I'll start with all the events from last few days. Car died while being driven. From what i was told it just lost power and when they pulled over the engine just sputtered to a stop. I first tried changing the fuel filter and that didn't help. I took a guess that it may have been the pump because there didn't seem to be any pressure building up and i couldn't hear the pump running. I replaced the fuel pump today and was able to get the car started. At first it ran great but when i took it up the road it started to lose power. I was able to get it home where it died in the driveway. The car will start and idle now but any time i give it more than just a tiny bit of throttle it bogs down and if i dont back off the pedal it will die. About 2 weeks ago i did a tuneup new wires, plugs, cap and rotor and the car ran great after that until this happened. I know this is a big post but any help would be appreciated.

 

I have a similar problem with my 97 EX Coupe. When I first get going down the road, it bogs down when I give it a little throttle. I have to back off it for it to catch up to itself then it runs ok until I get to my destination, then It'll do it over again, but only once each starting cycle. If I floor it, it will take a second or two to get going, but if I keep the throttle at the same place when it's happening, it takes about 4 or 5 seconds to get going. My problem is not as severe as yours, Metalhead, but a problem nontheless. Maybe they are related. I did all the stuff you did, fuel filter, pump etc. and same problem. Someone out there must know. Thanks.

 

I'm not sure either... but I'm guessing either there is TOO MUCH fuel, or NOT ENOUGH air to properly burn. After all, an engine requires a proper air/fuel ratio to run properly. My guess (in this case) would be a fuel regulator - because in both cases here it seems to run fine at idle but as soon as more fuel is added the engine bogs out.

Both of you - have you done a complete tune up recently (Cap/rotor/plugs/wires)? If not, check into that to be sure you are getting a good spark to ignite the mixture in the cylinders.

 

I did a complete tuneup just 2 weeks ago. car ran great afterward until this problem started. tomorrow im going to take the fuel pump back out and check it to make sure i put it all together right and check the fuel filter also. i really thought it was just the pump. the strange part was right after i changed the pump it ran fine until i went up the street with it. then it tried to die when i was about to turn around and go back to the house.

 

Then maybe you've got something clogging the fuel line between the pump and the engine (likely between the pump and the filter). if the pump works properly, you've got flow problems. could even be that you got a bad fuel pump out of the box - but that's pretty rare. check for ful voltage at the pump's wiring harness. I also believe there is a D.I.Y. on checking fuel flow on this site somewhere.

If it only started after you changed the fuel pump then I would start with that.

 

Yep, did the complete tune up thing. This fuel regulator you speak of...is it on the fuel rail after the filter before the injectors? I'll try that next. Thanks...and by the way, in an unrelated topic, would you know if the sunshade on the EX is connected to the headliner or the sunroof mechanism. Doing a new headliner and was just wondering if the shade will come out with the liner or do I have to pop out the glass to access it.

 

Civic - the fuel regulator is on the fuel rail with a vaccume line running to it, its a circular shaped deal.

Sunroof is connected to the roof itself. I've never taken one apart, but I would think the sunshade would come out after the headliner is removed.

 

The pressure regulator is on top of the fuel rail on the right (passenger) side. It works by allowing excess fuel to return to the tank after the proper pressure has been reached in the fuel rail. The pressure varies with manifold vacuum to maintain a constant pressure difference across the fuel injectors. It will increase when the throttle is opened because manifold vacuum decreases (higher absolute pressure in the manifold).

To check fuel flow, disconnect the return hose (that starts from the regulator) at the firewall where it connects to the metal line that goes back to the tank. (First loosen the gas cap to relieve any pressure in the tank). Direct the hose into a container and turn the key on but don't start. Fuel should flow out rather rapidly while the pump primes. If it just dribbles, there is a problem.

Checking the pressure with a gauge would be even better. If pressure is correct, look for other causes of not running right.

 

Any CEL codes?

 

No CEL code here, but while poking around the fuel rail area, I noticed a vacuum line that runs from the throttle body down thru the rail and ends up by the oil filter. With the engine running, this line is collapsed flat, pinched closed by vacuum. With the engine off, it regains its normal hose shape. Would this have anything to do with the problem? Going to try the reg test today. Thanks!