Need advice as to what would limit an engine.

4721 Views 25 Replies 10 Participants Last post by ludesrv, Jan 21, 2007

ludesrv

Discussion Starter · Jan 19, 2007

My friends swap took a bad turn recently. We swapped an H22 into his 90 accord. Everything went well with the swap. Mechanically it's mint, makes me want one, but electronically it's not going to good. The CEL never comes on when driving. The engine runs mint, idles smooth and pulls HARD.

Here's the problem, it pulls hard till 6500rpm, then hit the red line. No engine light will come on. The CEL reads no codes. Then you do a fourth gear pull. At 6500rpm when it hits the limiter it falls out of vtec, and throws code 22. If you do a fifth gear pull, it only goes up to 5500rpm or 180kmh.

Things we have done:

- Quadruple checked the VTEC wiring, added solder to poor looking connections and replaced all vtec sensors with known working ones
- Replaced all heat sensors and double checked the extended wires that we did
- Banged out a dent in the oil pan just in case
- Changed to oil to thicker oil
- Used a p28 ECU to check the wiring. Went up to 7500rpm before throwing code 22.
- Used another P13, 6500rpm cut.

I'm confused as to what else to check so I'm asking others, what would limit the engine from revving to 8000rpm? If you cross 2 heat sensors (plug them into the wrong one) would it make a difference? The engine runs very warm (normal temp) and has no issues other then the revving. Really getting to me now. I'm taking a volt meter to the ecu tonight to see WTF is going on with the sensors.

1 - 20 of 26 Posts

SETI20

· #2 · Jan 19, 2007

Isn't a code 22 the vtec oil pressure code?

I don't think the H22 has a pressure sensor on the head.
So what happens, is that at x rpm, the ecu wants to engage vtec, does not see the needed pressure signal, throws a code, and drops into safe mode.

You'll need to modify the ECU to fix this.
Either with software, or by soldering a wire connecting 2 points on the back of the board, to fake the signal.

ludesrv

Discussion Starter · #3 · Jan 19, 2007

It hits VTEC fine until 6500rpm, then bounces off rev limiter in vtec. I know code 22 is oil pressure and it only get thrown in 4th gear at 6500rpm or 5th gear at 5500rpm.

The h22 has a vtec oil pressure sensor on the vtec sensor just like the USDM vtec engines and alot of other vtec engines.

We do not want to modify a perfectly fine ecu (worked till 8000rpm in my prelude) to make it work. Somewhere there is a mess up and we want to fix it properly, not rig it to work. I need suggestion, as wild as they are. If you want more info ask, I don't know what to post when asking for help lol.

jfrolang

· #4 · Jan 19, 2007

Not trying to tear you down, but maybe the CRX Community isn't the best place to troubleshoot an H22 Accord swap.

The only thing I can think of is that the ECU is running in safe mode.. but with no codes I have no input.

Baker

· #5 · Jan 19, 2007

jfrolang said:
Not trying to tear you down, but maybe the CRX Community isn't the best place to troubleshoot an H22 Accord swap.

I thought the same thing when i read this.
I wouldn't go to an Accord site to troubleshoot a b series Crx swap.

SETI20

· #6 · Jan 19, 2007

Also a good chance that the sensor uses a different resistance.

ludesrv

Discussion Starter · #7 · Jan 19, 2007

SETI20 said:
Also a good chance that the sensor uses a different resistance.

That's what I was gonna use.

I'm not asking you to figure out the problem, I'm asking what would limit the engine from revving. It could happen to a B series...or a H powered CRX...

But I can see that there will be no help here. Too bad, figured someone with an H in there rex would help me.

PS: Honda-tech accord site yielded no help either...neither did Toronto accord club or toronto prelude club. I'm running out of places to ask so I figured maybe the CRX guys might know.

SETI20

· #8 · Jan 19, 2007

Well, you already have your answer.
Code 22 will throw you in limp mode. That will most definately limit the output.

ludesrv

Discussion Starter · #9 · Jan 19, 2007

SETI20 said:
Well, you already have your answer.
Code 22 will throw you in limp mode. That will most definately limit the output.

HAve you not read?

The CEL ONLY comes on when topping 4th or 5th. IT will NOT come on when in 1st, 2nd or 3rd. Infact, you can bounce off rev limiter (6500 when it should be 8000) all day in 3rd and the light won't come on. You can reset the ecu and vtec till 6500 with no cel. I wanna know WHY isn't in going above? What could limit it with no CEL?

PS: I don't wanna sound/ act like a dick. I'm just out of ideas and places to look for help. Seems like this little bug is bigger then me and about 3 other forums.

