Alright, i have a turbo gsr swapped del sol, everything built and balanced properly, running perfect for over a year. Just recently i go to start up my car, starts right up, and after about 30 seconds or if i start driving all hell breaks loose.

The exhaust note changes like vtec has kicked on, the afr goes to 10.1 to 12.6, and the idle lopes like it has a crazy cam in it.

One it reaches operating temp, exhaust note changes, afr goes right back to normal and all is perfect. No problems.

-ect sensor replaced
-new main relay, my old one got moisture in it (fixed)

Any help would be appreciated

 

The first thing I'm going to ask you about is your MAP. You're using what for engine management?

 

Sorry, i should have put that on here, tuned on crome pro from a chipped and socketed p06 ecu

 

It's not abnormal for a cold engine to run rich.

CEL codes?

Last tune up?

 

Yeah but its at the point where it barely idles. And i do all filters and plugs every year, so i had just done them a month ago.

 

It sounds like a tuning issue. Who tuned this? Innovative?

 

Yeah innovative did, but it was tuned and ran for over a year with no problems

 

You might want to stop saying that.

 

Could it be possible that the iacv would be causing this? I know they screw with idle, but do they adjust fuel as well?

 

How are you jumping to the IACV?

 

Why don't you touch base with the tuner to make sure the tune isn't responsible. It could be O2 feedback gone haywire. Maybe the O2 sensor has gone bad.

 

I jumped to the iacv because i know they cause idle loping problems. And its obd1, i only have a wideband o2 for monitoring. Ill see if i can call and see if he needs to re do the startup fuel maps or if that could be the culprit

 

I would check with the tuner . Most tuning shops will either re-tune or maybe check it out for a discounted price, because you had it tuned there and came back with the same car/setup.

 

Alright, made an appointment with my tuner, im the meantime i decided to do some tests. Tried to get more air out of my coolant, tested the throttle position sensor which was fine. And i checked the map sensor (2.5 bar motorola) i checked the voltage between the green/white and red/yellow wire and got 5 volts which is normal, however when i tested the green/white to the solid white wire, i only got 1.37 volts. Not sure if that means its shot or if it has a lower voltage because its an aftermarket one. Anyone familiar with those sensors?

 

Map sensor output voltage directly relates to manifold pressure. since higher pressure sensors read more pressure for the same 0-5v scale as OEM that means at idle output voltage will be lower.

 

Damn, there goes that idea. Is it really possible for a tune to lose its cold start map just like that?

 

Problem solved guys. If anyone has the same problem and has hit a wall, take off your vtec solenoid and check the gasket. Mine was new but it was a little stretched, im assuming just enough so oil would bypass the solenoid completely. And when the engine heats up, it expands and seals it tight. My only guess as to what it was.

 

How does a VTEC solenoid cause a car to run rich? Asking because in the years I've owned these cars I've never had this issue.

 

If enough oil was being bypassed to lock the rockers and engage vtec then technically it should have been running lean.

 

Wouldnt it adjust the iacv due to the idle loping so much to add more fuel? I guess i didnt think about that. It should have ran lean. I just cleaned up the gasket and slapped some hondabond on it and it was good to go

 

What does the VTEC solenoid have to do with the IACV?

 

Theyre indirectly related because the larger cam lobes would change the idle, and the iacv would have to adjust right?

 

I'm not quizzing you. You asking me or telling me?
What larger cam? You know you have two of them?

 

I was unsure, i figured you knew. How else would it have solved my issue?

 

Well, I have a problem with your fix because I have yet to see someone solve an IACV issue by working on the VTEC solenoid. I think it was absolute coincidence.