Might have to pull the heads

[bryonbush 85]

For a while my motor has been burning oil. Initially it happened on start up and has been getting worse. I was thinking it's the valve seals and it still might be. Last few trips out I've been getting some backfiring when accelerating. I've replaced the plugs and made sure they were tight.  I took the valve covers off and I've got double springs so I can't see if the seals are bad. I'm wondering if there's a burned valve or one floating around. At this point I'm thinking I might as well pull them to check the heads real well and maybe see if the pistons are messed up. 

[rwcstang 201]

I had the same issues with my heads. The shop discovered the valve seals kept slipping, they were replaced but it never resolved my issue, they pulled the heads andI later found out the valve guides were installed incorrectly/Worn. 

for backfire, I would check the Distributor Cap and Rotor and also check the Distributor gear if it is worn out. I use a Brass Gear and I have to check every 3 months because I run a high volume oil pump. Debating to go with the normal pump and putting in my steel gear to eliminate this issue. 

[bryonbush 85]

1 hour ago, rwcstang said:

I had the same issues my heads, first the shop discovered the valve seals kept slipping, they were replaced but it never resolved my issue, I later found out the valve guides were installed incorrectly/Worn. 

for backfire, I would check the Distributor Cap and Rotor and also check the Distributor gear if it is worn out. I use a Brass Gear and I have to check every 3 months because I run a high volume oil pump. Debating to go with the normal pump and putting in my steel gear to eliminate this issue. 

Did you start to get engine run on when you turned off the car too? Mine has been happening more and more and I even have efi 

[Bob & Sue 110]

The valve guide seals could be causing your oil burn, you can rent from any of the usual parts stores a valve spring compressor without removing the heads.

https://www.oreillyauto.com/detail/otc-4538/tools---equipment-16488/tools-17919/rental-tools-16837/rental-tools--engine---clutch-19166/otc-engine-valve-spring-compressor/7928/4607081/1969/ford/mustang?q=ren

The backfire might be caused by a sticking lifter or burnt valve. 

[1969_Mach1 333]

New valve seals should help or stop the oil burning.  Aside from a leaking intake valve, popping through the intake when accelerating can be from a fuel mixture that is too lean, cross firing because of a bad spark plug wire, bad dist cap, or bad rotor.  If your firing order is 1-3-7-2-6-5-4-8 make certain spark plug wires 5 and 6 are not routed next to each other, if the firing order is 1-5-4-2-6-3-7-8 make certain spark plug wires 7 and 8 are not routed next to each other.  Also, make certain the mechanical and vacuum advance are working properly and the base timing is set correctly.  If you still have points in the distributor, as the rubbing block wears, the dwell increases and the timing retards.

If all the above tune up items are okay, do a compression test, or better yet, a cylinder leak down test.

Rebuilding cylinder heads on an old motor sometimes causes some other issues to crop up.  Oil burn past the rings, and/or the lower end wear fast.  Worse case is a knock from a rod or main bearing, wrist pin, or piston rocking in the cylinder will occur.  This is simply because rebuilding the cylinder heads on an old motor will increase the cylinder pressure.

[Vicfreg 771]

Sounds like a bad intake valve.  Hope not.  I would do a compression test.

[bryonbush 85]

this motor isnt but 4 years old and has the edelbrock performer rpm top end kit. so the backfiring occurred this morning after startup. this efi seems a little touchy at times during first start up till things warm up. then it wont happen the rest of the day. we're closing on our house on the 28th so till things settle down, this will probably have to wait. what im most curious about is if ill be able to notice anything out of wack while replacing the seals. 

what brand seals would yall recommend? 

[1969_Mach1 333]

Sounds like it might be running too lean for some reason.

If for some reason there is a leaking valve one quick check is to: (1) Remove the coil wire from the dist cap and connect it to a good ground.  You can use a simple 16 ga or heaver jumper wire with alligator clips at each end to ground the coil wire.  (2) Crank the engine long enough to hear the rhythm the engine has while cranking.  It should be a nice even rhythm.  If there are one or more cylinders with low compression the cranking rhythm will not be sound even.

Last time I purchased valve seals for a small block Ford I simply purchase a kit Ford Racing sold.  They are positive type valve seals (not Teflon).  They fit stock diameter valve guides.

https://www.summitracing.com/parts/fms-m-6571-a50/overview/

[barnett468 418]

21 hours ago, bryonbush said:

this motor isnt but 4 years old and has the edelbrock performer rpm top end kit.

what brand seals would yall recommend? 

most likely not a leaking valve or bad seals but you can check the valves when you get the heads off.

i would use the same style seals. they should press over the valve guide.

check the guides for wear also but they too are likely good.

