I have a 1998 civic 1.6 auto with 209,400 miles. This was my neighbors car till it started having issues and put it up for sale cheap.

The cars issues is loss of power under medium to heavy acceleration, like its bogging down like a bad O2 or MAP sensor, or like it has no vtec, light acceleration is fine, but you can't take it on the interstate as it will not go over 45MPH up hills. The other issue is it stalls 2 times after starting it, not 1, not 3 or more, but 2 times while driving it within the first 10 minutes, after that, it just does its bogging thing but will drive fine all day.

My neighbor said it just started doing it one day out of nowhere, he had the vtec solenoid and sensor replaced, new cat and fuel pump installed, i have replaced the fuel pressure regulator, distributor, MAP sensor, throttle sensor, idle sensor, muffler, O2 sensor and had the valve lash checked and it still does it.

Car does fine going to from work, no check engine light or codes, just have to deal with stalling 2 times and what fills like a 30HP car.

Anything else i should check?

 

^^^ THIS!

 

So, the car had already been to two shops, our shop you could tell was not sure but wanted to through parts at it and charge us for it, same as the place my neighbor took it to, so at that point, why pay them to do what i could do. So i took it to another shop, told them to check everything as you said, they came back with "the engine is just worn out" and need to replace, so thats a new one.

The cars not worth that by a long shot, and i don't believe that anyway. I have no proof, but i swear it has something to do with the Vtec system, but i don't know how it works or how to test it right, everything for the Vtec system has been replaced, and still no change, but the engine runs so good, just that roaring noise from the intake and loss of power at higher rpms.

At the end of the day, its still a great backup car, i could drive it everyday, just not being able to use the interstate is a pain, but at this point, no shop can figure it out so this might be the end i guess and just drive it as is.

 

OH, and forgot to mention, we figured out the stalling issue, it was a bad main relay behind the glove box, replaced and no longer stalls anymore.

 

For the power, I would check to see if the timing is screwed up, maybe jumped a tooth, sounds kinda like that. But you can scan the car also and drive it to see what the timing thinks it's at, also then you can double check other items like O2 to make sure they are ok (I know you said they were replaced, still can't hurt to look at them to make sure).

 

Alright, so we got invited to a friends party this weekend, one of their friends had the same civic, year and everything. We get to talking and i run back to the house and swap cars and we start going through stuff under the hood (he's car runs great) and what do you know, we find the problem, I know they didn't have much power to begin with, but you could tell a big difference between mine and his car.

The metal tube going into the rubber intake was clogged with dirt (mud daubers more than likely) How, IDK but it started running better, but now after that, you could here a very loud vacuum leak, so we find this little hose coming off one of the heater lines next to the top part of the transmission was pushed down under a wiring harness, for now, we plugged it because we can't seem to find where it goes and he's car doesn't have that, BUT but, it runs so much better now. took it on the interstate today and she hold 60 going up the hill, something it could not do before.

So, how did mud get into the metal tube IDK. why was there a hose not plugged into anything causing a big vacuum leak that once the mud was cleaned out IDK, why did 3 shops miss this IDK either.

So i guess now, if anyone out there knows what a little vacuum line coming off of what looks like a check valve thing on top of one of the heater hoses (the other line goes the top back part of the engine) i can't find anywhere that it would plug into, that would be helpful, but other wise, she is fixed in my book.