I recently changed the timing belt on my 1992 Honda Accord EX, it now runs rough at idle, I have gone back and checked the T.B. several times to make sure everything was lined up correctly, even went to a mechanic (Not sure if he was any good?) and everything seems to be lined up properly, also my fuel mileage seems to be really bad now, Please help and Thx...!

 

Did you verify that your base ignition timing was correct?

 

When you say rough do you mean there's a bad vibration ?

 

Balance belt lined up right? Did it break before hand or just changed as prevent maint? Valves adjusted?

 

Hi There, yes the timing was checked and is correct, the balance belt and all points are or appear to be lined properly, and NO, the valves have not been adjusted....at Idle it is rough and has a really minor misfire, after passing 1k RPMS it is really smooth.

The belt did not break before-hand, just a complete replacement with all seals, belts, tensioners & springs.
Note: the mechanic did run a compression test and said that all cylinders looked really good

 

Check your spark plugs, wires, cap and rotor. make sure everything is tight, clean and in good working order. Also check to make sure that any ground locations are clean and tight as well.

 

Define what "runs rough" means exactly. Is it a vacuum leak ? Did you make sure to plug back in the pcv valve. What's happening exactly that you don't like.

 

Hey thanks Ghost Accord & HolmesnManny, I will do the checks that you suggested, The rough Idle, meaning it is not as smooth at Idle as it was prior to my T.B. change and now accompanied by a slight misfire...

I will try the suggested checks along with the valve lash adjustment this coming weekend and see if that does the trick, let you know the outcome...Thx!!

 

Don't forget to do the valve adjustment with the engine cold, also disconnect the battery (-) terminal to reset the ECU. Then once you have everything back together start the engine and allow the ECU time to adjust the fuel trims.

 

Contrary to what some people say that I've seen across the forums, a timing belt change does NOT mandate a valve adjustment. When you do a valve adjustment you're simply lining up the cams. This would have nothing to do with the timing belt so it would make sense that a timing belt change would not necessitate another valve adjustment, assuming one has recently been done.

However, if one hasn't been done recently then obviously it's good maintenance.

On a dohc motor obviously you would want to simply make sure each cam is positioned perfectly since as timing belts age they do stretch slightly so you would want to make sure either the intake cam or the exhaust cam(depending on which cam you are currently adjusting) along with the crank are lined up perfectly and they could be off ever so slightly if you just rotated the crank without looking at either camshaft you are adjusting the valves on at the current moment, because of the fact that timing belts do slightly stretch with age.

 

its real easy to put the timing belt on one tooth off, my brother did it on his civic and it did about the same thing, idled a bit rough, and had no power when accelerating, we pulled it apart, reset the timing and it ran great.