Team Chevelle banner
  • Hey everyone! Enter your ride HERE to be a part May's Ride of the Month Challenge!

Status
Not open for further replies.
1 - 8 of 8 Posts

·
Registered
Joined
·
659 Posts
Discussion Starter · #1 ·
I have been having problems with excessive deposits on my plugs and the #8 plug fouls occasionally. I have posted some questions here before on the matter and tried some troubleshooting on it since but the problem persists.

To recap what I have done to try to fix the problem (283 2bbl, p-glide):

1. rebuilt the carb.
2. checked the plug wires / plugs.
3. changed valve cover gasket.
4. reset valve lash.
5. installed positive valve seals on #8 I/E.
6. adjusted timing / advance.

none has had a discernable effect.

The engine was rebuilt at some point in the past. I have done a compression test and all cyl. were OK.

Recently, I have noticed two things which might point to the cause:

1. after pulling the plugs recently, I noticed that the #5 plug was almost as dirty as the #8. This reminded me of a suggestion by someone here that my transmission modulator may be broken, since the vacuum connection is mounted in the manifold runner that connects the #5 and #8 cylinder. I had checked the modulator with a vacuum pump recently, and it did not leak down quickly, so I thought it was OK. I rechecked yesterday with the car idling in P, and it did leak down pretty quickly, and there was some transmission fluid in the lower section of the vacuum line. I did not notice any transmission fluid being drawn into the vacuum pump when I checked it, though. Could this be causing my deposits?

2. When I had my car idling with the air cleaner removed, I noticed some smoke coming out of the PCV port that runs from behind the distributor to the bottom of the air cleaner. It was not billowing out, just coming out about like the smoke from a lit cigarette. the smoke came out steady at idle and when I goosed the throttle, but stopped as the car was returning to idle. Since my compression was OK, could this be a leak in the intake manifold around the exhaust crossover?

I am hoping that the problem is in the top end of my engine (manifold or maybe heads). I am considering installing some vortec heads, a performer intake, and a four barrel, especially if it will cure my problem. I do not want to waste the money on a new intake if my rings are shot. If there is a problem in my short block, I want to get a crate 350 or 383 small block and get an intake to match it rather than my 283.

So wadaya think? Modulator? Intake? Rings? Other? Any suggestion will be welcome.

Thanks,


------------------
Charles Perrell
[email protected]
65 malibu SS Convertible
283 2v powerglide
 

·
Registered
Joined
·
290 Posts
There could be a leak.have you tryed a vacume gague to get readings.Anouther trick spray some carb cleaner where the intake meets the head a rise in rpm will conferm a leak.The smoke your seeing is normal called blowby but tha can get out of hand and cause biger problims.Hope i help somehow.


------------------
http://home.talkcity.com/sparkplugst/snakepell/index.html 66 396 Beaumont.
Once bitten twice shy.
Don Pell 66 396Beaumont.
Once bitten twice shy
 

·
Registered
Joined
·
4,548 Posts
<BLOCKQUOTE>quote:</font><HR>Originally posted by cperrell:



, and there was some transmission fluid in the lower section of the vacuum line.
<HR></BLOCKQUOTE>

It sure can be causing your deposits.
If there is any trans fluid in the vacuum line you can be sure that some is getting sucked in the engine. Maybe it didn't get into your vacuum pump because you didn't have it hooked up for very long. I would get a new modulator.


------------------
Undee's70SS
 

·
Registered
Joined
·
659 Posts
Discussion Starter · #4 ·
Thanks for the replys.

I am planning on changing the modulator.

Would more fluid leak out the modulator at high speeds?

What about the vapor/smoke comming out of the crankcase vent? Is this a sure sign of the rings being shot? If the rings are OK, what else could cause the smoke?

Thanks,



------------------
Charles Perrell
[email protected]
65 malibu SS Convertible
283 2v powerglide
 

·
Registered
Joined
·
461 Posts
Not a 100% sure proof method of checking the modulator, but run it hard up to the legal speed limit (not in a school zone) and then let off and coast, smoke may come out of the exhaust. Could be valve guides or rotted hoses to the modulator or the modulator itself.
 

·
Registered
Joined
·
934 Posts
Just pull off the line and check for transmission fluid. There should be none.

I had this same problem recently on my truck and #8 kept on fouling out. I also went through alot of trans fluid.

------------------
Bob (Pa.)

1963 Impala 283
1966 Chevelle SS 409
1969 Malibu 307
1972 Malibu 307
1969 Chevy stepside 350

Check out my website:
Bobs 409 Chevy Page

Looking for Chevelle or Impala parts? Click here:
Chevelle parts for sale
 

·
Registered
Joined
·
4,548 Posts
<BLOCKQUOTE>quote:</font><HR>Originally posted by cperrell:


Would more fluid leak out the modulator at high speeds?
<HR></BLOCKQUOTE>
It could but only up to a point.
<BLOCKQUOTE>quote:</font><HR>Originally posted by cperrell:
What about the vapor/smoke comming out of the crankcase vent? Is this a sure sign of the rings being shot? If the rings are OK, what else could cause the smoke?
<HR></BLOCKQUOTE>
This is normal,caused by a buildup of presure in the crankcase. The PVC valve removes this presure.

------------------
Undee's70SS

[This message has been edited by undee70ss (edited 06-05-2001).]
 

·
Registered
Joined
·
659 Posts
Discussion Starter · #8 ·
I sure hope a bad modulator is the cause of my problems.

How hard is it to change the modulator? I will be out of town this weekend and am thinking about trying to tackle it one day after work. I don't want to get it torn apart and find it is a multi-day job.

Also, how hard is it to find a powerglide modulator? Can I get it at the local autoparts store or do I have to go mail order?

Thanks,


------------------
Charles Perrell
[email protected]
65 malibu SS Convertible
283 2v powerglide
 
1 - 8 of 8 Posts
Status
Not open for further replies.
Top