lsjon

So ive owned multiple civic's and never have had to deal with egr valves.

Vehicle i currently have is a 93 vtec prelude model with a f20b(blue top dohc vtec) installed.

The previous owner did the swap, and at that time installed a egr block off plate.

Engine management im running is a simple p13 ecu, which of course codes for no egr.

Issue im running into is hesitation at 3k-4k range. Which from what i hear is a common egr problem range.

Question is does this sound like my main problem is i need to have a chipped p28 to compensate for not having a egr any longer, or does this sound like theirs something flawed in the capping off process, such as ports, vacume, whatever the case. Though i believe the ports only come into effect when your recirculating the air back in after going through the egr valve.

Ive tried to trouble shoot this as best as possible, but their hesitation area is driving me nuts so im desperate for ideas.

The car at times basicaly feels like turbo lag, you feel it revving up, but theirs a hesitation spot for the power to kick in.

TurboBB2

Your problem might be that chipped p13.. those really are not the best ecu's to chip at all. im running a p28 on neptune no issues. sounds like its putting your car into limp mode, wont rev past 3-4k, prob dumping a lot of fuel. no vtec

lsjon

It's a non chipped p13, im having issues before the check engine light comes on though, so im not sure if that's because the ecu is searching for egr data and throwing stuff off before the light comes on or what. I believe limp mode is only when the light comes on but im not 100% sure. The car will rev past 3-4k 97% of time, theirs jsut some points of giving the car throttle that it will stay in that area, so i have to let off the gas or shift gears to get over that power hump delay. Car will generally hit vtec as well even when light is on. Not sure if limp mode is supposed to negate vtec or not.

TurboBB2

Well in that case, P13 isn't the correct ecu for the motor. Granted, the dohc f20b uses same block and very similiar to h22 s, i don't think they are similar enough to just hook up the ecu and have it run properly but it will run. But that egr may definately may be the issue on a non-chipped and tuned ecu, if it isnt chipped and tuned its prob still looking for the egr and probably throwing a code which still leads to an ecu issue.

In any case even if you weren't having an issue i would get a p28 and have it tuned or basemap at least.

Im not entirely certain but i believe there are obd1 and obd2 versions of the f20b.. that could be causing an issue also. try to find out what year the swap came out of, 95 and older or 96 and up because thats where obd1 and obd2 switched. Im pretty newbish when it comes to F-series.. but check into that.

lsjon

I think your thinking of a different motor. The motor i have is a DOHC vtec f20b, which wasnt a stateside motor. It's orginally a obd2 motor, so i had to use all the original obd1 h22a vtec stuff that came with the vtec model prelude to switch it to obd1. But yeah though people say the p13 runs it im aware it's not gonna run it 100%. I'm in the works to get a chipped p28.

TurboBB2

Yes im thinking of the DOHC version which is why i mentioned obd2... but i wasn't too sure i dont know too much about f-series but ive heard of obd2 and obd1 f20's so figured id mention it. I guess the odb1's are the single cams?

Thats good, let me know how it runs after the tune.

92civlude

Since the Prelude is already wired for EGR. Have you considered installing an EGR system?

blue5thgenbb

Is this an intermittent issue? When does this tend to happen? I have a similar, potentially the same, issue with my car. I have a 2001 base with h/i/e and a gutted vibrant cat. Anyhow, I dont think a defective egr, or lack there of, would cause this issue. My egr is still intact and operative. In my situation I think this may arise from an unhappy o2 sensor with a spark plug defouler on it. I do not throw any mil codes though. Perhaps your issue could be related.