[bryonbush 85]

i dont think im running lean. with this efi, it regulates my AFRs. and the obvious sight and smell of burning oil. I pulled the plugs a few weeks ago and some of them were pretty oil saturated while some looked good. these were off the passenger side bank. front to back goes from right to left. 

[barnett468 418]

you likely have a big problem like bad rings

[bryonbush 85]

that's what im wondering too. ive been getting blow-by out of my breather valve out of the driver side for a while now. which if that's the case, ill probably end up just pulling the motor since ill have the top end apart anyways.

[barnett468 418]

1 hour ago, bryonbush said:

that's what im wondering too. ive been getting blow-by out of my breather valve out of the driver side for a while now. which if that's the case, ill probably end up just pulling the motor since ill have the top end apart anyways.

ok, you have bad rings in the cylinders with the extremely oily plugs. major bummer. you can run heads with no seals and they will not dump nearly enough oil in the cylinder to make the plugs look like yours which is why i figured it was something other than valve seals.

 

[barnett468 418]

it does not appear to be too lean unless it is only lean at idle and deceleration (off throttle).

[1969_Mach1 333]

Number 1 cylinder doesn't look good.  Is this the first time that spark plug has looked like that?  Have you leaked down the cylinders or done a compression test yet?  At only 4 years old, I would do a little more checking before condemning the motor and puling it out.  Number 4 cylinder looks much leaner than 2 and 3, but that could be from either uneven fuel distribution through the intake manifold, or there is a vacuum hose connected to the runner going to #4 cylinder and a vacuum leak..

You should have easily noticed it wasn't running on all 8 cylinders.  It looks like number 1 cylinder has not been firing at all for a long time now.  Is the spark plug wire to that cylinder good?  That won't stop the oil burning, but just curious.  Curious, this won't stop the oil burning, but are you using the stock ignition system?

Lastly, if the oxygen sensor is on the side of the motor with one cylinder not firing, the oxygen sensor reading will be out of whack.  Usually, the oxygen sensor will indicate a lean A/F mixture with the additional unburned oxygen in the exhaust stream.  The EFI control module, should try to compensate by richening the A/F mixture.  But, with the additional oil, I'm not certain.  A factory EFI setup would have latched a trouble code and a check engine light would have come on.  I don't know if the aftermarket stuff has those capabilities.  

[bryonbush 85]

so the oil soaked plug is the #4 cylinder. im guessing that one is so bad due to that being the closet to where the vacuum line to the PCV valve is. But i added an oil separator on that a while ago. This is the first time the plugs have been changed. a while back when i first noticed oil coming out of the breather i did a compression test. all cylinders came in within 10 psi from each other at max difference. i haven't done one lately though. the efi AFR sensor  is on the driver side of the exhaust and the two sides are not connected by an h or x pipe. i don't think the #1 cylinder wasn't not firing, because it still pulls strong. im running an MSD 6AL box and MSD pro billet distributor.

if there was an issue with the valves not seating correctly or burned up, would this be a reason why id get more engine run on when shutting down? it would do it occasionally with my carb, and stopped with the efi. then it has been creeping back and now it happens all the time. 

[barnett468 418]

engine run on is mainly tuning. leaking valves will have a negligible affect on that. you can have good compression and still have bad oil rings.

if you get poofs of smoke out the breather with the pcv disconnected the rings are definitely bad.

the pcv can make one plug more oily that the others, but if it is doing that, it may be getting splashed with oil. it needs to be covered with a shield. you can put new plugs in it then plug the pcv and drive it for a while.

the pcv should go to the carb, not an intake port

the oily plug can cause a misfire.

 

[1969_Mach1 333]

Simple question, do your valve covers have baffles in them to prevent oil splash into the PCV and breathers?  Also, is the crankcase vented correctly?  PCV in one valve cover and a breather vented to the air cleaner or atmosphere in the other valve cover?

There is also the possibility the intake manifold gasket is leaking and pulling oil vapors from the crankcase into #4 intake port.

With an MSD ignition system, the spark plugs should be fairly white.  I don't believe #4 cylinder was firing.  I think you can open the spark plug gap 0.010" over stock with the MSD ignition.

