NotNew

I searched ALOT but I cant find problem, the ECU is not throwing any codes, I hooked 12v to the VTEC solenoid and it clicks which makes me think its fine, I tried grounding the pressure switch wire, and jumping it to the solenoid wire and it still doesn't work, is there anything I could be overlooking? Im running P28, just put in a new 02 sensor and knock sensor and it runs great, just cant figure this out.. bad ECU maybe?

36Chitownrunnin

try using a gsr ecu p72, also did you repin your plugs?

Hanmin

what car? is your speedo working?=

NotNew

its a 93 coupe EX. The swap was in it when I got it, and its running the P28 ECU. What pins do I have to relocate? The O2 sensor was unhooked, so I found the wires and hooked it up, and there was no wire for the knock sensor at all, so I used one of the pins from an A/C wire (sincs A/C was removed) and put it in the right spot in the ECU plug for knock sensor and ran that wire. The CEL turned off and doesnt throw a code any more, so I think I did that stuff right. I hooked an LED to the VTEC output on the ECU and it doesn't light up so I know its not the solenoid.. the engine harness has a lot of splicing in it and its tucked but i pulled it all out today and sorted everything and I cant find any bad connections, I took off all the loom and everything looks good, I also checked all the pins and wires on the ECU to a P28 Diagram I got from another post on here and I cant find any reason for it not to work.. and ya speedo works..

NotNew

bizzump

CTR_B

iTrader: (1)

Take of the vtec solenoid and clean the metal screen thats in there by wiping it with a rag.. and clean the ports of which it bolts to.

Make sure your VSS is in good working order.

Make sure your knock sensor is wired up and your ecu is reading it.

Make sure your oil pressure switch it hooked up and working

MAKE SURE YOU HAVE THE RIGHT ECU

Hanmin

im pretty sure that the p28 doesnt look for a knock sensor. Alot of people run a p28 with everything. I guess the only thing you an do is clean your solenoid and make sure everything is wired up. And you can try the ecu in another vtec car and see if it works .

NotNew

ya im trying to get my friend over here who has the same ECU to see if it will work in my car. The weird thing is that there is no CEL and no codes, which should mean its reading knock sensor and MAP sensor and VSS so I don't see a reason for it not to have VTEC. I have a LED on the VTEC solenoid wire and its not lighting up when VTEC should hit so I know the ECU is not putting out the signal to the solenoid.. im just trying to figure what might make it not work and not throw a code at the same time.. also P28 doesnt use a knock sensor so I guess i can take that back off lol..


Modified by NotNew at 11:31 AM 8/31/2008

94EG8

possibly bad ECT, weak oil pump, even a dent in the bottom of the oil pump has been reported to cause vtec not to function. Is the P28 chipped for a GS-R?

NotNew

yes P28 is chipped for GSR, and I just put the ECU in my friends car and it works fine in his car so its gotta be something in mine that's not turning on the CEL..

gsrhatch2356

there are like 4 things that have to happen in order for vtec to kick in
1. closed loop operation (make sure the vehicle is warm)
2. VSS has to read at least 11mph
3. Oil pressure has to be atleast 45-55psi ( I cant remember the exact number but is around there)
4.Have to be at the designated Rpm range.

if you cant supply power to the solenoid and car start idling really funny then I would suspect that. if it does then move on. the other thing is to check oil pressure, this can tell you alot about your vtec so just make sure that you can get at least 60psi when on the throttle. gl

NotNew

Might be on to something here ill update when I get it fixed


Modified by NotNew at 5:00 PM 8/31/2008

egallmotor12

check the pins in the ecu make sure there all str8

slvrcvc93

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by egallmotor12 &raquo;</TD></TR><TR><TD CLASS="quote">check the pins in the ecu make sure there all str8</TD></TR></TABLE> Didnt you read that he has no check engine light. Check for oil pressure.

NotNew

**ok little update-vtec is functioning now, but it runs SUPER shitty above about 4500-5K (well before vtec). Cuts out really bad and start backfiring and just runs out of power, and you cant tell vtec is working except my test light lights up on the vtec solenoid wire. I put a fuel filter on it and turned up the fuel pressure thinking it was running out of fuel but no luck. So no my question is what would make it do this without throwing a code? Seems like im narrowing it down but without a CEL its like guessing..

NotNew

ok guys I think i got it fixed!!!! I have no fuel pressure gauge yet but i adjusted the regulator all the way up, and it ran a little better, then I just started adjusting it down half turn at a time and voila! no more hesitation and vtec hit pretty hard, so I think when i buy a guage tomorrow I can actually see what the pressure is and fine tune and I think its good to go!!
THANKS FOR ALL WHO ANSWERED AN PM'd really appreciate it