I am preparing a '94 Civic Coupe EX with a OBD1 B16a to compete in a 12hr enduro this Saturday. I was loosing VTEC at some point while testing on track last Saturday. VTEC always returned for the next session but went away everytime. I am thinking I have some sort of oil pressure or oil viscosity deficiency but would like to know where else to look. The car also did about 2hrs of dyno testing on Friday without any VTEC problems. I ran two ECUs while testing on track the condition occurred using both. No CEL code was given by either ECU. The primary ECU is a chipped USDM P28 running Crome and P30 base code. The coolant temp, and speed checks were not disabled. The other ecu is a JDM P30 that came with the engine. I have a moroso 5.5qt baffled oil pan installed on the car as well. Oil pressure was about 80psi on the straights and 70ish min while cornering (it was hard to watch the gauge while cornering).

Here is my list of planned remedies:
1. Burn a chip with the coolant temp check and speed check removed
2. Shim the oil pump
3. Change oil type to 10-40 from 10-30
4. Replace VTEC solenoid and screens/filters

This is what I would like to know:
1. What else should be on my list of remedies?
2. How much oil pressure is too much?
3. Will the VTEC solenoid from a D16Z6 fit/work properly?

Thanks for your help. Hopefully we'll be able to shock some 1.6L Miata owners this weekend.

 

overfill 0.5L and use thicker/better oil.

your oil pressure sounds alright.

 

That oil pan is your issue, as well as what pat said.

Were is john A. And his nationals no vtec issue....

 

Is that specific to b series motors? Or can it be applied to other vtec motors?

My h22 drops out of vtec sometimes. (autox)

 

check your vtec soilnod.

 

You never searched the forum... this issue has been covered.
I do give you kudos for giving plenty of information especially about the baffled pan and noticing changes while cornering.
Thats classic vtec loss... lack of oil is your culprit.

 

Do you have any technical reasoning for asserting that the oil pan is the issue? I tried running a stock pan on the D16Z6 and had this problem until I shimmed the pump and added a moroso pan. Others who have raced with that engine in my area had similar issues until running a baffled pan and shimming the pump. The two moroso pans look similar to me so I would be surprised if the D-series one works well and the B-series does not.

 

How? I tested the solenoid for resistance per the service manual.

 

I searched this forum and a few others looking for relevant information. That is partly how I determined what information to provide. I agree oil is the most likely cause but I would like to address everything even items that only have a 5% chance of being the problem. While I was searching I found that some had VTEC issues due to sensor failure and I didn't know if my car's symptoms indicate an issue like that, lack of oil, or something else.

Thanks for your input, I will work on increasing oil pressure.

 

I run the D16Z6 and filling it just past full takes care of the issue.
This is with a stock pan.
No issues since.

 

I had a problem of losing VTEC when running my B16A2 w/ JDM P30 in my EK at the track.

What the culprit ended up being was VSS prongs where corroded. It seems coolant drained into my VSS from the heater core hoses and had sat when the motor was out of the car. It corroded the prongs on the VSS itself. This didn't throw a code nor acted any different that normal except for fact that VTEC stopped working and actually the speedo bounced around sporadically swinging from 0-260km/h and anywhere in between. This had happened on the street a couple times but only after driving for a long period of time. I mainly noticed when in VTEC for long session at the track. It was kicking out of VTEC and the speedo was bounce, it'd been out for a while so the motor was pretty heat soaked I didn't remember it happening until the motor was pretty heat soaked. Anyway, I came back to the pits, took the VSS out and scraped and cleaned the prongs as much as possible and then put some diode lithium grease on it. I never had problem after that.

So in short, try cleaning or running a different VSS and see if that works.

 

Is there a problem with the moroso RR pan ?

 

Yes i do.

I analyzed the data (lat and Log accelerometer, oil pressure sensor and oil temp sensor combined with track map), and saw that it was a pick-up issue.

John A's teammate was running a B series too, as well as several other people. No one else was running that pan though. And he was the only one having the issue.

We ran the D16z6 from 93-95, and then again from 2001 to 2007. Won many races, including the 25hours of thunderhill with that motor 2 times. NEVER ONCE had an issue with oil pressure dropping because of Lateral Gs. Never had to do any shimming of the oil pump either.