[bryonbush 85]

2 hours ago, barnett468 said:

engine run on is mainly tuning. leaking valves will have a negligible affect on that. you can have good compression and still have bad oil rings.

if you get poofs of smoke out the breather with the pcv disconnected the rings are definitely bad.

the pcv can make one plug more oily that the others, but if it is doing that, it may be getting splashed with oil. it needs to be covered with a shield. you can put new plugs in it then plug the pcv and drive it for a while.

the pcv should go to the carb, not an intake port

the oily plug can cause a misfire.

 

My bad, the pcv is going to the EFI not the intake. Ill have to unplug the PCV and see what it does. 

11 minutes ago, 1969_Mach1 said:

Simple question, do your valve covers have baffles in them to prevent oil splash into the PCV and breathers?  Also, is the crankcase vented correctly?  PCV in one valve cover and a breather vented to the air cleaner or atmosphere in the other valve cover?

There is also the possibility the intake manifold gasket is leaking and pulling oil vapors from the crankcase into #4 intake port.

With an MSD ignition system, the spark plugs should be fairly white.  I don't believe #4 cylinder was firing.

yes the covers have baffles. PCV is on the passenger side rear and the breather is on the driver side front and is a filtered unit that is atmospheric. tonight i pulled the back two spark plugs as they have probably less than 100 miles on them. #4 looks heavily oil saturated right at the tip. the threads are dry. #8 isnt as bad, but there is wet oil going up the threads. i just did those as they were the worse from when i changed them and also will see if the oil is coming from the PCV and going right to the back side. Right is the #4 

[1969_Mach1 333]

In the pictures the spark plug at the left is a little wet.  But you mention the spark plug at the right in the picture is number 4. They are both black with soot from a rich A/F mixture.  Is that oil or fuel on the spark plug that is a little wet?   Either way, aside from one being a little wet, why is it running so rich?  Is there something strange happening with the oxygen sensor?  When those fail, they typically fail by not cycling fast enough or fail by being stuck sending a lean signal to the computer (PCM, ECM, I don't know what aftermarket calls them).  Does your EFI system have any self diagnosing capabilities?  MSD can easily clean up spark plugs if there is a slightly rich condition.  But even the dry spark plug is extremely rich.  The porcelain usually looks fairly white with an MSD type ignition system.

Also, if the engine vacuum is higher than normal (low numeric values) or the MAP sensor is bad, the MAP sensor will think the engine is under more load than it actually is and cause the A/F mixture to be richer than it should be. 

[Vicfreg 771]

I am thinking that this is a crankcase ventilation issue.  Not sure where the PCV valve is hooked to on your EFI.  It should go to the full vacuum manifold port.  Also, how much vacuum are you making at idle?  Is it steady, or perhaps a vacuum leak......

[barnett468 418]

1 hour ago, Vicfreg said:

I am thinking that this is a crankcase ventilation issue.  Not sure where the PCV valve is hooked to on your EFI.  It should go to the full vacuum manifold port.  Also, how much vacuum are you making at idle?  Is it steady, or perhaps a vacuum leak......

driving it without the pcv as i suggested will tell him for certain and eliminate any guessing about the valve causing the problem.

[bryonbush 85]

I posted pictures of the sparkplugs and the settings for my efi on the Fitech owners group on facebook and everyone agreed that im running super rich as well. my idle was pretty rich and cruise was a little on the rich side as well. im going to check the o2 sensor and see if its tight as well as other areas. I'm not getting any noticeable surging or idle issues that make me think there's a leak on the motor side. or maybe the o2 sensor is just fouled out and creating drama.

But the plugs do have oil on them as well which still leads me to believe that there might be a valve seal issue at least.

[1969_Mach1 333]

Do those aftermarket EFI systems have any diagnosis like the OEM's?  Where you can read inputs and outputs from sensors, actuators, in real time?

It might be worth just replacing the O2 sensor.  Fortunately, it's not on the side that has a wet spark plug.  How old is it?  O2 sensors do "wear out" and need replacing once in a while.  I'd check the engine vacuum as well.  Low vacuum will cause these types of EFI systems to run rich.

With both EFI and MSD ignition, I'd think those spark plugs should look almost new.

[ray1970 88]

With the fitech you can restart the learn thing..My help?

My unit got to the point where I had to hold the throttle to start it (not right for efi)

That was on ECU no.2

Whating for its return for ECU no.3  (ECU has been  back ordered for over a month )  Black screen syndrome

I have low vac.11-12 at best   WHEN the efi works it works very well..