.

4. Some people point to the O2 sensor, but I have found that that is possible but there are other things to look at first.

5. I have found a sticky air flow sensor bad before and by cleaning it I have solved the problem. The sensor appears to be riveted on but I have ground them off and they are screws and can be replaced with screws when reassembled.

6. I have removed several of the sensors and cleaned them as well.

7. There are also a couple of sensors that are controlled by temperature of the coolant flowing through them from the engine and radiator. Make sure the coolant is completely topped off to ensure that no air bubbles are in the system.

8. The last thing I have found that really caused a problem is the intake manifold CANNOT have an air leak. The gasket must be in great shape and the manifold itself can not have any cracks in it. DO NOT OVER TIGHTEN THE NUTS on it, but a case of continual surging for me was caused by an intake gasket that was weak. I thoroughly cleaned both the engine and intake parts where they connect and applied a new gasket. Now the gasket I was told would cost me about a $150 dollars, but by going to the auto parts store and buying some great quality gasket material that is the same thickness as the one removed and that is impervious to water, heat, and fuel I was able to replace it for $7. The intake is easy to take off, maybe not for the first time user, definetely doable.

9. Don't get frustrated, but many surging problems are caused by vacuum loss. There is a test that a mechanic can do to basically do a smoke test on the vehicle much the same as a furnace repairman would check for a leak in the plenum on your furnace. It is not expensive to have done and will get you pointed in the right direction.

10. Good luck and if you have other tips for this please add them.