b20b/vtec problem!!

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dramathaized

New Member
hi peoples,

This is my 1st thread so bare with me. My friend has a 99-00 honda civic dx hatchback. He recently swapped a b18c1 gsr motor in to the car. The bottom block ended up making noise and come to find out that it was bad. So, he decided to go b20b vtec with the gsr head, tranny, and p72 ecu. Ok, to the point. After completing the swap, he can drive the car but when he steps on the clutch WITHOUT giving it gas, the car will die out. When he starts the car, the idle drops really low and then dies out. Any ideas on how to fix the car from dying out when he steps on the clutch would be really great!!! PLEASE HELP :confused:!!! Thanks.
 
i would look at tha tranny and recheck everythign tranny and clutch related if tha car will idle and revv fine but it will only die when u step on the clutch it has to be something with tranny or clutch. for istance if u were to stop the car in 1st gear it will die so i would recheck everythign in that area
 
that was already checked, i believe. The guy who installed the motor was a honda mechanic. When he finally finished the swap, he couldnt figure out why it was doing what it was. Is there anyone out there with the exact or close to same problem? I am stuck on this myself. Thanks.
 
so the car idles as long as you don't push the clutch??? or is doesn't idle at all?
if it's not idling at all then check the IAC, maybe it's not working or is wired incorrectly, here's a link to a writeup about 3 wire and 2 wire IAC for some of the obd2 vehicles.
https://hondaswap.com/swap-articles/obd2-obd1-iacv-fix-3-wire-2-wire-47169/

if it idles fine unless you press the clutch then it is probably a problem with the wiring in the vehicle, there are 2 switches on the clutch pedal itself, one is the neutral safety (2 wire) where if this was bad the car wouldn't start at all, the other switch has more than 2 wires and is used by the ecu and the cruise control system.
Another thing to look at is the throw out bearing, if the throw out bearing is bad then it will cause alot of drag when you try to push said clutch, since the bearing is what does the pushing against the pressure plate release fingers/forks.
Just post back if it idles normally or if it has never idled at all, even if in neutral.
 
it idles fine when you're driving. if the car is in neutral and it idles.. the idle slowly goes down until it dies out. If your driving, lets say, on the the freeway, and you need to shift gears, the car will die out if you step on the clutch WITHOUT giving it gas. So, as long as you give it gas when planning to step on the clutch, then the car wont die out. any pinpoint advice you could point me in would be great. i have to check to see if the guy changed out the throw out bearing on the car or not. and i will also check the IAC as you suggested and get back to you.
 
there is no such thing as idling while driving, idle is the car in neutral or park running with no load and no throttle.
try starting the car, don't touch the throttle, just push the clutch in and turn the key, make sure the car is in neutral, and then let the clutch out. see how long it runs for. if the car won;t even start without pressing the throttle, then it may even be fuel related, like a bad fuel pressure regulator.
If you can get the car to run in neutral like I said above, then do a fuel pressure test, it should be between 40 and 50 psi at idle. if it's lower than that then you have either a bad fuel pressure regulator, a clogged filter or a bad pump.
Another thing that may be alittle out of the ordinary is the o2 sensor, SOME cars will start and then die immediately if the o2 sensor heater wires are backwards, but its rare.
 
hi peoples,

This is my 1st thread so bare with me. My friend has a 99-00 honda civic dx hatchback. He recently swapped a b18c1 gsr motor in to the car. The bottom block ended up making noise and come to find out that it was bad. So, he decided to go b20b vtec with the gsr head, tranny, and p72 ecu. Ok, to the point. After completing the swap, he can drive the car but when he steps on the clutch WITHOUT giving it gas, the car will die out. When he starts the car, the idle drops really low and then dies out. Any ideas on how to fix the car from dying out when he steps on the clutch would be really great!!! PLEASE HELP :confused:!!! Thanks.

its could be lag of fuel or too rich fuel on idle
if u can get an afr meter its could safe for your motor and find out your problem
 
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