B18C-R in EG won't pull at the top of 4th or 5th

We may earn a small commission from affiliate links and paid advertisements. Terms

B

BigBoulda

Junior Member
How's it going?
I recently put a JDM B18C-r into my 1992 civic DX hatch. I am running my stock P06 ECU that I had chipped, converted to VTEC, and set to stock ITR map specs.
The problem that I am having is that when I am accelerating hard in third gear, and then shift to 4th, at about 7200 RPM the VTEC cuts out, the car stops pulling hard (as it will without VTEC), and the rev limiter comes on WAY early at 7800 RPM.
I don't understand why this is happening, especially since it only happens in 4th and 5th gears (and sometimes at the top of 3rd). When it happens, The CEL comes on, and then the VTEC stops working in all the gears. Another strange thing is that when I shut the car off to check the CEL, it resets itself, even without disconnecting the battery. So there is no way that I can even check the CEL to see what the problem may be. I tried to jump the wire for the CEL with the car running, but it did not flash a code, the light just stayed on. But like I said, the second I turn the car off to get a code it won't throw one, and then the VTEC works in the lower gears again.
Everything I think it could be would affect the car all the time, not just in specific gears.
I have checked the oil level, and it is right where it should be.
I just put in a brand new O2 sensor.
What could it be? This car is not that fast without the VTEC kicking hard! Please Help.
 
Have you inspected the vtec solenoid? Pull it off, and have a look at the filter screen. If it's clean, open the solenoid and see that it moves freely by pushing on it with your thumb.

Also, I would try a known good ECU too. Not that yours is bad persay, just find one that works correctly and swap it in to emliminate that as a possibility.
 
Originally posted by 92b16vx+Jul 20 2005, 02:17 PM-->
92b16vx @ Jul 20 2005 said:
Sounds like you're losing oil pressure up high.
[post=528991]Quoted post[/post]​
Click to expand...


92b16vx@Jul 20 2005, 02:23 PM
Have you inspected the vtec solenoid? Pull it off, and have a look at the filter screen. If it's clean, open the solenoid and see that it moves freely by pushing on it with your thumb.

Also, I would try a known good ECU too. Not that yours is bad persay, just find one that works correctly and swap it in to emliminate that as a possibility.
[post=528994]Quoted post[/post]​
Click to expand...


:werd: :withstupid:

that pretty much covers all ov the stuff i was thinking
 
Originally posted by BigBoulda@Jul 20 2005, 01:09 PM
How's it going?
I recently put a JDM B18C-r into my 1992 civic DX hatch. I am running my stock P06 ECU that I had chipped, converted to VTEC, and set to stock ITR map specs.
The problem that I am having is that when I am accelerating hard in third gear, and then shift to 4th, at about 7200 RPM the VTEC cuts out, the car stops pulling hard (as it will without VTEC), and the rev limiter comes on WAY early at 7800 RPM.
I don't understand why this is happening, especially since it only happens in 4th and 5th gears (and sometimes at the top of 3rd). When it happens, The CEL comes on, and then the VTEC stops working in all the gears. Another strange thing is that when I shut the car off to check the CEL, it resets itself, even without disconnecting the battery. So there is no way that I can even check the CEL to see what the problem may be. I tried to jump the wire for the CEL with the car running, but it did not flash a code, the light just stayed on. But like I said, the second I turn the car off to get a code it won't throw one, and then the VTEC works in the lower gears again.
Everything I think it could be would affect the car all the time, not just in specific gears.
I have checked the oil level, and it is right where it should be.
I just put in a brand new O2 sensor.
What could it be? This car is not that fast without the VTEC kicking hard! Please Help.
[post=528988]Quoted post[/post]​
Click to expand...

I bet that code you are throwing is vtec oil pressure which is code 22 for me and I use to throw it at high rpm's in lower gears, and yep vtec would stop working until I turn the car off and turned it back on. It sounds like you are not getting proper oil pressure when vtec kicks in.
 
I can garantee you has something to do with the oil pressure switch. When you hook up a VAFC, if you don't connect the VTM (oil pressure wire) it does the exact same thing. Only other thing it could be would be the oil pump, but I would suspect that it would effect lower gears too. Check the connection at the ECU, make sure it is in the right spot, and connected well, if so, trace it back to the solenoid. Worse case scenerio is testing the pressure at the solenoid with a gauge.
 
You need to learn to check for cel codes. turn off car. put jumper in. turn the key to the on position, without turning on the car. here is a codes list here https://hondaswap.com/forums/index.php?showtopic=29806
Once you know which code you have, you will narrow your fixes. I was throwing a code 22 on my b16, which points to the vtec pressure switch, but it was actually that at high rpms my oil pressure dropped, so the switch wouldn't even open. It was actually my oil pan that was the real problem, but anyway...
If this method doesn't work, do what John says about the ecu and check your wires, and even swap out for a good ecu to see if that is the problem.
 
Originally posted by 92b16vx@Jul 20 2005, 01:17 PM
Sounds like you're losing oil pressure up high.
[post=528991]Quoted post[/post]​
Click to expand...


