zaltounian

I have a stock 1998 Civic Ex, with about 206K miles on it. about a two months ago, I replaced the spark plugs, wires, distributor, mass airflow, all belts, and water pump. Nice little tune up. Recently the car has been running a little sluggish at start up.

When the car has been sitting for a couple hours or overnight it starts up little rough. The idle is not steady. After about 30secs everything runs fine. I have no power loss and the car runs great while driving. I only have an issue at start up after it has been sitting.

I am thinking some gunk might have the fuel injector sticking and they are not closing all the way, which is allowing extra fuel into the cylinders while the car is off. Before spending $150 on new injectors, is there a way to confirm it is the injectors that are the problem? Or maybe there is another problem?

Thank you,

Zaven - "Z"

zaltounian

Just ran the scanner and it is throwing up alot of codes.
P0301-P0304 - Each cylinder is misfiring
P0300 - Random/Multiple Cylinder Misfire
P1399 - ICM

Dan_99_Civic

I have a '99 Civic EX, D16Y8 engine. Had same codes (P0301, P0302, P0303, P0304, P0300, P1399). Was running really rough, and CEL was flashing some of the time. Happened quite suddenly on my way to work yesterday. At high RPMs was less noticeable, at idle it was barely noticeble if at at all, but under load at lower RPMs, it was pretty rough. Had been a little sluggish before that when pushing gas pedal hard at low RPMs (in too low of a gear), but not bad, and no CEL before yesterday.

Plugs were bad (large gaps, rounded electrodes), so changed them. Bought plug wires but didn't install them since the old wires looked good and measured good resistance (I had bought nicer NGK wires, so they were about $60, and I thought I would save that money by taking them back later). After a day's worth of trying to find something else wrong (fuel pressure checks, replaced fuel filter, then cap, rotor, and eventually the entire distributor since I think I broke something on the old one when I was getting the old rotor off) I finally installed the new plug wires this morning. Car runs perfectly now after a couple of drives.

On internet searches found various people with similar error codes that were NOT fixed by the plug wires, so I guess I got lucky, after being kind of dumb for a while.

For completeness, should say that I messed with the IAC valve. This is one of the 15 things that the repair manual said to check when getting the misfire codes. Pulled it off the car (don't spill too much coolant when you take it off!) and applied 12 V across the two leads. Could see and hear it popping back and forth okay. But can't imagine that it had a lot to do with the problem, since the car was idling okay, and the total amount of air it lets through looks like it's pretty small compared to when the throttle is open. But, I did not start up the car after messing with the IAC valve, until after I had changed the plug wires.