TeamCapri

Tech, Repairs, Upgrades => Capri XR-2 89-94 => Topic started by: rls120 on June 19, 2017, 12:37:31 PM

Title: Weird problem. . . .
Post by: rls120 on June 19, 2017, 12:37:31 PM
Hi everyone: 
I'm new here, just bought a '91 xr2 for my wife a few weeks ago.  We love the car, and I've spent a lot of time lurking on this forum.

We have a strange problem with it that I thought one of you might be able to shed some light on.  It very occasionally will smoke (looks and smells like oil smoke) A LOT, and run on 2-3 cylinders.  Most of the  time, I park it overnight, and its fine the next morning:  runs fine, zero smoke.  I've run it hundreds of miles between 'episodes'.

It did this yesterday, but this morning its no better.  Runs awful, smokes like a fog generator.  I'm running out of ideas.  Based on information gleaned from this forum, I've done the following already.

Removed and checked the intercooler (no oil in it).
Checked the turbo (no play)
Cleaned both ends of both engine ground straps.
 
I'm waiting on a new valve cover gasket so I can take that off and seal the baffles, and a new pcv valve is in my near future, once I find one.  This issue is so weirdly intermittent that I doubt if its either of those.

Do any of you have any other ideas?

Thanks in advance!
Title: Re: Weird problem. . . .
Post by: SHOwn on June 19, 2017, 01:47:48 PM
Welcome to the Forum!
You are checking the right things in my estimation. Can you find traces of oil in any intake piping? Look at the pipes that feed the turbo, and even the throttle body inlet. If what you posted is true, I would think your PCV could be an issue, but if you aren't seeing oil in any related hoses, I'd wonder.  Bypass (blowoff) valve hose clean? If baffles are to blame, you'll find plenty of oil in the driver's side valve cover vent hose going back to the flex intake hose. That will coat your turbo inlet. You can replace the (s shaped) vent hose with a breather filter and cap off the connection to the flex intake to check it. If that solves it you'll find oli in the breather and no exhaust smoke. That points to baffles or bad blow-by.

If that s-shaped hose from the valve cover has no wetness, I doubt your baffles are to blame.
Title: Re: Weird problem. . . .
Post by: rls120 on June 19, 2017, 05:14:56 PM
Thank you, SHOwn!  You've given me a few things to check, and to think about. 

Not being very familiar with the inner workings of Turbo systems (I've owned several, but have never had to actually wrench on one), I don't know where the by pass (blowoff) valve is located.

I'll check that vent tube right away.

Thanks again.
Title: Re: Weird problem. . . .
Post by: SHOwn on June 19, 2017, 10:45:26 PM
No problem. The bypass valve is on the driver's side of the engine. Follow the metal bypass tube that comes off the cone shaped cast aluminum intake (connects to the throttle body). It leads down the driver's side down near the top of the bell housing. The metal pipe gives way to rubber hose that connects to the bypass valve which takes excess boost (when dropping rpm to shift) and rerouted it to the side of the turbo inlet. Just look inside the piping and hoses for oil and trace it back if you find any.

If that valve cover breather s-shaped hose is dry, I really think you are dealing with a PCV issue. If all the intake and vac hoses on the driver's side are dry, and the throttle body isn't wet, all I can think of is PCV or something really wrong with a valve stem seal.
(http://i913.photobucket.com/albums/ac337/rapidcad1/image_zpsxmtkmgbq.jpeg)
Title: Re: Weird problem. . . .
Post by: rls120 on June 20, 2017, 11:17:03 AM
Thanks again for the info, and the picture.  It was very helpful.

I'm going in a different direction with this now, and I'm hoping someone out there may have had a similar problem.

I've followed all of SHOwn's suggestions, and I'm not finding oil in any of those places, including the pcv hose.  This morning I noticed that the tailpipe is very black, there's carbon on the ground below it, and it smells like raw gas. . .

I've never seen this before in 40 years of wrenching, but I think my supposed 'oil' smoke may be unburned fuel vapor, which would explain lots of things. . .  .

Problem is VERY intermittent. . . .characteristic of an electrical, rather than a mechanical issue.

Problem went away for at least a week at a time when it was dry. . .now we are in a rain sometime every day, very humid cycle. . . .which is when the problem cropped up again to stay, whereas the past couple of times it cropped up, it spontaneously (and completely) went away after sitting overnight.

So now I'm asking myself. . . .assuming my new hypothesis is correct. . . .what could be causing this. . .?

Bad ECM?
Fuel Pressure Regulator?
Injectors?
Anything else I'm not thinking of?

Any help will be appreciated.
Title: Re: Weird problem. . . .
Post by: chrispoe on June 20, 2017, 09:13:00 PM
I think you're on the right track, and most likely all that smoke is from misfiring as the fuel is being burnt in the cat which will result in the car running rough and smoking like a fog machine.

