We are having a problem with a h22a prelude motor that we just swapped into a 94 prelude with a h22a1.

The car will start up and idle, 100 percent stock!! Soon as the car warms up it doesnt want to idle, and its very hesitant. We got code 12, EGR, and code 43, Fuel supply system( Could be o2 sensor)

The codes only come on, after about 5 minutes of driving from a start up at any temperature. and go off after every shut down period, but are stored. I put 10$ of supreme in the tank, running with the plugs that were originally in the h22a1. We suspect they are pretty new, as no hot spots.

Anyone lead us to a possible answer to our problem?

 

For the code 12 you, assuming your EGR is working, you can take it off and spray some carb cleaner into the port to clean it out a bit. If that doesn't help you might want to clean out the whole EGR system in the intake manifold. Also check the vacuum lines to the EGR solenoid.

For code 43 you can check the vacuum lines to the fuel pressure regulator, and if they are fine, then possibly the regulator itself. Also check to make sure the pump is running well.

Try swapping over the EGR components and FPR from the previous engine to see if it helps any.

 

CEL 12 = EGR Valve
CEL 80 = EGR Ports
CEL 43 = O2 Sensor or sensor wiring.

 

But could these codes be causing the car not to idle? It has zero power and for some reason the rev limiter is 6200?

 

^
The ECU is running in 'limp mode' due to the CEL's.

and Kronn... Code 43 is 'Fuel Supply System', 'O2 sensor' is Code 1.

 

I'm aware of what the code translates to. But if you read the Helms, it's caused by the O2 sensor.

 

well last night we un plugged the 02 sensor , reset the comp and then went for a short drive and the only code it gave was o2 sensor so this means o2 sensor was the cause of the code 43 ? Also another thing we noticed witch seems to be a problem is that it has very weak spark in all 4 cylinders, when you pull the plugs out and crank it over with them grounded there is very little orange spark and no blue. We tested/changed the plug wires and plugs also checked the extrenal coil as per manual and all checks out.

Gonna check a few more things later

 

OK, so we are down to one problem.. hopefully. There are no CEL's and the car idles and runs fine up to a 6200 rpm rev limit and vtec does not engage. What could be causing this?

 

You are in flacid mode, errr limp mode.

 

why would it be in limp mode? there are no codes and the car is running great other then the fact. Actually we just got word from our friend you owns the car that it has ALWAYS been like that. so now what?

 

bad ECU?

 

I'm thinking bad ecu to... anyone else have any input?

 

Well problem turned out to be that the screen inside the vtec selonoid was clogged up. Cleaned it and it worked great.

 

OBD1 does NOT moniter flow. Just lift. A plugged EGR system will not cause any codes on this car. To diagnose code 12, With the car idling, ground the frequency solenoid valve at the right shock tower. To see if vacuum is applied to the EGR valve. If there is vacuum at the EGR valve, if vacuum is present, the frequency valve is OK. Also check the EGR vacuum hoses, They may have gotten crossed during the motor swap. But 9 times out of 10, the frequency valve is the culprit. A code 43 is harder to diag. But with a motor swap, Debris could have contaminated the fuel rail and partially plugged an injector. This has happened to me! I JUST THOUGHT OF THIS. disconnect the vacuum hose at the EGR valve when its running. The hoses may be crossed somewhere.