The answer is too involed to list here. You need to purchase a repair manual at most auto parts stores. Also replace the timing belt at this time unless it was replaced within the last 50,000 miles.
how to replace the water pump on a 1998 Honda Accord
How much does it cost parts and labor to replace a valve cover gasket on a 1990 Honda Accord 4door.
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no
The 1990 Honda Accord does not have a cabin filter.
It is located in the fuel tank. The tank must be removed to replace it.
no
THE WATER PUMP ON THE ACCORD IS DRIVEN BY THE TIMING BELT AND YOU WOULD NEED TO REMOVE AND REPLACE THE BELT AT THE SAME TIME AS THE WATER PUMP
EM 6279 and EM316. Which of these works for my HOnda accord 1990 EX 5-speed?
how do you take out a transmission on a 1990 Honda accord
For more complete instructions, see: http://www.faqfarm.com/Q/How do you change a front corner lamp on a 1990 Honda Accord LX
If you haven't replaced the relay, check this website. It will show where it is located and how to replace. autorepair.about.com