Rep Power: 0

I purchased a used 1993 honda civic that has a rebuilt engine and seemed like a good deal at $1000. However, the check engine light is on with code 14, iac valve, and the car idles very rough when it is cold, and the car stumbles when it is driven even after it warms up. I replaced the iac valve but continue to get the same error code even after clearing out the old codes. I think that I may have a vacuum leak, since when I put my hand over the throttle body the car does not die, but idles way down. The previous owner replaced the tps switch, and took off the throttle body recently. Could this possibly be where the vacuum leak is coming from? My real question is, where do you think the vacuum leak is coming from? I have very little money so it would really help me if you could help me solve this issue. Thanks.

 
Rep Power: 811

the tps is very sensitive and is often not replaced as a single part because it is so hard to calibrate. i would say cut your losses and look for a whole new throttle body on ebay. used ones go for around $50 usually. you can inspect the actual vacuum lines around the throttle body and intake mani, just look for any that are loose or cracked.

 
Rep Power: 0

Thanks for your answer. I replaced the gasket on the throttle body and it cured the vacuum leak, so that is great. It turned out that the previous owner didn't put a throttle body gasket on but just used that blue gasket gunk. However, now the check engine light has become intermittent. If the check engine light comes on, the car drives really rough from 1200 to 1600 rpms. It will cycle up and down really bad, becoming more pronounced as you go up to 1600 rpms. If you are driving the car it jerks back and forth violently. However, over 1600 rpms it takes off and drives fine. The check engine light error code is always 14.

If the check engine light does not come on, the car drives like a champ. Any ideas? Thanks a lot for your answers. Any help that I can get on this would be great, as I am really stumped right now.

 
Rep Power: 811

its really hard to guess, youre gonna have to start going thru everything to eliminate problems. sounds like the previous owner was doing everything the wrong way. just check the usual plugs/wires/cap/rotor/fuel pressure/vacuum lines/ground wires/battery connections/etc.

 
Rep Power: 0

once my O2 sensor failed. when I took the my 96 civic for maintenance, the sensor was replaced at no cost since it is part of the emission control syst. I wonder what the warranty is for the IAC valve?

 
Rep Power: 811

its a very cheap part, but might be covered.

 
Rep Power: 253

I dont think so on a 93. Are u talking about additional coverage that u purchased through Honda or regular warranty. I thought Honda only covers seatbelts for lifetime of the vehicle.

 
Rep Power: 811

emissions warranty for 8 yrs i believe on related components like cat, some sensors, etc. its a federal warranty that dealers would like to keep secret as much as possible. if you bring the car in, they will try and charge you unless you show that you know the law.

 
Rep Power: 0

The O2 sensors as I was told by the service rep at Honda has the same warranty as the seat belts. they are warranted for the life of the car. trucks are not included.
I thought the IAC valve might be covered the same way. The part is not cheap. I called the Parts Dpt. at honda, they said the IAC valve costs $312.
If anyone knows where I can get it cheaper; I would appreciate it.

 
Rep Power: 811

IAC valve isnt worth buying separate. its cheaper to look on ebay for a whole used throttle body that usually goes around $50 and includes all sensors. but usually the iac never goes bad, just gets clogged. have you taken it off and sprayed carb cleaner to remove all the carbon? should work like new again.