unded95

I recently purchased an 98 civic DX with auto trans that is having some issues.

What it does: Takes a couple cycles of cranking or combination of cranking a sputtering. Once running it will idle fine till warm. Once warm it will continue to idle ok but seems a little low and will begin to vibrate. While not in gear it seems like a good runner but, in gear and driving is when things change up. Cold driving or driving until operating temp, the car accelerates just fine. The down shift is not a smooth change and very noticeable. This is a bit concerning for me as the car will jerk forward when it happens. Along with this its as if there are sweet spots in pedal position to get the car to accelerate. It gets worse until the car gets to operating temp. I discovered that if I quickly feather the pedal while accelerating it helps. When trying to get to highway speed or accelerate quickly it will fall on its face and or downshift with little to no acceleration and max out the speed for that gear, engine will be at a high rev and not shift unless I back off throttle. Finally now and then I hear a buzzing around the throttle body area. There are no other underlying issues that I have noticed.

CEL codes: When I first got the car it was giving me code's 1,7,10, and 14. Now and then 5 would come up but after reading through a few threads I found that is often a false code. After replacing a few things and an attempt at an ECU reset it now only gives out codes 1 and 17. The speedo didn't work from the get go but my better judgment says this shouldn't effect anything.

What has been tried: the person I bought it from replaced, fuel filter, air filter, plugs/wires, main relay, o2 sensor, and I belive the ECT (it looked to be fairly new) and was told they attempted to check the cat with no change in symptoms. Sense in my possession I have replaced TPS, Air temp sensor, swapped a MAP,(just to try, currently back to the orginal) cleaned and tried factory and a replacement IACV. Because of the shifting issues trans fluid was checked and topped off just in case but, with no change. I have also ran a compression test and ran a cycle of sea foam. and yes I checked coolant for any sort of air bubbles.

Next on my list to try is the timing, ICM, or injectors. I question the injectors because of the buzzing around the throttle body. I haven't tested the injectors because i just haven't gotten that far, and don't know how. Have not tested the timing because I don't own a gun/light for that. This is the first Honda I have ever owned and would greatly appreciate some advise or a hint if I am on the right path to finding the issue. I can't throw in the towel because I purchased this car to get around for work which sends me all over town throughout the day, and my dying full-size chevy isn't cost effective unless I restore it or set it to pasture so I need this running properly soon!

Thanks to all who took the time to read ALL this! I just wanted to make sure I didn't give any choppy or vague info.

jonGSR

As long as the mechanical timing is set the car will still run fine. Using the gun to set the ignition timing will get it perfect but is not necessary for the car to idle and run fine. I've done many timing belts and had the car running before using the gun to set the ignition timing so you can rule out that.

Are you sure you're not getting a code 10 still? IAT sensor? I had one that was bad in a 90 DX and that car would give me all kinds of problems when cold.

A code 1 (o2) and 17 (speedo) won't affect how the car runs. It should still start and run fine.

Double check the IAT.

jonGSR

I forgot to mention to check the wiring for the auto lock solenoid valves. They are located on top of the transmission under the distributor. See if any of the wiring has been mangled and possibly have a bad connection.

unded95

I guess I will now nix the timing and yes, I have replaced the IAT. I got home yesterday after work and realized that while my buddy was going over the vacuum lines this past weekend he unplugged one from the choke plunger to an electrical connection on the other side of the throttle body. If that choke isn't opening properly makes sense that the car is running the way it does. Now mind you it was running s&*@y from the start. On the electrical end of this, is what goes into the throttle body a temp sensor of sorts and could that be my source of problems.

Bently_Coop

Faulty O2 sensor will dump fuel. Pick up either a NTK or Denso sensor for replacement.

unded95

I tried the o2 sensor and there is no change. I am still thinking it has to do with the sensor that is part of the vacuum for the choke.