ok i just recently got my car started and idling it idles at 2k rpm and surging between 1.8k rpm and 2k rpm. not to worried about that simple fix with the pcv and the hose to the pcv nipple on the manifold but anyways the main issue i have is it bogs when i give it gas like it would idle at 2k rpm then when i press the gas pedal down the motor would go really quiet and the rpm drops from 2k rpm to 300 rpm and stays there until i decide to let off the gas pedal then it returns to where it was idling. i have cel on got the codes by jumping the blue connector with my paper clip got codes 6-ect, 10-iat, and 22 vtec pressure switch. as i recalled my boy had the same iat code on his hatch and his drives just fine with no issue so i high highly doubt that's what causing the bogging issue but i can be wrong lol. what do you guys think the main problem is?

i'm running a step down harness with a chipped p28 in my 97 civic coupe

 

is timing mechanical on ? vac leaks ?

 

yea everything is good it kept triggering a check engine light for iacv but fixed it but it seem to bog out after it get triggered i got the chip re done and it cleared it but i forgot about the iacv whichi now fixed but i can't get the ecu to stop bogging out it got it to 3500 rpm but i had to be on the throttle slowly and gradually

 

whats are the specs on the engine? what computer and tuning program are you running? has it ever ran normal since the upgrades?

 

Check your TPS voltage.

 

already did before when i had bunch of cel codes i checked it and had a open ground so i fixed it checked it again it reads normal .5v-4.5v fully open as before it used to just read 4.9v regardless of the throttle position

 

Have it tuned a chipped ECU is not a tune

 

yes its going be tuned but tow bill to get it to get it tuned is going to be 2x the bill of getting it tuned in the first place not an ideal thing so i have to be able to drive the car to get it tuned..

 

it worked momentarily before so it can work again

 

as far as program i have no idea i had the basemap done at full throttle i have a built bottom end eagle rods with vitara pistons, stock head t3/t4 50 trim turbo 38mm waste gate. stock head running a p28 with a obd2a to obd1 step down harness. it ran normal about 4 times but one of the iacv wire was wired to a wrong spot and it was triggering a cel when you rev it. i got busy with other things during that week so i kinda forgotten about it. week after i went back had the chip re-done with the launch control disabled. when i plugged it in it worked great twice. but i reminded me of the iacv problem when the cel came on at 2.5k rpm so i fixed it and it no longer triggers a cel it idles normal 950rpm when its fully warmed up but if you just open the throttle it just cuts out and bogs but if you slowly and gradually go up the rpm it goes up to 4k rpm then it just misfires.

 

You've gone back and fourth between "I had these CELs" to "I fixed this, but then this one came up". At this minute (not in the past), what CELs are you throwing? If it isn't being thrown right now, it doesn't matter. This isn't a turbo problem, this is a "you did something wrong with the motor and now you need to fix it" problem.

 

You might have your ect and vtec plugs switched around. As for the iat code I don't think the p28 would recognize that sensor

 

I already checked that back when I had 5 codes as of right right now there's is no cel even when I rev it alittle bit the iacv is no longer triggering the cel like it did before when one of the wire was in a wrong spot fixed by putting that one wire to the correct spot so it no longer trigger the cel light like it did when you got to 2.5k rpm

 

I am having the same issue in my civic as well no check engine lights running a stock p28 ecu and it bogs down the same as yours. When in neutral or park however it will rev to redline it only bogs when it is placed under load. I replaced the primary o2 sensor, distributor, plugs, wires, and the TPS with no luck yet.