1998 Honda CRV RD1, 5-speed manual - B20 Engine - odd misfire in 2nd gear

Question

Hi Scotty.

I only discovered your YouTube channel last week, and I have been binge-watching ever since! I especially love all your tips on simple preventative maintenance, to help avoid major bills at the Stealers... Thanks!

I have bought an old RD1 1998 Honda CRV B20 2.0lt petrol engine, 5-speed manual transmission with 100,000 miles on the clock. I have had this mileage verified to be true and the vehicle in general is in excellent condition. The car has a service history with Honda (stamped in the service book) at the recommended intervals / mileage until it had 40,000 miles on the clock. The manual transmission / clutch shifts smoothly and feels almost new and in general the car drives very well; better than some new cars I have driven... The engine oil is clean, new filter, coolant is clean, idles smoothly, runs at normal temperature, fans work, check engine light comes on and goes off at startup as it should.

The issue is a misfire/hesitation from the engine most pronounced when it is cold, (70 degrees ambient temperature). This occurs mainly in 2^nd gear, only between 2000 to 2600 rpm, after which it accelerates smoothly. This misfire is not nearly as bad when accelerating in 1^st gear when the engine is cold, nor is it nearly as bad in 3^rd gear or 4^th gear when cold. Once the engine has reached operating temperate in a couple of minutes of driving, the misfire / hesitation almost disappears, but can still be felt as a faint flat spot at the 2000 to 2600 RPM rev range, again mostly in 2^nd gear, when the engine is under load, like climbing a hill.

It might be unrelated, but when accelerating hard (with warm engine) in 2^nd gear, it feels like there is the same flat-ish spot but also slight vibration through the drive train, also felt through the steering wheel, in the rev range of 2000 to about 3000 RPM. This vibration is not apparent when accelerating more gently in 2nd gear through those revs when warm. There is not such a noticeable vibration felt when accelerating hard in other gears throughout the same rev range when warm.

Mechanic I took it to has said that it might be a hard one to diagnose, because its only so pronounced when cold for the first few minutes of driving.

Do you have any advice on where I should start looking please?

I have not tried any trouble-shooting yet as I'm hoping to start with the most likely culprits based on advice.

Thanks

scottykilmer · Accepted Answer

Well the first thing I would do would be a wet and dry compression test of the engine removing the spark plugs and testing the compression dry and then wet to see if the engine is worn out internally on that cylinder. If not that it could be a bad ignition coil you could swap it with another one and if it goes away that's the problem. If not that it could be a bad fuel injector on number two would you could also swap with one of the other ones to see if the mess moves

joe79muller · Answer

Thanks Scotty.

After adjusting the valve lash to spec twice, (twice cause I messed it up the first time loosening them far too much), I tested the car. While it did seem to run a little better, the slight hesitation to the engine when between 2000 and 3000 RPM is still there, most pronounced when cold and in 2nd gear.

I ordered an Innova 3612 Compression Tester and carried hot-dry compression test, cold-dry compression tests and cold-wet compression tests. (I read number good reviews on this tester - link below:)

https://www.amazon.com/dp/B000EVU89I?psc=1&ref=ppx_yo2ov_dt_b_product_details

The results:

Hot-Dry Compressions:

Cyl 1: 185 PSI, Cyl 2: 180 PSI, Cyl 3: 175 PSI, Cyl 4: 185 PSI = largest variation = 6%

Cold-Dry Compressions:

Cyl 1: 180 PSI, Cyl 2: 175 PSI, Cyl 3: 170 PSI, Cyl 4: 180 PSI = largest variation = 6%

Cold-Wet Compressions:

Cyl 1: 225 PSI, Cyl 2: 215 PSI, Cyl 3: 210 PSI, Cyl 4: 220 PSI -> largest variation = 7%

So Cyl 3 is slightly down on compression and Cyl 1 & Cyl 4 have the highest compression, but they are not far off each other.

Do you with a max 7% variation between results, this is a probable cause for the engine hesitation problem ?

I have also tried to fix the hesitation by replacing the following parts with only new genuine Honda parts or genuine new OEM parts:

New NGK spark plugs
New Honda fuel filter
New air filter
New Honda spark plug leads
New Honda distributor cap
New Honda Rotor
New Honda Ignition Coil (This 1997 B20B engine has one coil inside the distributor, not individual coils on each plug)
New Honda Ignitor

I also ran a bottle of ATS carbon fuel cleaner through half a tank of gas to see if that would improve things and while I think the car is running a little better, that hesitation between 2000 and 3000RPM (especially in 2nd gear) is still there, most pronounced when the engine is cold.

Any ideas where I should look next please?

How can I check if it is a fuel injector? Should I buy one new fuel injector and replace the ones on the engine one-by-one with it, to see if I can find a bad injector?

Could it be something else electrical? Vacuum? O2 Sensor?

Any help would be most appreciated!

Thanks

Joe