Hey guys, I have a 1994 Honda Accord Lx with a JDM F22B2 Engine (replaced 3k miles ago). It has a horrible idle surge issue that won't seem to go away. I have been throwing parts and trying to diagnose for about 3 months now, and am at a complete loss of ideas as to what the culprit is

The problem occurs every time when cold cranking and throw a CEL code 14. Once it's warmed up I will shut off and crank the motor back up. The issue will usually stop for about 10-100 miles, then it will come back and act like it’s going in to limp mode all of a sudden. I will lose throttle response every 5 seconds off and on. It will then throw a code 14. What gets me is that I replaced the IACV twice and the pig tail once, but it still is throwing the same code 14...

I have bled the coolant numerous times, thinking it was just air in the system but I notice that air keeps coming into the system after warmed up and cooling fans come on. Below is a list of parts I have replaced or cleaned. Also, there is no coolant/oil mixture

Please help me fix this idle issue, as this is my only vehicle at the moment and have put too much money into it to give up.

Replaced (NEW):
* OEM IACV
* OEM FIV
* OEM MAP Sensor
* OEM Radiator/Thermostat/Water pump
* OEM Timing belt (installed by Honda, Timing is correct)
* OE replacement Dizzy cap
* NGK Spark Plugs & Wires
* NGK 02 Sensor
* OE Replacement EGR VALVE

Cleaned/Inspected:
* TB and the port going to IACV
* EGR Ports
* No Vacuum leaks
Compression Test:
Cyl. 1- 180 psi
Cyl. 2- 182 psi
Cyl. 3- 180 psi
Cyl. 4- 185 psi

 

Code 14 is a fault in IACV circuit. That can mean faulty IACV, connector, wiring, or ECM.

Since problem is intermittent and you have replaced IACV, look for a fault in the wiring, connectors, or ECM.

Fault tracing requires use of a VOM to measure resistance of the IACV solenoid coil, a few ohms. First disconnect from engine harness and measure resistance of the new IACV, reconnect and measure resistance again at the ECM/Harness connector under dash for the IACV drive wire. If same resistance, the ECM may be at fault.

Intermittent nature complicates the investigation, as correct resistance measurements may occur if fault is not present.

If this fault was not present before the engine replacement, look for damaged wiring possibly from engine removal/installation.

good luck

 

Thanks TexasHonda, I will post results today.

 

Look in the DIY section for a thread about setting the "BASE idle". Go through that.

Honda idle-control can be finicky, and if you outsmart yourself by trying to adjust your idle-rpm that will probably result in the ECU fighting against your "new" adjustment and it can surge like that.

 

Had to go gout of town and didn't get a chance to work on the car today. Will post results next week.

 

Sorry for the delay guy's. Just to clarify, I double checked every cyl. and made sure each one was at TDC. I'm assuming that my timing is off by a tooth or so... I am going to check the timing either today or tomorrow and post my results.
F22B2 Leakdown Test:
Cyl. #1: 19%
Cyl. #2: 80%
Cyl. #3: 35%
Cyl. #4: 58%

 

Leak down test results are bad, you should be under 20% on all. I'd repeat test making sure tester is tight to plug hole. If fails again need root cause - head gasket, rings, etc.

 

One thing about a leakdown test; you can often hear where it's leaking to.

Leaking into crankcase = rings
Leaking into coolant = headgasket
Leaking into exhaust manifold = valve not closed
etc...

 

draser- I did a leak down test twice and the numbers were about the same both times.

JimBlacke-Air was coming out of the Intake Manifold, which leads me to belive my timing belt is possibly off a tooth...

 

What position was the engine in when you did the leak-down test?

The best would be TDC on the compression stroke, meaning you rotate it to a new position for each cylinder before you test it. At TDC you have to be very careful to lock the crankshaft so the compressed air doesn't cause the engine to suddenly spin.

Otherwise, you have to think about whether the engine is rotated into a position where the intake valve is SUPPOSED to be open. There's some overlap at the bottom of the stroke.

If the engine WAS at TDC/compression, then a few teeth won't make any difference. First you should check your valve-lash adjustment & hope that's why the intake valve was open. Otherwise I hate to say your valves are bent.