oki had this problem for awhile and cant seem to get it. the car runs smooth until vtec engages. it just starts bogging when vtec engages almost like something forgot to kick on. so fat i have changed the following and still no luck

-o2 sensor
-spark plugs and wires
-vtec wiring
-oil
-fuel filter
-throttle body with sensors
-intake manifold with all sensors
-step down harness for ecu
-ecu
-distruibutor
-cleaned out vtec solenoid
-triple checked my timing
-triple checked all my wiring


I am going crazy i just dunno what to do anymore. so please if anyone has any idea let me know cuz i dont anymorel...

integra obd2a with a gsr block si head itr manifold/tb itr cams obd2a-obd1 chipped p28


any help would be greatly appreciated!!!!

 

jeck to see if the vtec selinoid is working properly hook a fire to the pos of you battery and hook another wire to your vtec selinoid and while driving touch the 2 wires before you go for the ride touch the wires to ensure the selinoid is opening and closeing it will click when you apply 12 volts also what kinda fuel system you running whats fuel preasure and whats your oil preasure if you can check those

 

well i changed out the vtec solenoid. not the vtec body but the solenoid its self but ill double check and make sure it clicks with power. as far as fuel system its all stock and i dont have a fuel pressure gauge. but everything on it is stock. now oil pressure is what i need to check i went to the local autozone and oriellys but they didnt have any so ill be going to this store that might have it here in a bit. because im thinking that might be the problem

thanks for the advice and any other help would be greatly appreciated!!

 

yeah if you don't have the oil pressure= no vtec but all the bearings are stock?

 

yes bearings are stock. checked my compression i got 210 all across. checked my oil pressure and it was around 40 at idle and went up to about 70-80 at around 3k-35k.
also checked for oil pressure at the head when vtec engaged and it was at 70 psi. so oil pressure is good where it needs to be. also vtec solenoid it working too because when i had it engaged to check oil pressure the gauge didnt stutter or anything. so im even more confused now since i figured this had to be it!!

guys any help would be greatly appreciated!!!

 

Jeeze man that is really something it seems like you checked everyting

 

i would check the distributor. If you have a buddy that you can swap real quick.....i think its the dizzy. Give that a try.

 

I'm assuming your running a p28 chipped correct?
When you tried a new ecu did you try a new chip as well or did you put the old chip in the new ecu?

IF you retained the old chip I can almost promise you this is related to the base maps on the chip, I had this problem with my b16, ran fine under regular driving conditions but when I went WOT into vtec it would bog and fall on its face till like 7k+ rpm.

Try a new chip with new basemaps... btw when is your vtec set to crossover?

 

check if the chip is working and tap the chip and see if its lose

 

im having the same problem >=[ my vtec hit at 4500 on stock gsr ecu

 

low oil will cause the problem also.

 

Memnoch is right

 

thanks for the idea man but unfortunately i figured this was it also SO i put in a factory p28 and problem was the same. i took my ecu to have a new base map installed and we test drove it in one of their cars and it ran perfect. once i put it in my car it did the same thing. so i believe ecu is out of the question =(

 

tried this also not sure if i mentioned it above but i had a friends dizzy laying around so i slapped it on there but sadly the same problem remains.

 

this is very true and frustrating.

 

something i noticed today though. i unplugged my vtec solenoid so that i could drive it on the highway without the hesitation problem and as i was passing someone up right when i hit around 4k the motor hesitated. it wasn't as bad as when i had vtec working but enough that i noticed it. right around 42-43k it just hesitates and works its way through it. so i dont think the problem is vtec related. I think the main reason why this is hard to figure out is because it doesn't do it when parked and it doesn't do it in first gear. its just wierd and i dont get it.

i was considering maybe changing out my fuel pump? but im tired of spending money aimlessly without getting anywhere. if anyone has any more ideas please let me know.I appreciate everyone with their input and i hope someone has some more ideas to throw out there! thanks guys

 

true but ihave changed my oil and checked oil pressure at the block AND head so i dont think this is it.

 

so i guess you guys are out of ideas like me? =(

 

You need to check your fuel pressure. Your car may run fine at idle with the fuel pressure you have, but under a load or accelerating a higher volume of fuel is needed so the fuel may be getting restricted. This will cause your car to fall on its face until you return to idle or a lower rpm. Either something is restricting it at the suction tube or somewhere in the line. Make sure your injectors are clean. Connect a pressure gauge to the schrader valve and see what kind of pressure you get when you accelerate. Also make sure your air filter isn't super dirty!

 

did you figure out what the vtec problem was i have a similar issue? I'm thinking my throttle position sensor needs to be calibrated.

 

did you figure out what the vtec problem was i have a similar issue? I'm thinking my throttle position sensor needs to be calibrated.