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Need help getting rebuilt sb to start.
Hello,
Have you ever had one of those days when nothing seems to go right? Anyway, I had one of those days today with trying to get my chevy 350 started after dropping it in my 71 camaro. I just spent the last 8 months rebuilding it from the main bearings to the carburetor. First, I would like someone to verify that I indexed the distrbutor right, and that I have the rotor in the right position because I think that is where my problem is. Before I put the motor in this morning I had rotated the engine by hand until number one cylinder was at top dead center. I verified this by pulling the plugs out and feeling the compression coming out of the number one spark plug hole and also gently putting a screwdriver in the hole to verify that the piston was all the way at the top of its stroke. Now, going over to the distributor, I positioned the rotor at the 1 oclock position. I did this by pulling the distributor out of the hole in the intake manifold until it was disingaged from the camshaft gear/oil pump shaft, rotating it 180 degrees, reinserting it back down in the hole, and checking the position of the rotor. I did this procedure until I got the rotor at the 1 oclock position. Now, correct me if I am wrong, but if I am sitting on the roof of my car facing the front of my car, the one o clock position on the distributor(the corresponding spark plug wire in which goes to the number one spark plug in number one cylinder) is that terminal post on the distributor cap that is located at the top right hand corner of the cap. Then going in a clockwise direction the next terminal post on the disbributor is at about the 2 oclock postion, and its corresponding plug wire goes to the number 8 plug, then continuing in the clockwise direction, the rest of the firing order sequence is 4, 3,6,5,7,2. I put the motor in today, hooked all the wires back up,starter, battery, voltage regulator,etc. and tried to start it, but I got nothing. It was turning over, that is to say, the crank was rotating, but it was not starting. It is getting gas, there is plenty of fuel in my new see through fuel filter before going into the carburetor. However, I pulled the number one plug wire off of the the top of the distributor, held it as close as I could to the disbributor cap post with insulated pliers, and then had my brother turn the motor over while I checked to see if I was getting any spark from the number one plug wire to the number one terminal post on the distributor cap. I did not see any spark. So, I don't think I am getting any spark to the plugs. The distributor is a brand new unit from summit. Its an HEI unit that I just got last week from summit. It cost me about $100. It have an adjustable advance unit that can be adjusted by inserting a 3/32nd allen wrence inside the vacuum advance unit. Anyway, back to my problem. I disconnected the wiring harness that goes to the BAT Tach position in the distributor cap and measured 11. 59 volts at the contact in the wiring harness that goes to the BATT connection in the disbributor. So, that is my dillema. Can anyone offer any suggestions. I can't wait to hear this thing start with all the work that I have put it to it. Also, do I have to have a stand alone wire going fron the engine block to the the frame? Rob. |
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Sounds like you have it 180 out. I believe the rotor for firing on the number 1 cylinder is supposed to be near the 6 o' clock position pointing somewhat towards the front of the motor. But there might be more than this since you don't appear to have spark but try dropping in the dizzy again and see what happens. Your firing order's correct and just to be sure if you really are on true tdc and not the exhaust stroke, pull the right valve cover off (driver's side, there you happy xntrik??
Last edited by Classix_Lover; 07-03-2006 at 09:23 PM. |
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spark ?
is the spark blue ? = strong
if you built this. you are competent enough to understand whats going on , identify the problem, and make the repair. pep talk over. low voltage will cause it to behave in that manner. you cold timmed it do you really think its 180 out ? flip it real quick. put her on TDC ((feel with a straw or what ever) or before), have the rotor pointing toward the 1 terminal in the cap(or just before), lite her up. no 12volts, huh. is it externally regulated ? is it sourced to the battery + ? i believe you field wires should have 12+ volts while running. usually this is where ignitions tap for power. check a diagram and make sure. always watch for fuel leaks in new builds. can lead to fire, smoke, screaming, and running. |
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dont forget this either while setting timming
it sounds retarded
dont forget to compensate for intial timming advance happening in the intial timming curve area. most distributors mechanically add 2-3 degrees starting around 900 rpm. you set it for 14 at 900 but really have only 11... blam your retarded... just like that also dont forget to compensate for mechanical retard that happens in distributor gear drive systems. the timming chain (best for this), shaft , gear teeth, all effect timming under load. ever wonder why that MSD bushing thats says 21deg is only giving 20.? i did. most people dont think about it and just adjust there curve according. those who play the numbers only get bit hard. those who dont keep track of there numbers also get bit pretty good. **this post goes to another thread*** oops. Last edited by spinn; 07-03-2006 at 10:11 PM. Reason: this is the wrong reply in wrong thread |
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mouseman,
Check the ground wire that goes to the distributor. No ground equals no spark at the plugs. But the other thing to check, and it sounds like I am making fun of you, BUT I AM NOT, is the rotor inside the cap? I have done this myself and I saw the guys on the Coddington show do it too. No rotor no spark at the spark plugs. Scholman |
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You prolly wouldn't get spark from the cap terminal to the wire cause there is no direct path to ground through the plug.
