MisterTea

Hey all,

I am new to the forum so this is my first post.

I have a 1995 Civic EX, 1.6 VTEC and 5 speed manual. Mileage is 179k on the clock but the previous owner says its closer to 250k.

My problem is as follows:
When cold starting the engine idles quite rough and there is a strong smell of gas in the exhaust. If I don't allow the car to warm much, while driving the engine rumbles as if its missing and power is low. It sometimes surges a bit as if the engine is starting to operate normally. By the time it gets warm the rumble goes away but it stutters while driving every few seconds no matter what gear or speed I am running. During idle (at a red light for example) after fully warming up it idles normally but the idle drops a bit, the engine rumbles and then the idle jumps back up. This repeats every 5 seconds or so during idle but the idle does not run too fast, appears to be around 600-800 rpm.

If I let the car warm for lets say 10-15 min before driving then the engine behaves as it did in the paragraph above when at full temp. So it appears that it is temperature related. This problem also coincidentally started two weeks ago during the first few days of freezing temperatures.

I did a tune up about a year ago: new cap, rotor, wires and plugs. So they should still be good. I was told it could be the IVAC but I would like a better diagnosis before I start replacing/cleaning parts to fix the problem. Plus its cold as hell in NY and I don't feel like spending too much time outside under the hood

Thanks

marcelosm

The IVAC is extremely easy to remove and clean. You don't even have to take off the throttle body to get to it.

TomCat39

When is the last time you checked/changed your air filter? If it's clogged the car could be starving for oxygen.

And I too second the IACV clean out or at least check to rule it out.

marcelosm

You might wanna clean out the FITV and adjust it again as well. You could also look for vacuum leaks as well

MisterTea

Thank you for the replies. What is the FITV?

MisereNoire

Fast Idle Thermo-Valve, its the module bolted onto the bottom of your Throttle Body.

MisterTea

Well I found my problem. Honda guy at work popped the hood with me and first thing he did was pull each cable at the plug end with the engine running until we found that the 3rd cylinder wasn't firing. The cable sparked as it should againt a bolt head but the cylinder itself wasn't firing. I pulled the plug during lunch and this is what I found:



My guess is when the engine heated up the crack closed up due to expansion but was still loose enough to stutter often. Off I go to buy a new set of plugs, maybe this batch was faulty so I don't trust the others.