Accord 97 EX-R OBD1 F22B1 AT bone stock (Brazil export from the time I reckon).
1 connector dizzy, 9 pins.

tl;dr: misfire on cyl1 when engine is hot, replaced all dizzy parts (except igniter), cleaned injectors and intake parts, new plugs and wires, new ECT, cleaned EGR system.

Hello, Honda-Tech!
I've been lurking for a few years now, but recently I acquired an old Honda myself :D.

When I bought it, it didn't have a CEL, so I couldn't diagnose anything. I fixed the CEL and some codes poped up right on. The most constant were CKP sensor, ECT and VSS.
Fixed VSS (replaced it) and ECT (connector was destroyed and unplugged, sensor was OEM still).

Then I started to tackle the CKP code.
Started with new plugs and wires. Also cleaned injectors, IACV and FITV for good measure. Fixed a few vacuum leaks here and there. Car purred like a kitten since then. But recently it started to misfire on cylinder one and the CKP light popped-up again.

Replaced cap, rotor and coil (mine is internal coil). Couldn't find an igniter for sale so I have to wait a few weeks for it to arrive. Dunno why but exports were sold with an Odyssey dizzy (as far as I could notice). Also cleaned the EGR valve and EGR ports (the manifold was all the way blocked with carbon deposits).
Car still misfires on cylinder 1 after engine is warmed up to full operating temperature. Removing the nº1 wire and/or injector does nothing on the engine.

But then, recently, I disconnected the ECT to see how the engine would behave. Sure enough, car ran smooth, all 4 cylinders fire, if I remove the #1 cyl injector or wire it oscillates a bit. Started to scratch my head because I have spark, fuel and air.

Another weird symptom: if I start it up with ECT connected and engine cold, it cranks and starts like a charm. I let it warm up to full operating temperature without touching the gas pedal or changing the selector position and the engine still runs real smooth. Then, when I put it in R or D4 and start accelerating, I feel a sudden change in the engine behaviour, like the car went on limp mode but much worse. Then it idles like poop and sputters in acceleration before 2k rpm. Before I changed the cap, rotor and coil a CEL would pop with a code 4 if I revved it up too high (like 4k rpm). After I changed the dizzy parts, no code 4 would show up upon high acceleration.
Also, when I turn the car off with hot engine and try to start it again, I have to crank it for a few seconds (like 10 or so). If the engine is cold, I can start it up pretty easily.

Currently I am driving with ECT disconnected so I can go to and from my gf's home, but it's idling pretty high (1,5k rpm) because the ECU can not determine the real engine temperature.

Any thoughts?

Thank you in advance!

 

Anyone? 🧐

 

Hi, it sounds familiar to me.
In my case, it was two bent valves (slightly but visually noticeable). That make loss compression and misfire when hot.
Hope it helps.

'C

 

Thanks for your insight, Contralto!

I'm planning on checking the valves clearance as soon as I get a decent feeler gauge set. It might lead me somewhere.

Today I replaced the MAP sensor and the engine started easier, all 4 cylinders fire correctly but the idle is too low now. I've got no Fast Idle either with the new map sensor.

 

Did you replace the map sensor or the map sensor and the throttle body? Since you mention fast idle, makes me think you swapped the whole throttle body.

Either way, did you test the ECT sensor to make sure it's not bad? Do a resistance check and see if the resistance matches the motor's temperature or ambient temperature.

 

No, I replaced the sensor above the TB. I tested the old one and it was reading 3.5 V at II position (key position). The TB was removed and cleaned but not replaced.

I haven't tested the ECT yet, I'm trying to figure out a way to test it without burning my arms and hands lol. But as I stated, it's a new MTE-Thomson sensor (OEM ones are really hard to find here) and a new connector. The old one was destroyed and exposed.
I'll try testing the ECT and return with the readings. Thanks a lot!

 

Forgot to mention: after the MAP sensor replacement, the exhaust is smelling gas A LOT at idle. My eyes were sore from being in the garage. This and the low idle.

 

I did mostly you did: dizzy, cap, crank sensor, ect, iat, iacv, fuel pump and line, spark and plugs, timing, etc.
I have suspected the compression, but no visual sign (no oil-water mix, no overheating, no oil burnt).
Then I decided just to clean the cylinder head. Then I found it the bent two valves. I'll post the pictures.

Cheers,
'C

 

Pics are always welcome! Valves are hard to diagnose unless you disassemble everything. I use the car a lot and don’t have much space so I can’t do it.

My friend said to disconnect the O2 sensor and see how the car reacts because of the fuel smell from the exhaust. I’ll keep updating the thread anyhow.

Cheers!

 

Hello, everyone!

So, I've been short on money and couldn't mess with the car for a while.
I just came back from an Accord specialist and he had a OBD I scanner, said the rich mixture is a faulty O² sensor. He also cleaned the intake manifold which was full on gunk (that's why some cylinders weren't firing correctly).

I'm just leaving the solution for anyone having the same issue as mine :D.

Thank you for all the answers!