npregozen

I have a 98 Civic LX 5 speed. A couple of years ago, the "Check engine" light went on and the car would stall out at intersections. My regular mechanic was out of town and I went to another garage who replaced the front O2 sensor (aftermarket). After that, I became aware that the car would start to feel as though it was losing power ( at about 55 mph) for a few seconds, and then surge forward. My mechanic thought that it was a fuel issue. He then replaced the injectors (i ordered them online - aftermarket). The injectors ended up staying up in the very rich range most of the time. I ordered another set that are better, although still perhaps abit in the high range (the reading is apparently in the 70's but does drop down immediately upon decelaration). He also replaced the catalytic converter and both O2 sensors (all aftermarket) based upon codes and info that was coming up on the scanner.

The check engine light still comes on and the code shows it running rich. The freeze frame at the time the light comes on shows a very low rpm rating (160) which is why he thinks that the "rich" code is showing. He has checked the distributor, wiring and sensors, and is now is wondering about the computer. It shows abit of moisture damage on the outside but looks fine inside.

Any thoughts or insights would be appreciated.

laack

first off, what are all the current codes? That will be a great help in narrowing it down. autozone/advance auto/etc scan for free.

You took somewhat of a reverse order of replacements that i would have, but by someone else's recommendation so i cant blame you.

does it idle low all the time, intermittent, only when warm/cold? does it hesitate at all during acceleration related to rpm range in addition to 55mph?

with a couple questions out of the way, this is where i would start now that you have the expensive attempts done already.

• fuel filter- done yourself for $9 and 15 minutes of time (there are multiple diy's on here and youtube for guidance if this is new to you)
• Check ignition timing- may not be your case, but i battled this one just a couple weeks ago and it fixed a slew of problems. (many DIYs on youtube. expense to you if you dont have a timing light gun is $40 at any autozone/meijer. cheaper if you get one on ebay.
• Idle Air Control Valve IACV- its a b$tch to get at in this car, but if you let the engine warm up and disconnect the p2 connector (electral connector) you will hear the idle rpm drop somewhere in the range of 400 rpm. if there is no change when you disconnect it then your iacv has failed or all gunked up. less likely but a FREE test to do. pain in the *** though.
• MAP sensor- pick up a can of cleaner at autozone and spray it down-again plenty of DIYs
• *someone correct me on this one- im not sure if a bad PCV will give a lean or rich code but its a cheap fix in the 3-4$ range. also a pain in the *** to get at.
• valve lash- if it hasnt been done in a long time, its due anyway but improperly adjusted lifters can cause a too rich/lean code. im sure you engine would sound like a ticking sowing machine by this point if they were the problem but its free if you do it & around 100 if the shop does.
  
  
• tougher one to check is fuel pressure, no one rents testers out so you would have to purchase one. likely cheaper to have the shop do it.

thats all i can think of off the top of my head, but if you are mechanically inclined you can knock all of them off the list in an afternoon. trouble shooting 1 at a time would probably be cheaper but more time consuming. reset the ECU and do idle relearn
(go for a drive to warm the engine first. turn off all electrical/lights and heater. shut off ignition. disconnect battery for a couple minutes then reconnect. then start engine with radio/electrical and heater off. let it idle for 10 minutes with out turning anything else on. turn car off. then go for a short drive) this will let the computer relearn fuel trims and try to set idle to 750 rpm. all codes will be erased from memory also, so when the check engine light returns, if it does, it will display all the current problems that you have.


wow that was lengthy

londonhogfan

May not be the same thing, but mine is just shutting off randomly. Turns out there is a recall for a lot of the 98 civics and the dealer will replace your ignition switch.

http://www.automotive.com/1998/49/ho...alls/9687.html

npregozen

The only time that the idle seems to be low is just when the freeze frame of the scanner shows that the check engine light came on. I don't always see when it goes on but it seems to be after the car has been running for a few minutes. The car hasn't lost power during acceleration since some of the parts were replaced. I don't notice any obvious hesitation during acceleration. The timing was checked when my mechanic tried another distributor to see if that was the cause, which it wasn't. Fuel pressure is fine on scanner. Is it necessary to check independently of that - or was that if it was still losing power?

I mentioned the ignition switch recall to my mechanic, he didn't think that could be causing this problem but I will call the Honda dealership and ask.

I will speak to him about the other suggestions.

Thanks.

laack

what codes are you getting? i would guess P0172 for the rich fuel, but are there any additional ones? that may change some of trouble shooting.