First I will start off by saying I have searched for hours. I own a bmw performance shop in CT but work on everything and I can say im at my wits end with this car.

99 accord coupe 2.3l vtec f23a5 208,400 miles

The owner has been complaining of oil consumption problems and smoking, dying at lights lost power and came in with a terrible miss with codes p1399,p0300,p0301,p0302,p0303,p0304 so I immediately check compression to find the cylinder #2 had zero, 1,3 and 4 all were at 150psi(verified with two different testers) I then notice the timing belt has lots of play nearly 2" so I assume there is a valve seating issue or the car running off time for so long has caused a ring problem or piston came in contact with valves. Pulled it all apart to find insanely blocked egr ports and two bent exhaust valves on cylinder number two and the timing belt was about to fail totally and had missing teeth. Also I pulled cylinder 2 piston and there were some score marks on the skirts although the compression rings seemed fine.

All of this said I have a spare f23 from another 99 MT with 120k and offer it as an alternative to the higher cost of machine work and rebuilding original engine. So we replace the engine start up the car all is well then it starts to develop a miss and we wind up with the exact same codes and problem. The only sensors carried over from his last engine are the throttle body and distributor which we have since replaced with a brand new one because of a intermittent ignitor failure. Also the crank and tps sensor are brand new. The engine now has 150psi on all 4 cylinders but has the exact same codes as before with the same symptoms Timing is perfect and all components are brand new.

CLIFF NOTES
-missing stalling no compression and stretched timing
-found two bent exhaust valves number 2 with scoring on skirt
-replaced engine with good running f23a5
-new timing belt/bs belt, water pump and crank/tdc sensor (wiring is fine on engine harness side too)
-new distributor/cap/rotor plugs wires
-good compression
-cleaned egr valve ports
-valves are all in spec
-verified timing
-missing at idle, and wot, if you baby the gas it wont miss in any rpm
-does not mis past 3500 at wot revs

I know this is a lot to handle but I appreciate any insight or help very much.

 

some suggestions assuming that the root cause stayed with the car when the engine was replaced:

what does the fuel pressure read?
is the catalytic converter clear of clogs or internal damage?
try swapping in a known good ECU just to rule that out.

 

-The fuel pressure If i remember correctly was around 35psi, I checked it with the old engine in and it seemed normal at idle. The original plugs did read a little lean though.

-The catalytic converter seems fine, I ran it with just manifold and it still started to miss after warming up just to be sure.

-I was leaning towards ecu but I dont have the computer to reprogram the immobilizer/vin etc and was told that they hardly fail with these symptoms.

 

My few cents are to make sure you have good ckp and cyp sensors. Having said that injectors and the wire to icm is good with computer. I guess ecu is not managing timing so needs to follow that root

 

yeah, specs are engine idling 38psi-46psi fuel pres reg vacuum hose attached.
47-54psi hose off.
verify fuel return line not clogged/ restricted.
verify vacuum hose on fpr.
and look for corrosion around the ecu sockets/ ecu plugs.

if the fuel pressure does not increase when the vacuum hose is disconnected, aply 12 to 14in of vacuum using a hand held pump. if pressure drops repair vacuum source, if it does not drop replace regulator. got that from the Haynes manual.

 

Okay retested fuel pressure with the banjo adapter, 39-40 psi at idle, 49-50 with line off regulator, fluctuates when i hit throttle a bit so everything seems fine there.

The ckp/cyp sensor is brand new.

 

I am going with a bad ECU. I have two.
One does not like the CYP sensor at all. I bought a new distributor, checked all the wiring and the ECU simply does not like the CYP sensor. CEL right away.
The other ECU has no problem at all with the CYP, it works just fine and no CEL. This second ECU however, does not like my EVAP solenoid. I get a CEL that I cannot get rid of no matter how many EVAP solenoids I swap. The other ECU has no issues with the EVAP Solenoid.

So, it is very likely you have a faulty ECU that simply will not work correctly.

 

Well I don't suspect ecu as they rarely go bad. If sensors are good then narrow it down to wiring of icm and timing related because you have dOne the rest

 

You sound like you know some stuff so I feel silly asking this, but did you clear the original codes ?

 

Did you check pulse to all injectors? Use noid light...make sure pulse is nice and steady? Did you clean out EGR when you installed engine? Maybe got some carbion sucked in? IACV nice and clean?

 

There are no intermittent cyp/ckp codes right now, just the p1399 and p0300. I have cleared the codes many times and unhooked battery, checked injector harness ground to intake manifold and main grounds at transmission/motor mount etc. The injectors all tested fine as far as noid light pulse. I did clean the egr as well and have tried two different ones. I also did a smoke test and didn't didnt see any leaks. Car is pulling 19hg at idle. I swapped out the iacv and cleaned as well. I feel like the only thing left is the wiring harness or ecu but like I have heard before the ecu rarely fails in this way.

I must re-iterate I appreciate all your help especially for a new member on this board.

 

Okay here is a silly update. I pulled the fuel pump out on a hunch to find a bunch of stuff in the bowl of the bottom of the tank where the screen(filter) sits. Looks like sand/rust mix. This must be why fuel pressure is steady at idle then when you hit the gas is starts to miss since it sucks all that to the screen causing it to collapse as the fpr raises pressure Still weird that fuel pressure read within spec but on the lower end.

There was also corroded butt connectors to the fuel pump plug that someone did for repair or something. The level sensor rod was also bent oddly and there is maybe a 1/2 gallon of fuel in the tank while the gauge reads near 1/4. I feel like I should have known better but usually a fuel pressure test shows how a fuel pump is operating, hopefully this clears up the missing now. As for bent valves, and zero cyl 2 compression, must have been associated with constant strain on the engine and missing due to the stretched/broken timing belt and considering the customer would be running the tank down before she knew it was almost empty at 1/4. I will update as soon as I clean the tank and get some fuel in there.

 

AND...... no change. Seemed better until I drove 100ft and it starting missing bad, p1399, p300.

Must be ecu.

 

Wow. Sucks to hear. Good luck in solving this frustrating problem.

 

Jgtecnik you have answered all my questions! I've been going through the same thing for the past month, p0300 p1399 p0301 p0302 p0303 I changed distributor wires plugs valve adjustment and swapped injectors nothing! I talk to a mechanic and he told me if it's not the injectors it's the injector sending unit(which is in the ecu) and you have to change the ecu. Anyway thank for posting all of your trials and tribulations because I was getting ready set the car on fire!

Now as far as the computer goes can I get one from the junkyard \ebay that is the same model, motor type, year or do you need to get one and get it programed?

 

What is your spark advance value you are getting from scanner

 

My car has same problem and it seems i have figured out the problem. Have a look at timing check I did

https://honda-tech.com/forums/showth...4#post49426434

 

Did changing ECU worked for you?