Pull the #1 plug then plug it back into the wire and hold the plugs threads to a good ground and see if the plug is sparking. Another problem could also be your ground strap if you don't have one and your useing stock rubber motor mounts the motor might not be grounded so the plug can't spark. Evan with the distributor waaaaaaaaaaaaaaaaaaayyyyyyyyyyyyyyy off time the engine should still try to fire and pop out the exhuast or carb.............or like usually w/ me burp a fireball out the carb and blow the power valve in the carb LOL
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Doc here,
The EXACT reason your not getting fire while cranking I'll just bet... sounds like You did not hook up the secondary Ignition..This is power to the HEI during Crank modes when the key slips from "Hot in Run" to "START" and cuts power to the whole car..This wire runs from the "R" or "I" terminal on the starter solenoid and parallels into the "BATT" wire on the HEI.. If you had a points type ignition in there before , be sure you removed the resistor or resistance wire..this will drop Loaded power down to 6 to 9 volts and if it runs...It will run like "Crap in a Can".. To test on an in-op Secondary ignition...Run a jumper wire DIRECTLY from the + terminal of the battery to the HEI "Batt" terminal and crank it over..If it fires and runs..you need the secondary ignition..And ...BTW..you'll need to remove the jumper to shut it off...your ignition is bypassed. Traditionally, The #1 plug tower on an SBC, is 5 to 7 O'clock (as your facing it looking from front down..) 12 O'Clock is firewall and 6 O'clock is Fan.. HOWEVER..you may index #1 any spot on the clock you want..(For instance you may need clearance for an Advance unit..) But If clearance IS not a problem, I'd stick with 5 to 7..FOR the sanity of the next wrench to tune the car..If not..at the very least print out the new location and F.O on a 5 x 7 card..laminate it and glue it to the hood next to the spec decal.. Try the jumper to the HEI, and post back the findings..If that does not cure the problem we can assist in further "NO SPARK " troubleshooting.. Happy 4 th Of July! Hotrodders are the Most independent group of individuals today.. So I guess It's our Day too... Doc
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Aftermarket Solutions Electronic & Electrical Innovations |
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Thanks for all the things to check. The EXACT part number of the distributor that I put in is SUM-850001R, I did not adjust anything other than putting the rotor at exactly the 1 oclock position as seen looking forward, that is, 12 oclock fan, 6 oclock firewall. I have another problem though, the key in the ignition switch is stuck in the start position, so I have to order another one, switch that is. Can I still run a jumper from the positive of the battery terminal to the BATT connection on the distributor cap? How can I get it to start without the switch unless I jump from the solenoid to the starter.
I disconnected the ground on the battery of keep it from discharging. Also, the coil is internal of the distributor/on top of the distributor. Thanks, Rob |
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As Doc said, did you convert to HEI? If you did, you need a new, keyed power 12 volt source to the distributor...
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later model GM's had a duel contact switch to do away with the secondary ignition, and no resistance wire / Resistor. Hence, When converting to HEI, or installing a later model engine on an older body vehicle, requires the need for a secondary Ignition source, and removal of the resistance wire / resistor.. The secondary ignition source is commonly run from the "R" or "I" terminal of the Starter solenoid, to the BATT or primary side of the coil.. If you have upgraded to a mini starter, that does not have the provision for the "R" terminal, you can run a relay, that gets power from the "S" terminal, and provides direct battery voltage to the coil primary. Happy 4 th Of July! Hotrodders are the Most independent group of individuals today.. So I guess It's our Day too... Doc
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Aftermarket Solutions Electronic & Electrical Innovations Last edited by docvette; 07-04-2006 at 04:45 PM. Reason: I Befor E...Except after a 12 pack... |
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Doc here, I hear ya.. Surprising how many guys Forget, or Don't even know that a secondary Ignition is used on older vehicles..(Until, the wire falls off and it won't start anymore... or they upgrade to HEI on a single contact "Hot in Start" Ignition (old style ) Switch.. )Happy 4 th Of July! Hotrodders are the Most independent group of individuals today.. So I guess It's our Day too... Doc
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Aftermarket Solutions Electronic & Electrical Innovations |
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Ok, good news. I ran a jumper from the positive of the battery to the BATT connector on the distributor, grounded the engine to the frame, and then used a screwdriver to jump across the starter to the solenoid. Remember, my ignition switch is broken. I have one on order. In any event I have spark at this point; however, If the motor does not start, should I move the distributor a little clockwise or counterclockwise around the 1 oclock postion to help it start. As a reminder, I made sure that the number 1 piston was at top dead center of the compression stroke and my rotor button was exactly at the 1 oclock postion before I started this process.
rob aka mouseman |
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I got ya, Doc. My bad, hope I didn't confuse the issue. I was reading "primary, secondary" and thinking only of the coil, forgetting that the ballast bypass was also called a secondary ingnition feed.
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Is this correct? Last edited by sbchevfreak; 07-07-2006 at 07:14 PM. Reason: re read doc's post |
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