HondaPaul

223k on original engine, head gasket blew, found low mileage motor cheaper than doing head gasket. Figured it would be a better investment.

Here is my issue:

Got new engine in, fired up right away with a slight rough idle. Checked for vacuum leaks none found. Tested IAC according to manual and it tested good. When depressing the accelerator slightly the engine would die immediately. After a few times i got the car to rev to 3k, but while holding the gas pedal steady the car will hold at 3k RPM for a second and then drop to 500 RPM for a second and then back up to 3k RPM and back down. If i let go of the pedal the engine will idle down and die. The car will fire right back up with the slightly rough idle but has the same surging problem. No surging at idle though.

Old engine ran fine with no issues before Head gasket went out. Intake manifold, injectors, ex manifold, o2 sensors Crank position sensor and distributor all from old engine. new timing belt on replacement engine.

Had a DTC P0505 Idle Control System Malfunction. Not sure if that was an old code or new to this problem. I cleared the code, have had a few starts to temp and the code hasn't returned. No other DTC's though.

I'm new to Honda's. I've been wrenching on Volkswagens for over 15 years. Going through other posts on your board trying to find an answer for my problem I've noticed the Honda community is a tight group with people willing to help out. Thanks in advance for any help you guys/gals can give. Even though I'm a noob.

KINGFLIP

give the motor about 15-30 minutes to warm up, somtimes you jut need to leave the car idle to let the ECU re-configure itself. that's my only guess

HondaPaul

kingflip, thanks for the reply.

I was thinking the same thing and have done a few cold starts letting it come to temp each time and idle for a while with no improvement in response. The reaction I'm getting is different though.

Now I'm thinking TPS, but not certain because of no CEL's. On my generic OBD reader i'm not getting any change in the % reading with pushing the gas pedal. I've yet to put a volt meter on it because of its location.

tim73

Did you get all the air bled out of the engine, especially the throttle body?

HondaPaul

I bled the air from the bleeder screw on the upper radiator hoes at the head. How do u bleed it at the TB?

tim73

Just have to make sure it is all bled out. Use the bleeder screws...also as you fill it, squeeze the radiator hoses, and that should help force bubbles out the top of the radiator. Run it a while, then check the radiator. Add as needed

HondaPaul

I made sure all the air was out of the system. I'm getting a fuel psi tester just to make sure it's not something with the fuel pump.

Any other thoughts?

Lost Again

Yea, be sure you have the map and tps connectors on the correct sensor - it happens more than you think....what are the wire colors going into the tps?

What year is this - 96~02 ?

HondaPaul

Cars not with me but I'll check the TPS sensor and MAP sensor plugs. Wouldn't that that throw a CEL? Car is 2002 w/ VTEC auto trans

v4lu3s

is the cam timing correct? distirbutor in good shape internally?

HondaPaul

Cam timing is spot on. I'm guessing dist. Is good, worked on old engine. Wouldn't bad dizzy be a run or no run scenario?

Lost Again

Had a chance to look at the car yet?

HondaPaul

That was it. TPS and MAP sensor plugs were swapped. Runs like a champ now. Thanks a million

Lost Again

Glad you got it

Feels better now doesn't it

EDIT: I would go ahead and clear all codes and do the proper "idle re-learn" procedure. From there - enjoy the ride.

HondaPaul

Feels a lot better. I was ready to change out the TPS before your post. I wasn't getting any flucuation in the reading on my scanner when pressing the gas pedal. Makes sense when the wrong connector is hooked up. I did clear the codes and will do a proper idle relearn procedure. Thanks again.

Lost Again

My pleasure.....your description is the classic sign of this - and as I said this happens more than you think. End of the day - car is running and you are happy