Rob L Posted June 10, 2015 Share Posted June 10, 2015 (edited) Ok so I have a 74 260z L6 motor that when I go to start it ..it will turn over for a bit then just a clunk sound and nothing.....then I will try to start it again it will turn over but not start ...then I will try starting it again and it turns over for second then big clunk sound and stops turning over even though I got the key still turned on.So at first I thought maybe the starter was missing teeth so I replaced it .Car is getting fuel ...and has spark all plugs are new . It was running last week no problem before I took the carb off ...4 barrel Holley is back on and car is getting fuel but no start .I'm going to throw a wrench on the crank and see if I can turn it over by hand ....to see if its a huge internal problem .But I doubt it because it's made that sound before but has still started and run .Just thought I would post first to see if anybody has ran into this problem beforeThe sound is definitely coming from the back of the motor where the tranny meets motor.Just had the transmission off actually to replace the rear main seal so if the flywheel was wonky or loose I'm sure my guy would have noticed but who knows .Thanks for any replies Heres video of the start up..... http://vid1294.photobucket.com/albums/b606/theatriks/Mobile%20Uploads/trim.8F923CC8-F5DA-4D87-BA0B-114C55EE37AB_zps9tluipfu.mp4 Edited June 10, 2015 by theatriks Quote Link to comment Share on other sites More sharing options...
Miles Posted June 10, 2015 Share Posted June 10, 2015 Too much background noise and not enough of the "problem sounds". Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 10, 2015 Author Share Posted June 10, 2015 i just noticed that ....im going to take a better video tommorow ......but to clear it up more its as if the motor just stops mid turn......im thinking im going to replace all battery cables and starter cables as they may be suspect as well.... Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 10, 2015 Share Posted June 10, 2015 Put a meter on the wire to the starter solenoid and see what voltage does. If it goes to zero, you've lost power to the solenoid probably back at the switch, If it drops to around 11 and stays there after the engine stops, something locked up. The starter's still pushing, just can't get it done. If it starts at 11 then drops to 6 or some other very low number, you have a bad battery. They can show good voltage but fail when they are loaded. I just went through that, even swapped in a spare starter I had. Then I put a meter on the battery and saw it drop to 6 volts after a few cranks. Quote Link to comment Share on other sites More sharing options...
Enzo250gto Posted June 11, 2015 Share Posted June 11, 2015 Hi, Check the radiator water level. Take the spark plugs out and try again. If you have a leaking head gasket with water in the cylinder it will stop the engine from turning and can crack the bore as water won't compress. Hope that this is not the case. David Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 11, 2015 Author Share Posted June 11, 2015 I hope its not that either LOL!!!......now the car was running last week so hopefully its not that . This problem seem to get worse and worse and now just does it on almost every startup. Im going to test NEWZEDs reccomendation today at some point ...i even have a brand new battery i might throw on just to see if thats the case and if not at least i can rule it out. But i will check the rad just in case and any other things that might be recommended. I just want to drive it already !!LOL Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 11, 2015 Author Share Posted June 11, 2015 Ok so I put a new battery on and it is cranking strong ...not stopping mid turn which is good ...BUT still not starting UGH!!! So i decided to check my oil ..and the only reason i did this because i had a bad throttle plate gasket leak on my carb last week and when i pulled it off i noticed a puddle of gas sitting in the intake .....so that got me thinking to check the oil to see if any gas got in it and let me tell you i think a couple liters of gas got dumped in there because oil level is way high (just did an oil change not too long ago)...so im going to drain everything and refill again. But my question now is ...can an engine not start with all that gas in the oil ( i know not to run it if i get it started ).....keep in mind im getting spark and plugs are not fouled there brand new ...and after all those starting attempts past couple days ..plugs are still pearly white and not fuel soaked. Im at a loss now ... Quote Link to comment Share on other sites More sharing options...
