For the last three monthes my 90 civic has acted like it has water in the gas.It started as just the occasional put, put, stalling, put your foot down and it would take off and run good. It has gotten to the point that it stalls constantly, but mostly when warm. I had some water issues in the gas, but I pulled the tank, had it cleaned, and blew out the lines.

When this problem first started I had an O2 problem code flashing.I checked the connection of the sensor, and reset the fault memory and have not gotten this code again.

I know that the O2 sensor determines the amount of gas to the engine, and could be the cause of my problem.

What are the failuresymptoms of the O2 sensor?
Does it act like water in the gas?
sputter and die?

 

When was the last basic tune up done (plugs/wires/distributor cap/rotor)? You might also consider replacing the fuel filter.

 

The plugs are new, the rotor and cap have been cleaned and checked. the wires look good, but they could all stand to be replaced. The filter was replaced when I thought I had a water problem, which I did, there was a small amount of water in the gas, after I cleaned the tank I dumped the fuel out of the filter and found no water. so I put the new filter back on. there is a possibility that the filter had been exposed to water, but I dumped it several times and got no water.

the fuel pump was suggested as a possible problem, when I took the tank off to clean it, the pump looked original. 18 years, and 190,000 miles.

My only experience has beenthat a fuel pump either works, or it doesn't. I have never had one that ran good at speed, and only failed when at a stop light, just about the time that you get in the middle. If you turn the key off, thenback on you can restart and rev above 2000 rpm and take off again.

At least that's how it worked until the last time I drove it a couple of days ago. It stalled constantly, and was hard to keep running. Oncemore mostly at low rpm, but harder to keep running in general.

Do these sound like the symptoms of a failing fuel pump?

Thanks
Dave

 

You'll know whether the fuel pump is suboptimal by measuring the fuel pressure (see manual).

You also may want to multimeter test the plug wires if they are old (see manual).

I would also recommend that you troubleshoot the distributor coil and igniter with a multimeter (see manual).

Civic manuals link:

http://hondatech.info/downloads/Auto/Manuals/Civic/

 

I would also check for vacuum leaks.

 

I had to wait until payday to get a fuel pressure tester, and now I have to make an adaptor to fit honda. Then I will be able to test the fuel pump pressure.

My chilton manual says to pull the vacume line to the fuel pressure regulator, and the psi should be 36. This is great for testing the pump, but no instructions are given for testing the fuel regulator.

It says that the regulator holds fuel pressure at 36 psi above maniforl pressure. but does not give what the psi would be at normal idle, or what it would be at say 3000 rpm.

Knowing what the fuel pressure should be at idle, and at higher rpm, would be a good way to trouble shoot the regulator

Checking the fuel pump is straight forward.
Any thoughts on checking the fuel pressure regulator?

Thanks

 

 

Thanks for the picture that showed to pinch the return line.

now I am off to the hardware store to try to cobble together an adaptor. No one had a tester that fit hondas, the kid at the parts store works on hondas and he said that what he had to do was take a bolt the same as the one in the test port and drill a hole through it. You can then use a rubber hose to connect.

This sounds like a lot of fun. any thoughts on making an adaptor?