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Bent valve?


Scrapson

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It’s new carb that’s why the idle solonoid wasn’t hooked up I’ve had the carb for 3 days but yes that’s understandable next time more pictures and the details should be more in depth. The battery is shot the battery is also too old to return by like 2 months so that’s cool too and they tested it they said it’s fine but if I don’t drive my pickup for a week the battery goes dead even when I pull it out and set it somewhere that’s not ground. So I’m not really sure what it is but I’m going to go pickup and nice optima battery since those things last forever. 

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Do some homework on Optima batteries. They USED to last for a long time but I think you'll find that they don't any longer. Just like fram, they USED to be good filters but they are cheaply made in China with the cheapest parts now. I only use a fram to cover the oil filter boss when spray painting an engine block.

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Interesting I’ve heard nothing but good things for the optima gel batteries from my buddies dad he used them in his rally 510’s that he stores for winter then after that he throws them on the charger and there still going good after 4 years.FRAM filters yes I’ve heard mixed things about them that’s what my pickup used to have but now it’s just a regular car quest filter. 

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alright I like the cheaper option for this one. I’ll get the carb shit hooked up and firing it up hopefully today is the day scrapson runs again if not I’m gonna shit a brick and buy an L16. Or a diesel motor for it since I found one for $200 and take it to a shop to have it rebuilt and shit

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This is almost 10 pages of you running off on a tangent. Bent valve?, head removed, timing chain tensioner fell out, no spark, random carb change......  How will you get another engine working when this one can't be finished.  Make a plan and stick to it till completed. Fix only what's not working..

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Yeah I noticed that when I found a problem I did that one too then another one but to be fair with the timing chain one the tensioner wasn’t even where it was supposed to be before I even took off the cam sprocket. Now I know this and I can tackle the problem on my own to a point besides the carb. 

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Yes, focus is important. It is possible to broaden your focus to include things in the same system, like fuel system, or brake system, etc. If you're working on the carb, it may make sense to replace the fuel filter, the hoses, blow out the lines, clean the tank and check the pump. After that is accomplished, you can now say that the entire fuel system has been checked off the list.

 

Work in systems. It's easier to keep track of things that way.

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At this point we have the idle solonoid hooked up but it just runs away. We can get it to idle but as soon as you try to give it throttle it runs away and I don’t know why it seems like there’s too much fuel but the air fuel screw is at a turn and half the timing is right. 

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So many little things can cause it to run away like that, but it's most likely carburetor linkage related. Do you have a return spring? Have you looked down the barrels to see if they are closing all the way? If the choke isn't adjusted properly it can affect the idle.

 

Two other things - timing and vacuum leaks. If the timing is too advanced that can cause it to idle high. If there is a tiny vacuum leak anywhere, combine that with the timing and linkage or choke adjustment, that could be it too. I know you said there are no vacuum leaks, but check again. Check by making sure the carb is tight and the adapter plate too.

 

Set your timing with a light, not by ear. And did you say you checked your TDC marks earlier in this thread?

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What do you mean by runs away?  It wont return to idle?  From that pic on the page before, the idle return spring looks way to tight and almost like it will bind on the side of the carb.  To much tension will wear the shit outta it as well.  Also, are all the vacuum leaks plugged?  Does this carb have a spot at the base to hook up the vacuum advance?  I cant tell if you have the line coming off the intake plugged or just running open under the rad hose.

 

 

 

 

 

Edited by bilzbobaggins
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Yeah I have checked my TDC 3 times now. We found a vacuum leak in the spot I didn’t even check the block plate was bowing so it just sucked air in so bad. My buddy is going to go make a new one since the one I made it too clapped so just waiting on that. It’s at 10° of advance right now any other places for vacuum leaks I can’t find any ideas. I checked the intake manifold it’s good and aswell as the brake booster line is plugged for now. The VA line to the carb is plugged since I decided to re route it to the manifold. I know the sprint is wack I had to do that till I got a new sprint since that one was not closing it back to idle all the way it was a little too big. 

Edited by Scrapson
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Bet that was the EGR block off plate. Something that was an added problem when it didn't need to be. It's far easier to just disconnect it to disable it. Tell the truth the EGR has little effect on performance anyway. It only works during part throttle. That vacuum leak probably led to you buying a new carburetor... that may not have been need it 

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Yeah the block off plate was a bit of added problem. However pulling off the EGR is so nice I can get to the bolts on the intake manifold so much easier. Perhaps but it was a free carburetor so I can’t complain there much. That’s the only spot I can find a vacuum leak that’s on the intake manifold the carb is on there good the VA line is plugged there since I rerouted it at this point I’m thinking it’s just that and I scheduled to have a mechanic go over everything before I try anything else I just want the datsun back. 
 

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The way the vacuum advance works is when idling the butterfly closes below the vacuum advance port/hole in the carb which means the vacuum line has no vacuum therefore it idles at whatever you have the timing set at, but the moment you touch the pedal and open the butterfly it sees a little vacuum and advances the distributor a little, the more pedal you give it the more advance it sees as there is a lot of vacuum right there, once the RPMs are up the mechanical advance kicks in and it advances even more for higher RPMs.

 

Having the distributor vacuum line connected to the manifold will screw things up, modern distributors are not made to work that way, it will see a lot of vacuum at an idle when it supposed to have hardly any vacuum, one likely could get it to start when floored but the moment you let off the pedal I just don't see it running properly.

 

Before you even try to start it you need to plug any vacuum leaks in the intake manifold, if there is a hole where the EGR was you need to make a plate to cover it, you should have no vacuum leaks of any kind in the intake manifold if you want it to run properly.

 

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