Alright ever since i swapped in my b16a into my hatch i havent had any vtec... Found out my knock sensor was broken. Mind you i was never throwing #23(knock sensor). Anyways...so we put in the knock sensor and its running alot smoother now. We went to go see if vtec would pop and everytime i get to 5500-5600k rpms it skips, like my exhaust backfires/pops on nothing happens. Also when i do that my rpm gauge jumps around and kinda waves around. No Vtec. NO CHECK ENGINE LIGHT!

So if ANYONE can help me it would be amazing.
PLZ and Thanks in adavance!

If you have any idea at all just post it and i will let you know if i have tried it!

 

maybe u never had a CEL cuz your CEL isnt working? or the bulb is burnt out?
but yeah sounds like ur car is in limp mode. did u reset the ECU after putti9ng the knock sensor in?
and VTEC goes through alot of variables before engaging so if its something as slight as engine temp or oil pressure, you wont throw a CEL and wont have VTEC

 

the check engine light isnt burnt out. We reset the ECU after putting the knock sensor in...

 

I would check the oil pan so see if it's dented, perhaps there isnt enough oil pressure. as far as your rpm's jumping check your dizzy maybe it has some type of oil contamination inside or so... Distributor doesn't affect vtec, but it does have to do with your rpm signal.

 

if you have a obd1 ecu it wont look for the knock sensor in the first place. that may be why there was no CEL before you fixed it. as for vtec it sounds like there is a timing or ignition problem causing the issue.

 

If its an obd1 motor why does it not run correctly with an obd1 ECU. Just doesnt make sense to me if the motor requires a knock sensor but then the ECU that makes the motor run doesnt look for it?

As far as the timing do you mean that i should take a timing gun to my motor and re-do that?

Ignition wise - plugs/wires? i bought both brand new. Anything other than that im not sure so if you could elaborate!

Thanks for the help so far guys.

Also im going to replace my fuel filter to see if that stops the skipping/popping thing when i get on it.

Keep the advice coming!

 

Any OBD1 B series VTEC ECU most definately looks for a knock sensor. That was misinformation.

I can tell you that VTEC needs these things to work:

-CTS reading warm
-Oil pressure reading in range
-VTEC hardware/software/wiring in working order
-MAP reading
-TPS above certain %
-VSS reading over certain speed (12mph, IIRC).
-RPM trigger


The plugs/wires/timing have no effect on it. Neither does mechanical fuel delivery. ECUs are dumber than you think.

What year is the hatch? What ECU are you using? If you're using a P72 GSR ECU, I might know the issue.

If your gauges are jumping around, you might have a grounding issue somewhere. Check all the ECU and chassis grounds.

 

dbl check if vtec is even hooked up if its ran to the ecu or not.. dx wire harness does not have vtec wires so you would have to pin it in..( it would throw a code though if the ecu was hooke up but not ran to the motor i think)

 

It would throw a code if VTEC wasn't properly hooked up. But I have no idea which ECU the OP is using.

 

Im using a stock PR3 ECU

 

Ive also hooked up the following ECU's: p28 w/ s300, JDM GSR(made it run terrible), Skunk2 chipped P28, P63..might be one more...but nothing makes it work and im just so f'n confused.

When i hooked up the JDM GSR Ecu the car sounded like it was running on 3 cylinders. It constantly would putt. I could barely get up to speed!

 

Cmon guys anything?

 

When u used the s300 did you hook up the laptop and check all the perameters and sensors to make sure everything was looking good? When u turn your key to the on position the check engine light should come on for just a minute which lets you know the system is working, check for that. Check everything on the s300 that was listed by b serious (dont think u need a vss reading though). WHats a pr3 out of? delly vtec95?

 

I will deff. have to try that!

 

PR3s are out of B16A DAs and EFs.

hmm...this is a mystery.

The fact that plugging in different ECUs makes it run differently to the point where it misfires or acts up is strange considering this is probably a close to stock engine. It really shouldn't do that.


What year is the B16A? Or atleast which chassis is it out of? Is it JDM?

 

The ECU says B16a DA6 written in black marker. Also i tried lunching it the other day just to see if it would spit/sputter and it did badly to. The only ECU out of the ones i tried that really made it run bad was the JDM GSR ecu, both the p28's made it run smooth but still no vtec.

I havent hooked up the computer to it yet still waiting on my buddy with the s300 to have some free time.

Does anyone think that this could be leading to a bad distributor? I mean my tach waves around when i get into higher RPM's(vtec range). Its a stock motor with the exceptions of a ITR intake mani. and AEM fuel rail.

 

wait a minute...

DA6es and EFs had resistor boxes for the injectors even on the B series, IIRC...someone correct me if I'm wrong.

What chassis is the engine from?

OBD1? OBD2?

What type of injectors do you have on this thing?

Where was VTEC set at on the P28s?

 

This may be a stupid question but is your speedo working? When my speedo sensor plug broke it stopped working which in turn made my v-tech stop working. This is on a obd1 b18c1. car is a 99 ex. IF it isnt working vtech probably wont work. The check engine light didnt always come on but in most cases it did. Just a quick thought.

GL on finding the source

 

it was already mentioned above in a post...and v-tech

 

Isnt pr3 obd0
U got a jumper 0bd1:0bd0?

 

Exactly my thoughts, so this must be a obdo jdm ecu. Check ur oil level too haha.

 

He told me it was an OBD1 motor... I can get you guys the head# like PR3-? if that helps? I dont have a jumper harness because i was told it was obd1, and even so my obd1 plugs wouldn't plug into obd0 would they? Im running 220 injectors(I believe) from a sohc vtec which shouldnt be a problem. Also i think my buddy said my VSS looked like it might be a little broken, could that be it?

 

Your broken VSS would definately make VTEC not work.

The DA B16A came OBD0 or OBD1 depending on the model year. You have to have an OBD1 ECU for it to plug into a OBD1 car. So if it plugs in, you have an OBD1 ECU.

The head will also have a date stamp on it.

What SOHC engine are you running injectors from?

The OBD0, OBD1, and OBD2 injectors are all different.

 

yes i had a 90 rex with a 93 b17 and it need a resitor box and yes i know u have to have a VSS to make vtec on some my rex would not if my cable came out of vss my .02 hope it helps

 

So what resistor box would i need to get?