dscarps

Hi everyone,

I'm having a very strange hard start & rough idle issue with my 2001 CRV. It seems to be caused by a lean start and idle immediately after it gets running. Here's a quick rundown of what I've done to eliminate as many problems as possible...

First off, it has a b16/b20b swapped engine, which has ran fine for about the last 55,000km (~40,000miles). I was running on a crome tuned p28, but before my tune I ran my factory ECU and it threw no codes for almost 10,000km (~6,000miles). I'm also running an AEM UEGO 4.9L installed 1000km ago. Emissions products are all installed and working, except for the rear 02 sensor (fouler) which is unplugged and not present (P0141).

A month ago, I had a bad idle problem. Opened my distributor to find it full of oil. I replaced and timed it properly, and it ran with no issues.

~A week ago, my fuel pump seized. I pulled it, bench tested it with 12v, nothing. So I replaced it and she started running fine again.

Three days later, I started getting a hard start which required 15-20 seconds of cranking & WOT to get it running. When it starts, I have to modulate the pedal and keep it above 2500rpm or else it dies out immediately. Even with throttle, it shows high 17:1 mixture and even maxes out the UEGO at Lean. Once the idle drops, I can drive with lost power and still getting high 15:1 low 16:1 under load/cruise, but seems to steady out at operating temperature. Checked for vacuum leaks, found an injector seal that was cracked and replaced it ($4 part, go Honda!) Still had a slight power loss but the idle and running seemed to straighten out, though it still idled on the lean side.

The next day, again hard start with lean idle. In an effort to straighten out any tune/ecu issues, I put the factory ECU & injectors back in. Started it, and wham it ran perfect. Mid 13:1 idle at cold, ran mid 14:1 at operating and under load/cruise, and mid 13:1 under heavy load. Perfect, I just had an CEL to diagnose. I found the P0141 code for the rear O2.

The day after, back to the same cold start issues and lean running.

Please help

dscarps

Also, I now have a MacTools scanner that I can pull up the datastream for all sensor readouts.

MikesRJ

Have you checked the fuel pressure? When was the last time you replaced the fuel filter?

dscarps

Thanks for the reply MikesRJ, and sorry for the delay... I've copy pasted this from the other thread for this issue. Check it out:

Fixes/Changes
I've changed my fuel filter, it was very clogged. And my injectors had been sitting around for a long time, so they fouled up on the engine side with a sticky resin.

I had my tune ecu and proper injectors hooked back up. Also had the injectors serviced and tested, making from 402-409cc, they're perfect. It started up and drove for 2 days perfectly. A little rich at 12:1 +/- .5 throughout the rpm range, so that's not the immediate issue.

Ongoing Random Issue
Today it was driving fine, had 1 random sputter when I got on it. Then continued on without a glitch for two more trips. Later in the evening after a spirited drive, I parked for 2 minutes: it would barely start after and had no fuel pressure when priming over and over. After about 6 attempts, it fired up and had 40psi on the fuel gauge. Though it was running very lean at idle 16:1 up to over 18:1, and when I tried to drive it started going full rich 10:1+ with power loss. After about 1/4 mile, it started driving like normal again without loss and good mixtures.

@DCFIVER - Fuel pressure like I said above is 40psi, and it spikes about +5psi when you blip the throttle.