Hello- Long time lurker, first time posting.

Been messing with Hondas for several years, but this one has me stumped.

So the background.. My son traded his 90 Accord coupe for this 94 a few weeks ago. When he got it home, it would barely run (pretty well screwed on the deal). It had oil in the plug wells and the CEL was on. Replaced the rocker arm O-rings, plugs, and wires (PO had just put a new dizzy in). Replaced the O2 sensor (with Denso), TW sensor, and VSS, and cleaned the EGR ports to take care of all the CEL codes.

It ran good for about two days, except that it would die when you braked to a stop. It also started bucking and lurching at about 1/4 throttle. I recognized this a bad TPS, so changed and calibrated it, and that took care of that problem. Also cleaned the IACV and FITV while I had the throttle body off. While driving it for those two days, I also noticed the brake MC was starting to go, and would leak down all the way to the floor if you held constant pressure on the pedal. Off to the parts store again...

When I took off the old MC I discovered that the seal was totally gone between the MC and booster, so I figured that was the dieing issue. New seal in place, the car once again ran great, with no dieing at stop signs.

Another few days later, my son took off for a Saturday night cruise, and it starts dieing again. Now it even dies when you just push in the clutch.

We pretty much spent all day today trying to pinpoint the problem. It will start and run fine when cold, but as soon as it idles down from fast idle. it starts to sputter and die. The only way it will idle is by screwing the bypass screw out about four turns. We tried changing the IACV out with a known good unit, but that didn't change anything. Like I said, I'm pretty much stumped at this point. Any suggestions?

 

you more or less answered your own question, runs fine when cold (open loop) and dies when it warms up (closed loop). Must be an issue with sensors or the 02's once in closed loop. Wouldnt hurt to test fuel pressure either

 

Is there a take-off point for fuel pressure testing?

O2 new and showing correct voltage. TW sensor is new, too, but I haven't checked output on it.

The car runs great on the road at anything above an idle.

 

hmm anything but idle? Is the fuel pressure regulator operating correctly? yes Im not sure exactly. I would assume the fuel rail is a point to look at. MAD MIKE would know better. My prgram isn't working so I cant check

 

First, thanks for the reply accordturb96.

I downloaded the service manual yesterday and did some reading. The troubleshooting flow chart points to four possible causes for low idle:

1- IACV
2- Fuel pressure regulator
3- Injectors
4- ECU

The IACV has been ruled out. After I thought about it, having to open up the air screw so far to get it to idle would seem to indicate too much fuel is being injected. I saw a low mileage 94 at the local U-pull the other day while scrounging for 325i parts, so I might just pull the entire fuel rail, FPR and injectors to cover items 2 and 3. Looking at their online pricing, $30 will buy the whole assembly.

 

no problem buddy. I think swapping some of those components would be a nice cheap way to go. May be something simple in the system causing issues.

 

I followed my plan and swapped out the whole fuel rail assembly. Started it up and let it warm to operating temp, and it idled down just perfect. The idle speed now responded to adjusting the air screw, where before it wouldn't.

Off for a test drive and everything was perfect. Stopped numerous times, and every time it would idle just as it is supposed to. Headed home, and on the long hill down to my driveway I let off the gas and let the engine slow the car before braking. As soon as I pushed in the clutch to hit the brakes, the engine died.

It started right back up, but would not idle unless you kept your foot on the gas, and even then not very well. I finally got it to barely keep running, and got out and popped the hood. First thing I noticed was a weird high pitched vibration/squeal. After listening around, I finally figured out it was coming from the EGR valve. I popped off the vacuum line, and like magic the idle raised right up to where it should be! So, I'll be heading back to the U-pull to scavenge the EGR valve and EGR solenoid from the car I pulled the fuel rail assembly from. That would have been a fantastic car to have gotten a hold of before it was wrecked...a 96 with only 125k miles on it.

 

haha **** man. Glad to hear you're slowly getting it back together.

 

hello guys I have 2002 Honda Civic it start then stalls right away I change the fuel pump and the relay too but no luck