ronnie27 Posted August 1, 2016 Share Posted August 1, 2016 Hi guy's, first time to post. Have been a member now for about 9 months. 64 Riviera, white. I have been reading this forum for around three years and have learned a lot, Thanks! With that said; now my question, it seems that my car has slowly been loading the engine down more and more when I first shift from park to reverse or drive. It seems to pull the rpm's down almost 400 rpm's requiring me to slowly have been increasing the idle speed to keep from stalling. The engine is strong, burns no oil, no smoke, etc. Haven't run a compression check but don't feel the need by all other symptoms. No vacuum leaks can be found. Timing is dead on. Vacuum modulator seems to work fine as far as shifting goes, (have tried running with it disconnected, definitely changes things). The engine was supposedly rebuilt around 20,000 miles ago. Had a carburetor on until recently. I now have a FiTech throttle body fuel injection installed. It can correct for the above issues to some extent but still have the root problem. Suggestions please. Link to comment Share on other sites More sharing options...
JZRIV Posted August 2, 2016 Share Posted August 2, 2016 Welcome to the forum Ronnie. Was the problem evident prior to installing fuel injection? Link to comment Share on other sites More sharing options...
1965rivgs Posted August 2, 2016 Share Posted August 2, 2016 Vacuum leak and/or fuel mixture at idle speed Tom Link to comment Share on other sites More sharing options...
ronnie27 Posted August 2, 2016 Author Share Posted August 2, 2016 To respond to above, yes the problem seems to have been developing over a long period, and definitely before the FI was installed. The fuel/air ratio runs between 13.5 and 14 according to the programmer included with the FI unit. I totally agree with the vacuum theory but I can't locate any, I have actually replaced all the hoses. Distributor vacuum advance possibly or Vacuum modulator possibly? Distributor worn out, I don't know. Just a little extra info, once I'm rolling it runs and shifts fantastic. Link to comment Share on other sites More sharing options...
ronnie27 Posted August 2, 2016 Author Share Posted August 2, 2016 Oh, by the way, nice to meet you both and thanks for the quick replies. Link to comment Share on other sites More sharing options...
JZRIV Posted August 2, 2016 Share Posted August 2, 2016 Have you checked manifold vacuum with a vacuum gauge? Link to comment Share on other sites More sharing options...
ronnie27 Posted August 2, 2016 Author Share Posted August 2, 2016 Manifold pressure, 15 in with a slight upward waver toward 15.5 at 800 to 850 rpm's. "IF" the engine is not the problem, is their anything in the transmission making it begin to pull sooner than normally expected, say 600 rpm. Link to comment Share on other sites More sharing options...
1965rivgs Posted August 2, 2016 Share Posted August 2, 2016 Your intake manifold vacuum level at idle, 650 RPM, should be at least 18 inches with a stock cam. Is it possible the balancer has "spun" and your timing marks are no longer valid. Try advancing the timing until you detect some spark knock and back off a little. Tom Link to comment Share on other sites More sharing options...
ronnie27 Posted August 3, 2016 Author Share Posted August 3, 2016 Will try and check that tomorrow. Thanks Link to comment Share on other sites More sharing options...
ronnie27 Posted August 3, 2016 Author Share Posted August 3, 2016 Well guys here is where we are at. Since I'm about 2db from deft I advanced the timing to around 9deg. The car is running at around 650 to 700 rpm's. It shifts much smoother at the lower rpm's and doesn't tend to stall near as bad. When I hook the vacuum back to the distributor the advance moves to I'm guessing (no timing marks) to approximately 20 degree's at idle. The vacuum pressure is around 13 at this point. Let me also say I am getting this number from the F.I. controller since I don't own a vacuum gauge, can't vouch for the accuracy. Additionally as originally stated the engine was supposedly rebuilt so I also can't vouch for the originally of the cam. Unless you tell me I'm damaging something I am going to try it for a while and see what happens. Since you mentioned that possibly the balancer had moved I assume it is not keyed, is that correct? Everything seems tight and runs true. I did have a three groove balancer pulley on a big block Chevy come apart a few years ago on Hot Rod Power Tour. Thanks to three guys from Minnesota and a couple of local hot rodders I was back up and running in a couple of hours, free of charge. Thanks for all your help. Link to comment Share on other sites More sharing options...
JZRIV Posted August 3, 2016 Share Posted August 3, 2016 You need to purchase or borrow a vacuum gauge Ronnie. Besides a simple vacuum reading, a vacuum gauge can help you determine the engines condition. The dampener/balancer doesn't slip on the crankshaft. The outer portion of harmonic dampener (with timing mark) is attached to the inner portion with vulcanized rubber. If that rubber get old and becomes detached from the inner portion it can slip. Link to comment Share on other sites More sharing options...