The last motor ran and won the 25 hours of thunderhill, 2 seasons of sprint racing, and is now being ran in SoCal in ITA. Still zero issues with oil pressure. He took a look at the bearings after i sold it to him, at my suggestion. They all looked perfect.

John G, used to race in PacNW, came down and ran with us a few times. I remember him having some problems when he first switched to the z6. I wasn't sure what the issue was though.

 

make sure ur vtec solenoid is working properly and is clean ! if not get a another 1. iv had this problem b4. i would loose vtec after the first time starting the motor and going into vtec.. i would need to re start the car every time and vtec would work again... after changing the solenoid the problem was gone...

 

Had this exact same problem with my road race civic. I would lose VTEC at exactly the same point on the track. If your running an S300 log AFR and what what happens when you lose VTEC, you see that the car runs very rich. This is because although the VTEC solinoid is on, there is not enough oil going to it so the ECU fuels for VTEC but mechanically the VTEC is off.

Guess what, I was also running the Moroso RR pan. Took that off and problem solved. I am not sure what exactly happens with that pan but it is (at least in my case) the problem.

If you want to find out exactly what is going on, i suggest you start by logging VTEC on/off, oil pressure overall, oil pressue at the VTEC solinoid galley.

 

On a B or a D ?

 

You guys datalogging this stuff, thank you for the effort. That is some seriously helpful information

 

u need to remember when using the moroso pan ! it takes 5 quorts of oil.. not 4.. maybe thats the problem

 

Thanks to everyone for your input.

I changed the solenoid, used 5-40 Shell Rotella synthetic, and shimmed the pump with an average sized washer. With these changes the VTEC worked through 11 hours and 15min of the race at which point the car began consuming oil quickly. I think the switch to synthetic oil and the oil pump shim solved the problem. Even with the shim I didn't see oil pressure past 85psi but didn't see pressures below 80psi in regular sessions. When I got into the car with an hour and a half to go oil pressure never reached past 60psi. I assume the drop in oil pressure was due to extremely high oil temps after running that long but I didn't have an oil temp gauge installed.

I did not bother burning a chip w/o the VSS sensor and coolant temp check disabled and I think it's safe to says those items were not giving me trouble.

Based on my experience and the information provided here I would do the following to ensure that VTEC functions while on track:
-Use some kind of 40W synthetic oil
-Run an oil accumulator
-Shim the pump if VTEC still does not function properly

Other notes:
-I run a moroso drag pan with a kicked out sump and corresponding pickup not the RR pan. I opted for that pan because I had success with the d-series counterpart
-JohnG ran a stock pan but never completely solved his VTEC issues, I think he also ran a shimmed pump.
-Portland, where this race occurred is an unusual track in that it runs clockwise and is completely flat (no banking). That might explain why solutions that for others don't work for us.

 

if you haven't taken the oil pan off, go ahead and do soo.. and check out the screen on the pickup

 

There are some unexplained anti-moroso propaganda in this topic. Just to get the facts straight :

The B series RR Moroso pan is an incredible parts that should be used by every B VTEC using sticky tires on the track.

The D series OEM Z6 pan is perfect as is as fare as oil starvation is concerned.

Any DRAG moroso pan should NOT be used on a road track.

End of the story !

 

Without reason/s or facts your comments are no better than the propaganda and proliferations of unfounded information expounded in the posts above.

 

Look at the pictures of the drag pans and compare it to the RR pan. Itīll explain a lot.
While hard cornering the oil can move to the left and to the right. While this happes there is a good chance for the pump not be able to pick up enough oil.
The baffles in the RR pan prenvents the oil from beeing pressed left and right.

After the thread opener corrected itselfes about which pan he was using Iīm sure the drag pan is the reason.

 

hondaapi wrote: "Look at the pictures of the drag pans and compare it to the RR pan. Itīll explain a lot."


Have you ever looked inside the Moroso Al wet sump kicked out oil pan? Once inside the gated pick up coral oil can not move to the left and to the right any large amount.

 

Sure

I've been having oil starvation issues with a B vtec without baffles, even overfilled 0.5, using high end street tires and even worst with R compounds. It shows on the crank bearings that I have changed and am now using the RR B vtec pan and it works fabulous after 2 seasons of abuse.

Never had a single problem (lived or seen one) with D vtec.

My english sucks, but it was pretty obvious from my post that what I meant was from personnal experiences...