beermanpete Posted June 13, 2015 Share Posted June 13, 2015 Yes, the engine will run with gas in the oil but not for long if it packs a bearing due to lack of lubrication. It is likely a cylinder had enough fuel in it from your fuel leak that it hydraulic locked. You should pulls plugs and pump out any fuel that might still be in the cylinders. Be sure to disable the ignition fisrt to prevent a fire. Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 13, 2015 Author Share Posted June 13, 2015 That's for the reply beerman Pete ! I will definitely give that a try . Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 14, 2015 Author Share Posted June 14, 2015 (edited) OK so i have tried everything you guys have mentioned and still nothing ...exact same problem from the original post ..went to start and it stopped mid turn and stopped so hard and suddenly that the prop rod flew out. Everything I have done so far to try and find out what the problem is: -Brand new battery -brand new starter -brand new plugs -new wires (have not installed yet. Was still getting spark...installing soon) -drained oil ....there was a bit of gas in there but got it all out. -4 fresh liters of oil and new filter - repaired holley 4 barrel throttle plate gasket leak...no leaks now and car is getting fuel ...i can smell it and see it going in the intake -fuel pressure 3psi Now i have a new cap and rotor which i still need to install. While i was doing the oil change, i took the plugs out and they all looked good still pearly white. -after oil change installed plugs and when to start the car .....very first shot it almost sounded like it was going to start but that went away immediately. -cranked on her again and was turning over strong ....then kept trying ....only tapped the gas pedal real quick twice while trying to restart the whole time no way i could have flooded her. -then my last attempt is how i described it in the first post and in this post..... the mid turn stop and clunk sound. So this has stopped me dead in my tracks again ....but i wont given up LOL !!! Last thing now that has me convinced i have gremlins in the car is i had a new accel coil... so i figured what the hay i will give it a try and replace that to see what happens ......well i installed the new one and the phillips screw that holds the coil tight is stripped now and has lost its clamping force ..but not a huge issue....go to start the car and now nothing not even a click dead silence when i turn the key ......So i figured the logical thing is to put the old coil back because the car was just turning over and fuel pump was working with it so everything should be fine. Well now with the old coil back in and it was just working 5 minutes ago ....it too is not working now .... i turn key and nothing happens and battery is not dead......This is where i closed the hood and am now enjoying a beer so i dont lose my mind lol Let me know what you think.... Edited June 14, 2015 by theatriks Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 14, 2015 Share Posted June 14, 2015 (edited) What you described initially is also somewhat typical of having ignition timing too advanced. Have you checked timing? Could be that your breaker plate is stuck advanced, or sticking occasionally. It starts when it frees up, doesn't when it's stuck. The breaker plate moves for vacuum advance. On the dead engine after the coil swap - where's the meter? Super simple to check for coil power, solenoid power, starter cable power, etc. You're not doing the basics of problem solving. You can even do the meter checks with a beer in hand. Edited June 14, 2015 by NewZed Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 14, 2015 Author Share Posted June 14, 2015 Ok I hear ya ...I do have a meter ...I wil get all points checked with it . Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 15, 2015 Share Posted June 15, 2015 It's hydro-locking, except with gas instead of water. Pull the plugs out, the cylinders are probably filled with gas. What There must be a leak somewhere in the carbs and gas is flowing into the cylinders. Are they they the stock flat top carbs? Check you oil, it probably has a lot of gas in it. Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 15, 2015 Author Share Posted June 15, 2015 Ya I did all of that and yes I had a bad carb leak it's a Holley 4 barrel with Clifford intake and yes there was tons of gas in the oil . Unfortunately I have emptied all of that and filled it with a fresh 4 liters and still no start Tommorow night I'm gonna check all the points with a meter and go from there Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 16, 2015 Share Posted June 16, 2015 153624 advanced timing, crossed wires will do that. Along with hydro locking which exacerbates it! Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 17, 2015 Author Share Posted June 17, 2015 So I put a meter on the 2 ignition coils I have ...there both good . My brother in law came by and put a test light on my starter and it was lighting up ...he even put the test light on my head and intake and it was lighting up too !! We were both baffled and he thought my new starter might be suspect ....so I pop the old working starter back in....and the test light didn't light up off the block or intake anymore lol ....but still no power. At one point I went to turn the key and heard the fuel pump going so I figured I got power back but once I tried to start it just went dead again and I tried again to start and it just stayed dead ...nothing . Going to check the fuse box next ...hoping nothing is melted together . Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 17, 2015 Share Posted June 17, 2015 What you wanted to do was check for power to the coil with the key on. You're not getting much value from the meter if you only checked resistance on two coils. Looking back on the complete saga, it wouldn't be a surprise to find that you just have dirty/corroded battery cable connections. Quote Link to comment Share on other sites More sharing options...
Rob L Posted June 17, 2015 Author Share Posted June 17, 2015 Lol I know it's turned into quite the ordeal ...I got a Ron Francis battery cable kit on its way .I was trying to tell my brother in law that we needed to check the ignition coil .....he's a mechanic and stubborn and was convinced that the problem lied with the starter. I will try what you just suggested next as well. Quote Link to comment Share on other sites More sharing options...
beermanpete Posted June 17, 2015 Share Posted June 17, 2015 It sounds like you have multiple problems. First, check the carb for fuel leaks down the manifold. You should not see any fuel discharge while cranking (except for the accelorator pump momentarily when you open the throttle. The float level may too high, bad float valve, etc. Hollys have, or had, a bad habit of blowing the power valve on backfire that can cause problems. Check that too. Second, get it to crank reliabley. Not start, just crank. Take out the plugs, disable the ignition and crank the thing to blow any fuel out of the cylinders.Once you know it cranks reliably, if it stops mid-crank you will know it from the ignition trying to fire at the wrong time and can concentrate your efforts there. Third, diagnose any ignition problems. Firing order, timing, primary wiring, and so on. Be methodical and check each system one by one. You will waste a lot of time jumping around playing whack-a-mole otherwise. Quote Link to comment Share on other sites More sharing options...
duragg Posted June 17, 2015 Share Posted June 17, 2015 Mine locks while cranking like that sometimes. You have a stock flywheel? I have an aftermarket Aluminim flywheel and I don't think the teeth are beveled like stock and they jam occasionally. May try to loosen starter and reposition it just slightly. Quote Link to comment Share on other sites More sharing options...
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