the car is a 94 gsr. Intake manifold is a Skunk2 so im not hearing the butterflys open. Exhasut is a BC:S2 so it's noticible when vtec hits. im not beating on the engine i backed off quickly when i heard this happen.

new:T-stat,ECT sensor and Chipped p30 within last month. no cels

this makes no sense at all

 

Something I was thinking about from your other thread -- some chipped ECUs force open loop I believe. This may mean your ECU is always calling the same maps and the same settings no matter the sensor readings. So you'll get VTEC on a cold engine, and no warmup maps etc. Not sure what the deal is with your temp. readings though.

Did you mention that you tried swapping ECUs with a virgin ECU?

 

This crossed my mind, but i don't see why they would have it be in open loop all the time as it get **** for gas millage and other negative symptoms(ran open loop once before on my old p72 when i was waiting for my o2 sensor). on my other thred i had that feeling to but i guess that's possible. This never happened with my old chipped p28 infact it took ages to hit vtec(ecu ended up frying). don't want to go back to a virgin p72 either tho as:I,H,E,IM,TB,cams,increased comp.

 

Mine did it too when I first chipped it, there was an option to disable vtec temp enable that was selected by default. Not sure what damage if any it would cause.

 

I have no real way of telling when the engine is warm other than to assume after 5 mins of driving. but till then i just go up to 3k rpms 4k at the most my chipped p28 never had this but it ended up with issues.

when in open loop the primary o2 is dissabled no ? along with one or 2 other important ones

 

in open loop the engine runs solely off the maps

 

Maps meaning what ever's on the chip right ? thx for the help guys wasn't sure if an ecu could run constant open loop.

 

yes. if the part throttle maps arent tuned very well that would account for your bad gas mileage.

 

No offense but this car seems like a whole pile of problems. You've got some serious tune-up work to do. I'd:

- check ignition and cam timing
- check valve lash
- check compression
- test all the sensors
- test fuel pressure
- test the distributor and plug wires and check spark
- test vacuum
- visually inspect all the visible wiring to the engine and continuity test suspected connections

You're going to need a systematic approach if you want to solve these problems.

Edit: and do it all on an ECU you KNOW works -- like a stock ECU correct for the year of your engine.

 

I've done the basics(cam timing,comp, fuel pressue,vac) and that everything is connected properly. last thing i can "DIY" is lash. then im going to have to resort to a garage for the testing of sensors,distributer,ign timing

 

I have an ecu that does the same. It's a hacked up p28 that was sold as a p72. Was pretty upset. Doesn't seem to have a limiter either and the vtec pops at 5500.

Terrible idea to use vtec when cold though. That's how leaks and blown parts happen.

 

It's possible to tune on open loop but AFAIK closed loop is prefred/easier. It's a temp ECU till I can get back to my tuner and pick up a new one(w/ new basemap).

 

It's actually preferable (actually pretty much necessary) to tune on open loop. And if you get a good custom tune, there is no need for closed loop! Open loop is kind of a "Band-Aid" that gives the ECU flexibility when conditions are weird, or for when a single basemap (the stock tune) is used on a hundred thousand cars all over the world.

 

you only tune in open loop.