Thanks for all the suggestions.
I have tried swapping out the ECU for a stock P30 (from a JDM Si-r), and that didn't solve the problem. I check my oil level all the time, and it is always full. What would be causing oil pressure loss just in the higher gears? If it was an oil pressure problem, wouldn't it affect the engine at high RPM regardless of the gear? What I mean is, there is just as much stress on the engine at 8500rpm in 1st and 2nd gears as there would be in 3rd 4th and 5th right?
I took my solenoid off, and the filter is beautifully clean, and the solenoid traveled fluidly when I poked it.
Someone suggested that I switch to a solenoid with the oil pressure switch, but would this make a difference over having the pressure switch wire grounded straight out of the ECU (I read this is how to wire it for JDM engines without the PS).
Someone else suggested that on ECU's other than the P28, you have to ground the VTEC oil PS to A26 on the ECU, and not to the solenoid. Has anyone else heard of this.
I know how to check the CEL codes (I have done it several times), it is just that when I get the CEL code in 4th it will not flash a code at all. Whether I do the correct procedure of turning the car off jumping the wire, and turning the car on; or try to jump the wire with the car still running after the code is thrown, the CEL will not flash a code. For some reason, when I turn the car off, the CEL resets itself (even without dissconnecting the battery), so it won't flash a code, and if I jump the wires with the car running, the CEL just stays on without flashing.
 
Originally posted by BigBoulda+Jul 25 2005, 10:47 AM-->
BigBoulda @ Jul 25 2005 said:
92b16vx
Click to expand...
BigBoulda @ Jul 25 2005 said:
@Jul 20 2005, 01:17 PM
Sounds like you're losing oil pressure up high.
[post=528991]Quoted post[/post]​
Click to expand...


Thanks for all the suggestions.
I have tried swapping out the ECU for a stock P30 (from a JDM Si-r), and that didn't solve the problem. I check my oil level all the time, and it is always full. What would be causing oil pressure loss just in the higher gears? If it was an oil pressure problem, wouldn't it affect the engine at high RPM regardless of the gear? What I mean is, there is just as much stress on the engine at 8500rpm in 1st and 2nd gears as there would be in 3rd 4th and 5th right?
I took my solenoid off, and the filter is beautifully clean, and the solenoid traveled fluidly when I poked it.
Someone suggested that I switch to a solenoid with the oil pressure switch, but would this make a difference over having the pressure switch wire grounded straight out of the ECU (I read this is how to wire it for JDM engines without the PS).
Someone else suggested that on ECU's other than the P28, you have to ground the VTEC oil PS to A26 on the ECU, and not to the solenoid. Has anyone else heard of this.
I know how to check the CEL codes (I have done it several times), it is just that when I get the CEL code in 4th it will not flash a code at all. Whether I do the correct procedure of turning the car off jumping the wire, and turning the car on; or try to jump the wire with the car still running after the code is thrown, the CEL will not flash a code. For some reason, when I turn the car off, the CEL resets itself (even without dissconnecting the battery), so it won't flash a code, and if I jump the wires with the car running, the CEL just stays on without flashing.
[post=530724]Quoted post[/post]​
Click to expand...


I think, it's better to check your ECU connection.
It will be easier to find the problem with the CEL codes. It seems that your ECU is only connected when you switch on the car.
If you have an oil pressure default, the cel code will flash.
Good luck.
 
You should be able to go to a dealership and use a diagnostic computer to read for past codes also....If I am not mistaken. Just another option you could try doing....Good luck.
 
Originally posted by 92b16vx@Jul 20 2005, 02:35 PM
I can garantee you has something to do with the oil pressure switch. When you hook up a VAFC, if you don't connect the VTM (oil pressure wire) it does the exact same thing.
[post=529035]Quoted post[/post]​
Click to expand...


Well, I figured it out, and I feel like an idiot, but at least it didn't cost me any money to fix. When I read how to wire a JDM solenoid without the VTPS for VTEC, I missunderstood what it was saying. It said to splice the VTPS wire coming from D6 into the VTS wire coming from A4, and then to take the ground wire and ground it to the solenoid. This confused me because I didn't have a ground wire at all, because I didn't have a pressure switch (which was the whole reason I was having to do the wire fix). The article (written by Katman at ff-squad) was assuming that you were using a US OBD2 Integra wiring harness, for simplicity's sake (but I was using my stock DX harness for $ sake), so I didn't have the plug for the VTPS. So what I thought I was supposed to do is take the wire from D6 and ground it on the solenoid to make a circuit for the pressure switch. This made the VTEC start working, so I assumed it was right, but as I found out it wasn't. So finally, I did it right and tapped D6 to A4 (I didn't ground anything which I think shouldn't matter, because that ground wire is only connected to the clip which doesn't go to anything), and it fixed the problem. I pulled all the way up in 4th gear for the first time, and it was increadable. It sucked because I didn't splice the wires until about 5:00 pm, right in rush hour, but I needed to see if it worked. Lets just say 8000 RPM, in 4th gear, on the access road, in the 8th largest city in the country, at rush hour, is a little bit hectic!
Thanks for all the help. If this happens to help someone else out in the future it will make it a little bit more worth it.
 
Originally posted by becoming@Jul 26 2005, 08:59 PM
Good deal, glad ur shit is straight!
[post=531624]Quoted post[/post]​
Click to expand...

Hell yes, so am I. It is so nice to be able to pull through all the gears. Yesterday on the highway there was a long open stretch so I got on it. Got a little over 130 mph before I ran out of room, but I will tell you this, the car was still pulling, HARD, at the time I had to let off the gas (7300 rpm in 5th). I am interested to see if I can break 150, but I would need a llooonnggg stretch of open road for that death run.
 
You must log in or register to reply here.
Back
Top