RivNut Posted August 3, 2016 Share Posted August 3, 2016 The balancer is keyed. If the balancer did move, the outer ring has probably spun around the rubber insulator. Send it to the Damper Dude and have him check it out. http://www.damperdudes.net/ Ed Link to comment Share on other sites More sharing options...
ronnie27 Posted August 4, 2016 Author Share Posted August 4, 2016 Ok, now I understand where we r going with the inner and outer ring. Thanks. Likely will not get to this for a little while, fixing to head to the mountains for some vacation time. Link to comment Share on other sites More sharing options...
EmTee Posted August 4, 2016 Share Posted August 4, 2016 (edited) Perhaps a relatively quick check of the harmonic balancer would be to pull the #1 spark plug and insert a suitable tool, modified spark plug, or screwdriver (need two people for that) that will act as a positive stop for the piston as it rises in the cylinder. Slowly spin the crankshaft - *BY HAND* - CW until the piston stops, then mark the balancer location at the 0 deg/TDC reference point. Next, do the same thing CCW and mark again. If the TDC mark on the balancer is centered between the two marks that you made, then the outer ring hasn't slipped and timing should be accurate. Edited August 4, 2016 by EmTee added cautionary text (see edit history) Link to comment Share on other sites More sharing options...
ronnie27 Posted August 4, 2016 Author Share Posted August 4, 2016 EM TEE, I like this idea, but #1 is difficult to get to on an AC car. Wondering if you or someone knows which/if another piston is also at t.d.c. at the same time as #1, albeit not on the same stroke (power)? Link to comment Share on other sites More sharing options...
RivNut Posted August 4, 2016 Share Posted August 4, 2016 (edited) I've seen a product that you could use on the #1 cylinder with the a/c in place. It screws into the sparkplug hole and has a tube running from it to which a whistle is attached. As the piston approaches TDC, the sound coming from the whistle becomes more shrill. Type "spark plug whistle " into your Google search and you'll find them. You can also use a compression guage IF it also shows vacuum. Go to YouTube and type in "finding top dead center Eric the tool guy." His video will guide you through the process. Edited August 4, 2016 by RivNut (see edit history) Link to comment Share on other sites More sharing options...
EmTee Posted August 5, 2016 Share Posted August 5, 2016 (edited) If the firing order is 1-8-4-3-6-5-7-2, then the piston in cylinder #6 would be at the top of the exhaust stroke when #1 is at the top of the compression stroke. For any other firing order I believe that the same should be true for the fifth cylinder in the firing order (assuming 8 cylinder). I just checked and it seems the nailhead firing order is 1-2-7-8-4-5-6-3, so I believe you would use cylinder #4 as the alternate to #1. Edited August 5, 2016 by EmTee added information (see edit history) Link to comment Share on other sites More sharing options...
telriv Posted August 5, 2016 Share Posted August 5, 2016 Yes, cyl. #4 is the CORRECT cyl. Link to comment Share on other sites More sharing options...
ronnie27 Posted August 5, 2016 Author Share Posted August 5, 2016 Thank you, that will make things much easier. Will update on results when I get them. And I will be shopping for vacuum gauge, hopefully one that do the job and not break the bank. Link to comment Share on other sites More sharing options...
alini Posted August 8, 2016 Share Posted August 8, 2016 I would check the operation of your torque converter. I'm betting the switches on the throttle are not working or out of adjustment and your trans is loading up the engine too much. I am having similar issues with a major idle drop when put into gear and going down that path of troubleshooting. Link to comment Share on other sites More sharing options...
JZRIV Posted August 8, 2016 Share Posted August 8, 2016 The 64 did not have the variable pitch trans & converter. 65,66,67 were only year privileged to get this. Link to comment Share on other sites More sharing options...
alini Posted August 8, 2016 Share Posted August 8, 2016 3 minutes ago, JZRIV said: The 64 did not have the variable pitch trans & converter. 65,66,67 were only year privileged to get this. Missed that part of his post. Nevermind Link to comment Share on other sites More sharing options...
ronnie27 Posted August 8, 2016 Author Share Posted August 8, 2016 Thanks guys, I have verified the damper is fine. Moving the spark advance has helped a whole lot. I have located a vacuum gauge to borrow to get an accurate manifold reading, but haven't had time to go get it. I am going to have to pull off the car for a couple weeks. Will get back on it then. Thanks again for who have tried to help. Link to comment Share on other sites More sharing options...
EmTee Posted August 9, 2016 Share Posted August 9, 2016 That's good --sounds like you're making progress! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now