bob3d Posted August 16, 2019 Report Share Posted August 16, 2019 Can loose timing chain cause this? Nothing loose in diff or driveshaft. New clutch. New dist and coil. New carb. Any ideas? ? Quote Link to comment
Crashtd420 Posted August 16, 2019 Report Share Posted August 16, 2019 Well 2 things come to my mind.... Was it just a new clutch or was the flywheel replaced and or checked? If the fly wheel has high and low spots it could be grabbing weird..... But more than likely its the carburator , did you just bolt it on? What type of carburetor? And on what motor? It may not be properly set up for your application.... Quote Link to comment
banzai510(hainz) Posted August 16, 2019 Report Share Posted August 16, 2019 (edited) make it more clear. Acelleration while the clutch is coming out or just starting from a rolling slow to speeding up by just pushing on the pedal.? Whats the timming ? accel pump on carb good? But you say new carb also. So really it should be good If it was a clutch then you would have had the proplem ealier before the new clutch. Most time the clutch slips if flywheel needs to be turned. Edited August 16, 2019 by banzai510(hainz) Quote Link to comment
bilzbobaggins Posted August 16, 2019 Report Share Posted August 16, 2019 Was it doing this before all the new parts were installed? Quote Link to comment
datzenmike Posted August 16, 2019 Report Share Posted August 16, 2019 If this happens after flooring the gas and accelerating HARD in first or maybe into 2nd.... replace the fuel filter. Quote Link to comment
bob3d Posted August 16, 2019 Author Report Share Posted August 16, 2019 (edited) Did it before replacing parts. Could be flywheel but clutch was done by a place I use that only works on Datsuns so I trusted them. Clutch seems fine. This car was bought new by my mother so it has not been messed with except by me. It has 100,000 miles. The head was serviced by a head shop and was decked but don't know how much. I had this problem when I got the car. Driveshaft is new and old one was good. I've been working on my cars for 50 years so I'm not a beginner. Any of your ideas are appreciated and I'll let you know if yours works. Thanks. By the way it does it on gentle and normal accel and the replacement carb was an exact replacement from National Carburetors and I must say the quality was impressive. The motor is A14. I will say my mother would not downshift until the car started shaking. Edited August 16, 2019 by bob3d Answer specific questions Quote Link to comment
datzenmike Posted August 16, 2019 Report Share Posted August 16, 2019 Flywheels do not cause 'jerkyness'. If anything they smooth out engine operation. Jerkyness.... on and off power? like turning the ignition on and off while driving?? Does this pretty much describe it??? Quote Link to comment
bob3d Posted August 16, 2019 Author Report Share Posted August 16, 2019 (edited) It's not real bad but it's not right. I will go drive it to see if it happens when coasting. I don't think it does but I'll check. I would hate to risk turning motor off and on while driving. Thanks Mike. Ok I drove around. Problem mainly at low speed under 10 mph. Not when coasting. Otherwise car runs great. I'll get to the solution one day. Edited August 16, 2019 by bob3d New info Quote Link to comment
datzenmike Posted August 16, 2019 Report Share Posted August 16, 2019 Wasn't suggesting you turn engine off and on. I said like that. Rather abrupt on and of power. Quote Link to comment
bob3d Posted August 16, 2019 Author Report Share Posted August 16, 2019 Sudden power increase causes no jerkiness. Quote Link to comment
Tom1200 Posted August 16, 2019 Report Share Posted August 16, 2019 Under 10 mph I will assume this is in first gear; what RPM and what throttle setting? 1200 rpms 1/2 throttle etc.? We'll need to no exact conditions to tune it via the internet. It could be excessive drivetrain lash, something like a severely worn ring and pinion but that would likely do it at other speeds to some degree. Go through this methodically; with the clutch fully engaged at 5 mph try gently rolling into the throttle, repeat this process but roll into the throttle more quickly each time. Next what kind of shape are the dampers/shocks in, if they are sacked it might make the car feel jerky. As someone who has owned and A-series powered car for 35 years I can tell you they like revs when you take off, they don't particularly like it if you trying to roll off a light with less than 2000rpm. Quote Link to comment
bob3d Posted August 16, 2019 Author Report Share Posted August 16, 2019 Struts and shocks new. Could be ring and pinion but at 100,000 miles? There IS a very slight whine. Changed diff oil. No metal on magnetic plug. Never will find a good diff. Trans oil never been changed, 4speed. But it's full. Quote Link to comment
datzenmike Posted August 17, 2019 Report Share Posted August 17, 2019 Lets narrow this down. Are you saying that you are idling along in gear, foot OFF the clutch, probably in first gear and you add gas and the car shakes? Quote Link to comment
bob3d Posted August 17, 2019 Author Report Share Posted August 17, 2019 What you say is true. I have removed the high sensor. on the trans. Been all o ver this car for 10 years. I will recheck the timing since the head was decked. Currenly 10 dg btdc. Quote Link to comment
datzenmike Posted August 17, 2019 Report Share Posted August 17, 2019 2 hours ago, datzenmike said: Lets narrow this down. Are you saying that you are idling along in gear, foot OFF the clutch, probably in first gear and you add gas and the car shakes? 31 minutes ago, bob3d said: What you say is true. Once the engine begins to accelerate the car, all the drive train slack is taken up. So not the flywheel, clutch, drive shaft or differential. There is no carrier bearing on the B-210 so not that either. I would begin by looking at the engine to transmission bolts, are they all there and tight? Are the rubber engine and transmission mounts broken or loose? You may have to pry on the engine with a piece of 2x4 to move it enough to see. Then the leaf springs. Are any leaves broken or missing or mounts and U bolts loose? What about the shock absorbers? Are they worn out and soft? Quote Link to comment
bob3d Posted August 17, 2019 Author Report Share Posted August 17, 2019 Not a shake but more of a lurch. New shocks and struts. I will look at the leaf springs and trans bolts. The motor mounts are good. I once had a similar problem on another car caused by carb linkage but the pedal does not bounce. I am changing the trans oil today with GL5 90wt. Will let you know later. Thanks Quote Link to comment
Stoffregen Motorsports Posted August 17, 2019 Report Share Posted August 17, 2019 How about the u-bolts? If they are loose, your pinion angle will change under accel/decel causing a vibration. Doesn't sound like your problem though. Is the car lowered? I suspect it's a driveline related issue. Improper angles, bad joints, bad trans mount, loose or worn out axle locating hardware, etc. Quote Link to comment
bob3d Posted August 17, 2019 Author Report Share Posted August 17, 2019 (edited) I just changed the trans oil just to get it off my mind, gl5 80-90 wt. I will check all you said tomorrow but a visual showed nothing obvious . Car is not lowered,very original except for the decked head. Edited August 17, 2019 by bob3d Answer specific questions Quote Link to comment
banzai510(hainz) Posted August 17, 2019 Report Share Posted August 17, 2019 changed the left turn signal bulb. OK just joking Quote Link to comment
bob3d Posted August 17, 2019 Author Report Share Posted August 17, 2019 Front or back? Quote Link to comment
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