I would start with a general tune up.... distribitor cap/rotor, plug wires, and spark plugs.
Title: Re: Weird problem. . . .
Post by: Rocketman on June 20, 2017, 09:43:42 PM
Try swapping out the ECU. Ive seen this problem once or twice before - where it fires one bank of injectors constantly and floods two cylinders with fuel. Not sure what the cause is inside the ECU.
Title: Re: Weird problem. . . .
Post by: rls120 on June 20, 2017, 09:54:16 PM
Thank you both, gentlemen!  This is starting to make some sense now.
Title: Re: Weird problem. . . .
Post by: rls120 on June 20, 2017, 10:07:36 PM
Assuming I'm going to need to swap ecu's, do you guys have any advice for me about sources?  Junkyard, Autozone, etc.?
Title: Re: Weird problem. . . .
Post by: Rocketman on June 21, 2017, 12:28:30 AM
Junkyard, or forum members with spares
Title: Re: Weird problem. . . .
Post by: Rod Bacon on June 22, 2017, 05:27:28 AM
I have a spare Turbo ECU that's known to be good (removed it from my own car recently), but I'm in Australia and freight may be a consideration. Shout out if you get stuck.
Title: Re: Weird problem. . . .
Post by: rls120 on June 22, 2017, 03:29:10 PM
Well, I hope I can find one a LITTLE closer. . . . . :)

But I seriously appreciate the offer!  I'll be in touch if I can't find one on this continent.
Title: Re: Weird problem. . . .
Post by: rls120 on June 22, 2017, 09:50:41 PM
The internet, and forums like this one, are magical things. . . .

A total stranger from the other side of the globe offering to help out.  How cool is that?

I'm humbled.  Thank you, Rod, for making my day.
Title: Re: Weird problem. . . .
Post by: Rod Bacon on June 25, 2017, 08:16:54 PM
No problem at all. The magic of the interwebs...
Title: Re: Weird problem. . . .
Post by: rls120 on July 26, 2017, 09:32:31 PM
Update:  Secured a new (used) ECU from a local junkyard.  Installed it, no joy.  I'm going to replace the injectors next, just because I happen to have a spare set.

I've been second guessing myself. . . .am I sure its fuel, and not oil?  Had a friend sniff the exhaust tonight:  he agrees its definitely fuel. 

Do any of you have any other ideas for me, once I've replaced the injectors and STILL don't have a car? :D
Title: Re: Weird problem. . . .
Post by: rls120 on August 24, 2017, 10:00:32 AM
Further update:

1.  Replaced injectors with the set that came with the car. . . not known to be good:  just doing the parts changing thing to see what happens.
2.  Long story short, discovered that the intercooler was full of oil.  Interesting, because I had checked it when I first bought the car, and it was clean at that point.
3.  Cleaned the intercooler and piping, replaced the pcv valve, pulled the valve cover and sealed the baffles.  Also checked the turbo (again):  it has NO detectable play in it. 
4.  Started the engine and drove it a little bit.  The valve train was clattery, so I drained the oil.  Much fuel in it!  Replaced oil and filter, and we've got our car back:  runs great.  We've now put a couple of hundred trouble free miles on it.

Conclusions:  I've been chasing my tail.  It clearly originally had the fuel problem, because the oil was full of fuel.  I think that either the new ECU or the used injectors solved that, but I couldn't tell, because I still had smoke due to all of the oil in the intercooler.  Have I solved either problem?  I can't be sure at this point, but I'm hopeful.  Time will tell. 

We're just happy to have our awesome little Capri back.  It really is a delightful car to drive!  I'm just sorry we missed the Freeport meet.  Maybe next year.
Title: Re: Weird problem. . . .
Post by: SHOwn on August 25, 2017, 10:39:34 PM
Awesome! Keep an eye on it but it does seem like you figured it out, but I'm with you on the caution. I like that car is running right and not smoking and I can understand how too much fuel can flood the crankcase which in turn can thin the oil enough to vaporize it and send it throughout the induction system via the PCV pathway.

It would have been good to meet you at Freeport. You might have won a trophy just for showing up. I was late due to my daughter's Escape dropping half the exhaust system about halfway to Chicago, so I showed up right after voting and since I had the only 91 XR2 I won a trophy by default! Yeah maybe next year. Look what the Cubs did!
Title: Re: Weird problem. . . .
Post by: rls120 on September 12, 2017, 12:47:04 PM
It has been about a month now, and so far so good. . .(hope I'm not jinxing myself).  Thanks to all of you for your advice and good wishes as I worked through what appear now to be multiple problems.