jdmitr

He guys I am really stuck on this one. Help me out!! I do swaps all the time, and I have been chasing this problem for a day now!!

This is what I did:
- JDM H22a swap
- 1994 Prelude (H23)
- Ran 2 wires for Vtec to the factory locations, and grounded the pressure switch to the main ground below it.
- Undid the wiring for the ext. coil, and lengthened it to the dist (blk/yel)
- Using JDM P13 5 spd ECU,

First off I own the 94 Honda Prelude service manual.

The problem:
- No vtec
- Revs to H23 rev limit 6500

What it does right:
- Everything but up above, Idles fine, and drives great!!
- NO CIL !!! (and yes it comes on and goes off on ign)

Things I've checked;
- I have several P13's (5spd) I have tried them all, and same luck
- all Wiring there has continuity from ECU to Switch, and solenoid,
- Ran all the tests for Vtec except checking engine oil pressure (don't have a gauge) Everything checksout great as far as the sensor and solenoid is concerned.
- changed the wiring for the none External coil.
- jumped the ECU and no codes
- Drove the car for over 4 miles at const. throttle (hwy) to see if I got any CIL and did not.
- Found to pins on the ECU that did not have anything in them (Service manual showed them having pins) A8 (shared with A7 connected to fuse panel), and A22 (shared with A21 connected to the ICM), I connected them
- Checked to make sure you didn't have to switch the 2 pins like the 5th Gen accord, and you don't

So as you can see I am at a loss....HELP ME OUT!!

Nick M

something is keeping you in limp mode

its really hard to diagnose via the internet, especially since it seems you covered all the bases


check and re-check and re-check your wiring

Jason kiDD

If I help you out can I get one of those several P13's???

Anyway according to your description you need to wire the solenoid which has two wires. One wire goes to the factory vtec pin on the ECU the other to ground. And the Oil pressure switch is a one wire that goes to its factory location as well.. The way you described it you grounded the oil switch..

Also make sure that the car is fully warm and your oil levels are right. Otherwise vtec will not activate.

Shakes

even if he grounded the wrong wire why would it only rev to the H23 limit? wouldnt it just stay on the smaller lobe until 8k?

Jason kiDD

No because the p13 doesnt work that way.. The small lobe only goes up to a certain RPM, hence why there are two and why switch over. You will always get a cutoff @ 6.5k once vtec is not engaged..

prelittlelude

no in limp mode on the 4th gen the rev limiter is set some where around 6500 on the h22a1

jdmitr

Go look at yours if you have a Vtec engine. The pressure switch sits on the side, and has (2) wires going to it. This is the pressure switch. The solenoid is the barrel lookin thing that sticks upand has a single wire with a grey plug on the end. That is the Solenoid. I did not wire them wrong.

I agree I am in limp some how but can't figure it out.

Jason kiDD

lol I do have a vtec engine. But that is the only reasons why vtec would not engage. Low oil, tach not working, engine still cold, or a CEL.?

Is your odometer and speedometer working..?

prelittlelude

hes right, something is keeping vtec from crossing over. the rev limit set at 6500 is to protect the engine from damage becasue "ideal" conditions doen't exist for high revs. if i were you i would check you helms manual and start the troubleshooting flow chart for why vtec isn't working. i know one time due to my front balancer shaft seal i lost alot of oil and i hit the rev limiter at 6500 and was very confused, but it all made sense after i found out oil was the problem. many coditions must exist for vtec, and you won't alwasy get a CEL if one of those conditions is not ture. first and for most check the oil. then make sure the car is warmed up and that the VSS is working properly meaning the car speedometer is working and the tach is reading the correct rpm.

preluder

hell yeah check your oil that could be a reason like jason kid said too

CHK4TIX

ok, i will put my input on this as well. when i did my swap i kind of had the same problem. After letting my car warm up it wouldn't switch into vtec. I checked everything everyone told me to and it ended up being a dented oil pan. After i pounded out the dents, vtec work but not all the time. so i did some more checking and It ended up being my ground wire. i had it grounded right where all the other wires were but it didn't seem to work, so i grounded it where the battery grounds to the frame. Since then i haven't had any probs with vtec.

summery
check for dents in oil pan, pound out. check ground wire, fix if needed. reset the ecu, send one of your extras to me

spoolinlude

limp mode.......... sounds like he's stuk in h23 mode...... haaha............ bad joke

jdmitr

I don't know why you are laughing "Kidd"? I wasn't making fun of you, I was just simply pointing out that "if you own a vtec motor you should look at it, because if you know what to look for in wiring problems then you should know that the Solenoid only has one wire and is a completly different plug from the pressure switch!!" Don't take offense! I've done a dosen swaps of all kinds, and never had a problem like this.

By the way as I said earlier, I had not checked the oil pressure, well this morning after I posted I checked one of the most obvious places for low oil pressure "oil pan", and sure enough it was dented!! So I pounded it out and works like a champ!!

Thanks for the responses guys!

Jason kiDD

No offense taken homey. I was actually laughing at myself because its been such a long time since I had to wire up anyone's vtec so I messed up on the wiring.. Glad to see you got the problems fixed though, drive safe.

satan_srv

what do you mean the engine light comes on and off? If it's on for any length of time while the car is on stick a paperclip in the jumper and find out what it is.

jdmitr

Just so you know, when you turn the key to on, on a Honda the CIL comes on for a sec, and then turns off. This is to let you know that the MIL is functioning properly! Problem has been solved however.

Thanks anyway!