TeamCapri

Please login or register.

Login with username, password and session length
Advanced search  

News:

New & potential members - due to overwhelming spam registrations, it's been very hard to sort through new registrations. If your account has not been approved, check your spam folder! If not please contact us at admin[AT]teamcapri.com and we'll sort it out for you.

Author Topic: past bogging/surging issues  (Read 3658 times)

belleaudb

  • Jr. Member
  • **
  • Posts: 75
    • 92 XR2
past bogging/surging issues
« on: May 25, 2017, 08:12:57 PM »

In the past I have posted that I have had problems with bogging and surging of my car. These problems were encountered from pretty much the first day I had the car 10 years ago. It seemed worse the longer the car was driven and higher temperatures. I had replaced all ignition components, had the injectors cleaned and flow tested, multiple ground straps from body to engine, replaced the VAF and verified fuel pressure while the car was surging. The spark plugs were quite white, indicating lean running.

Recently I noticed oil inside the J pipe and even had oil at the exit of the VAF. No shaft play at all in the turbo.

It was clear that the oil came from the fresh air vent into the valve cover from the J pipe. I pulled the valve cover and disassembled the baffle for the fresh vent air side. There was a ton of oil in the baffle, even at the point where the hose nipple is in the valve cover.

I noticed that there was no sign of gasket for the baffle in the area between the baffle opening and the far chamber of the baffle. So it appears that the oil was shortcut past most of the baffle. The valve cover has never been removed from the engine. I cleaned the valve cover and baffle with brake cleaner and resealed/installed the baffle.  I installed a clear hose between the valve cover and the J pipe.   

No more surging/bogging and the hose remained clear/clean over a 70 mile drive. The car is a joy to drive and accellerates strongly and smoothly even while cruising along at 25MPH in 5th gear.

Hopefully my discovery and repair will help someone else who is experiencing these issues.

Now my next project is full synthetic 75w-90 oil in the transmission and adjustable boost control to bring boost to 12-14 lbs.
Logged

greywolf27030

  • Old-Timer
  • *****
  • Posts: 1658
    • 1991 XR2, 1992 XR2, 1993 XR2
Re: past bogging/surging issues
« Reply #1 on: May 26, 2017, 12:15:22 PM »

Thanks for the info.  I never realized that sealing the baffle was that important.

Jack Byrd
Logged
Jack Byrd

Rod Bacon

  • Newbie
  • *
  • Posts: 24
    • 1993 XR2
Re: past bogging/surging issues
« Reply #2 on: May 28, 2017, 06:23:07 PM »

Is there any chance you can post a photo of exactly where you're talking about? I have a car with similar symptoms, but I'm not exactly clear on what baffle you're talking about.
Logged

belleaudb

  • Jr. Member
  • **
  • Posts: 75
    • 92 XR2
Re: past bogging/surging issues
« Reply #3 on: May 30, 2017, 06:28:56 PM »

You may want to search the forum for pictures. I did not take any.


There are 2 baffles inside the valve cover.  One is for the pcv valve and the other is crankcase ventilation. The one I sealed is the larger of the 2. It is retained with multiple (8?) phillips head screws. Remove the screws and gently remove the baffle. I cleaned mine with brake cleaner and removed all traces of the old gasket.
Logged

belleaudb

  • Jr. Member
  • **
  • Posts: 75
    • 92 XR2
Re: past bogging/surging issues
« Reply #4 on: May 30, 2017, 06:52:56 PM »

Here is a picture of the valve cover with the baffles removed. This picture is on the forum. I have downloaded it and modifed it showing where the sealer goes. Sealer is applied at the areas with red.

« Last Edit: April 12, 2018, 10:11:35 PM by belleaudb »
Logged

Gaz

  • Sr. Member
  • ****
  • Posts: 423
  • Do no harm, take no sh!t.
    • 92 XR2, 01 LL Bean Outback, 92 Concours, 86 F150
    • Saint Cloud Exhaust
Re: past bogging/surging issues
« Reply #5 on: May 31, 2017, 01:43:42 AM »

Kinda looks like a tesla valve.
Logged

Rod Bacon

  • Newbie
  • *
  • Posts: 24
    • 1993 XR2
Re: past bogging/surging issues
« Reply #6 on: June 02, 2017, 01:51:04 AM »

Thank you!
Logged

belleaudb

  • Jr. Member
  • **
  • Posts: 75
    • 92 XR2
Re: past bogging/surging issues
« Reply #7 on: June 05, 2017, 09:19:33 PM »

I just wanted to give some followup.

500 miles since the repair and still running great.  ;D The clear breather hose is still clear with no signs of oil.

Going to dump a bottle of Seafoam into a full tank of gas to cleanup the pistons and combustion chambers.

Changed transmission oil with 3 qts Redline MT90 and 1/2 qt Synchromesh.  Next project is to add 1/2" of high density foam to the seats to replace the old grey foam which has turned to dust.
Logged

NomakeWan

  • Full Member
  • ***
  • Posts: 162
    • 93 Capri XR2
Re: past bogging/surging issues
« Reply #8 on: June 06, 2017, 09:18:07 PM »

Want to go ahead and add my two cents. I too had tons of puking oil, I too found the turbo to have no shaft play, but sadly I had it rebuilt anyway (which caused more problems than it solved, of course). After looking up threads on Miata forums (and a 323 post, and a post here) about how much those baffles will screw you over, I took mine apart. I too found that, from the factory, it didn't appear they used any sort of sealant on my valve cover. I don't know if the sealant they used just disintegrated over the years or what, but I redid both baffles with black RTV and reassembled it. I haven't gotten the car running yet due to other problems, but we'll see if that does the trick.

belleaudb, did you not use RTV on the second baffle, the one on the far left in the photo you posted?
Logged

belleaudb

  • Jr. Member
  • **
  • Posts: 75
    • 92 XR2
Re: past bogging/surging issues
« Reply #9 on: June 07, 2017, 09:22:09 AM »

I never touched the smaller PCV valve baffle. Only the large crankcase ventilation baffle.

Easy check:  Pull the accordion air duct from the VAF outlet. If you see oil in the outlet of the VAF or oil is puddling in the lower "pleats" of the accordion air duct, where it connects to the VAF, you know that oil is coming from the crankcase ventilation tube. That tube is connected to the large baffle, shown in the picture I posted earlier.

I don't think a bad turbo would cause oil to puddle in the VAF or the air duct where it connects to the VAF. It doesn't seem possible that oil from a bad turbocharger could get that far "upstream" in the air filter system.
Logged

NomakeWan

  • Full Member
  • ***
  • Posts: 162
    • 93 Capri XR2
Re: past bogging/surging issues
« Reply #10 on: June 07, 2017, 08:45:29 PM »

I was young and stupid. ;D Live, learn an expensive lesson, move on.
Logged