My civic has a rough idle and will drop down to really low RPMs and kind of lope, if I rev it and then let off the gas it will die. I think it might be a timing issue. Does anyone know how to adjust the timing on a 93 DX?

Thanks.

 

Warm up the engine and turn it off. Jumper the test connector at the ECU as if you were checking for trouble codes. Put a timing light on cylinder #1. Restart the engine (CEL will come on steady because the jumper is in place. If it blinks out any code, take care of the code problem first). Adjust to the center mark on the group of 3 on the crank pulley.

If you find the timing suddenly way off, the timing belt might have skipped a tooth. Replace the timing belt immediately before it skips again and damages the engine.

 

Also inspect the spark plugs, wires, cap, and rotor and try cleaning the IACV on the throttle body.

 

I found out the miss is in Cylinder 3. I am getting fire to the plug so it isn't electrical. I am going to run a compression check on it hopefully tonight (need to find someone who has it). Oil looks fine, so I don't think it is a head gasket. Any ideas what could be causing it to miss?

Thanks

 

Switch the #3 fuel injector with one of the other ones and see if the problem moves with it -- bad injector.

Valves adjusted too tight? This will show on compression test.

Faulty spark plug, put a new one in even though the old one looks fine.

 

Does a 93 1.5 have individual fuel injectors?

Thanks

 

Yes the DX would have a D15B7 16 valve engine with MPFI. I don't know for sure about the 8 valve CX engine.

Very easy to get to the fuel injectors on those, take off the 3 nuts holding the fuel rail. After installing an injector, check carefully for fuel leaks at the rail. Technically you're supposed to use new o-rings every time.

 

I will do that tonight. Thanks for your help MK378. If it is a fuel injector will the compression be normal on that cylinder?

 

I checked the compression and on Cylinder #2 I had 120, #3=60, #4=135. What do you guys think is causing the low compression? Is it a valve problem?

Thanks

 

A leak down test (see compression link in my signature) will tell you where compression is being lost.