Tonight I'm doing some tests with the volt meter and the p28 ecu on the vtec pressure sensor to see whats going thru it at 6500 and 7500 rpm.

SETI20

· #10 · Jan 19, 2007

From my experience, problems with sensors, mostly pressure and temperature sensors, will cause a lower rev-limit.

This is due to certain safety restrictions with misreadings in the software.
There's a certain threshold for it to throw a code and dump into limp mode.

I don't know if I'm right, but I thought I picked up that you mixed and matched parts with a swap?
I'm suspecting the ECU and some sensors are not getting along. That's a fairly common problem with older cars and newer engines.

What ECU are you running? What engine did it used to drive?
Was the engine capacity the same?
Was the OBD type the same?
Did it drive an engine in the same engine range?

For instance, you can drive a D16 with a PR3 or P30, even a P72 if you'd try hard enough. Doesn't mean you won't run into problems along the way.

See less See more

SIred91

· #11 · Jan 19, 2007

make sure the ecu matches the year of motor?

Did you do the 0BD1 swap or keep it 0BD0?

Buy a harness or did his own wiring?

Try preludepower.com for the 3rd gen guys..Lots of H swap knowledge there and the car is very similar.

Or try PGMFI.org for the wiring gurus.

ludesrv

Discussion Starter · #12 · Jan 19, 2007

SETI20 said:
From my experience, problems with sensors, mostly pressure and temperature sensors, will cause a lower rev-limit.

This is due to certain safety restrictions with misreadings in the software.
There's a certain threshold for it to throw a code and dump into limp mode.

I don't know if I'm right, but I thought I picked up that you mixed and matched parts with a swap?
I'm suspecting the ECU and some sensors are not getting along. That's a fairly common problem with older cars and newer engines.

What ECU are you running? What engine did it used to drive?
Was the engine capacity the same?
Was the OBD type the same?
Did it drive an engine in the same engine range?

For instance, you can drive a D16 with a PR3 or P30, even a P72 if you'd try hard enough. Doesn't mean you won't run into problems along the way.

ECU = P13
Engine = OBD1 H22A (JDM) Tranny is the perfect match, no lsd.
Old engine = OBD1 F22A4 SOHC non vtec
OBD = Same

All the parts are for a prelude except for the mechanical peices. All the sensors are prelude ones. The only sensor not prelude is the temp sensors, they are accord sensors as the H22 ones were all broken and the water neck was missing a sensor all togeter. I figured a water sensor was the issue and those are all getting check along with the vtec oil pressure sensor. does anyone know the proper read outs of these or do I have to trial and error with other ecus?

SIred91

· #13 · Jan 19, 2007

pgmfi.org...............srsly 8)

crxfisher

· #14 · Jan 19, 2007

SIred91 said:
pgmfi.org...............srsly 8)

Yeah, where's Synoptic when you need him? 8)

mattminerDOTcom

· #15 · Jan 19, 2007

hows the oil pressure when the sensor throws a code? the VTP is not a variable output, its a switch, like the idiot light on your dash.

as a test, jump the VTP wire to the vtec solenoid wire to bypass it and see if you still have an issue.

[email protected]

mattminerDOTcom

· #16 · Jan 19, 2007

also, you are 100 percent positive that this ecu is working properly in another car?

even if you throw a VTP code it shouldnt mess with your rev limit....

[email protected]

ludesrv

Discussion Starter · #17 · Jan 19, 2007

mattminerDOTcom said:
hows the oil pressure when the sensor throws a code? the VTP is not a variable output, its a switch, like the idiot light on your dash.

as a test, jump the VTP wire to the vtec solenoid wire to bypass it and see if you still have an issue.

[email protected]

How do I jump it. Sorry, wiring is new to me as of last sept when I did my own OBD1 conversion. Before that I had watched people wire my stuff, and had done half of my own MPFI, now I love wiring, but still getting into it is hard without a friendly hand. By jump, you mean throw a 12v to it?

ZeniceguyCRX

· #18 · Jan 19, 2007

are u losing fuel preasure?
long pulls....
4th5th up high rpm, you might be losing the needed fuel to keep up

91crx_si

· #19 · Jan 19, 2007

http://tech.hybridgarage.com/tech/codes.html

ludesrv

Discussion Starter · #20 · Jan 20, 2007

ZeniceguyCRX said:
are u losing fuel preasure?
long pulls....
4th5th up high rpm, you might be losing the needed fuel to keep up

Fuel would not cause code 22 to happen. It would cause code 23, knock.

And the code page really doesn't help...because we already established that code 22 is the only code thrown and we already knew what it was.

1 - 20 of 26 Posts

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