Hey folks,

I'm at my wits end on this one and i really need some help, for which I will be deeply grateful.

97 honda accord SE, 2.2 4cyl, non-vtech, auto-tran, 180k miles

I have an intermittent loss of power that acts like a fuel pump going bad, except it will backfire through the intake when the power starts to fade and you give it more gas. Then it will launch. Happens more often after its at full operating temp, but has done so when pressed hard when not fully warmed up.

Had a P1491 code that didn't light the mil/cel. After tinkering with the egr valve the system will light the mil/cel light. Disconnecting the vacuum from the entire egr subsystem (egr valve and solenoids), the car will start and run to full warmup three times before it sets the mil/cel, so I'm guessing my ecm is still good?

Disconnecting any vacuum line will improve the problem. I've tried disconnecting all the different vacuum lines, and the associated electrical connectors. Still does it.

It does Not have a knock sensor, does have the vacuum assisted tranny mount. ???

Gas mileage more like a Chevy Suburban than a Honda.

I've replaced:

Fuel pump, fuel filter (more power),

Crankshaft and injection sensors (a little more power - balance shaft pulley was a bit rusted and had rust dust on the cps),

cleaned inside of distributor and replaced O-ring (it was leaking, a little), cap and wires (rotor was fine -- so were wires and cap,but...),

Valve cover gasket

map sensor (power improved -O-ring i guess --problem did not),

o2 sensor

ECT temp sensor (had a little oil in the connector). no improvement.

Timing belt was replaced 20K ago - original owner changed it at 60k...

Some vacuum tubing has been replaced -- did the ole flammable chemical spray over all the hoses, engine didn't speed up. Used flammable break parts cleaner, like an idiot -- fortunately no explosion or fires...

Replaced egr valve gasket. Nothing seemed strange.

I've ran a couple of tanks of non-ethanol through it -- better power but no cigar.

Seems the problem started as a gradual loss of power over a couple of years and has recently grown to the stage of "el-buckaroo". At times, if you don't let off the gas when it does it at 70mph, it's so bad you start worrying about breaking the timing belt...

Tach stays steady when it does it in regular driving above 40mph. I guess that rules out the ignition module in the distributor?

After plugging the egr vacuum line, I was climbing a hill today after turning left at a stop light, and maintaining steady gas pedal, it went from fade to mini-launch to fade to mini-launch several times. @ about 20mph, 2200 to 2800rpm.

I have scoured forum after forum after forum, alldata (yeah, right).

Anybody have any answers on this one?

(((I just thought of something... the egr valve could be intermittently opening up maybe???. even with no vacuum applied? Yeah, I know I'm probably reaching, but I'm desperate...)))

Again, your help will be tremendously appreciated!

Thanks, Ernie

 

Ruptured FPR? Check the vacuum hose for the FPR; there should not be any fuel in there.

 

Maybe I'm missed it, but are the four EGR ports clean? Bucking/poor throttle response while cruising at ~2K RPM is a classic plugged EGR symptom.

 

pop your egr open and drive like that, report back if power returns

 

Hey guys, thanks for the advice. Fpr is good. Power is good at all times when it's not misbehaving, i pulled a vacuum line, introducing a leak, instead of pulling the egr, it improved power but the problem remains the same... Haven't cleaned the egr tubes but I'm going to as soon as the ground is dry. Friday i hope. But... Now, when it is at full op temp, it will not idle after I've romped on it. A little hard starting, and holding the peddle down, it had a spitty idle, almost to the point of a cylinder misfire. When it cools back down, idles fine. I'm going to pull the icm and have it checked and report back. Unless someone knows a better thing to do...

 

The symptom you describe indicates a lack of exhuast gas recirculation. Pulling the vacuum line disables the EGR valve...the opposite of what you're trying to diagnose.

 

Gotcha. I'll post back as soon as I get those passages clear. May be Monday as I got extra stuff dumped on my worklist and the weather this weekend is abominable for us weather wimps...

thanks Roader!, E.

 

Hey foks, cleared the egr passages thoroughly. After warmup, would not idle below 1500rpm and is a nasty idle at 2800rpm. Unplugged egr valve and control solenoid from electrics and vacuum, seems to run fine -- Gas mileage has GREATLY improved -- Thank You Thank You Thank You! Next I am going to install a template made from a cola can to block egr gases, hook everything back up and test.

You know, used to be when an egr valve failed you just kept going until you felt like dealing with it. My 93 ford modular 4.6v8 is like that but my 95 ford modular 4.6v8 chokes, gags, spark knocks etc when the egr is blocked. Our old 4.3v8 Chevy caprice didn't care -- just unhook the vacuum line and we were good to go...

Eh, the woes of OBDII...

Thanks again guys, yack back at ya soon. E.

 

I'd double check the vac lines. Make sure they are connected and on the correct line - meaning if two got switched then vac to the egr could be on at all times.

Next, check for vac leaks around the injectors.

Last, let the ecu relearn idle.

 

My FI '88 Ford pickup with a 300 six (OBD0) pings like crazy if the EGR is disabled. EGR allows higher compression and more spark advance while using lower octane gasoline.