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Sounds crazy but who knows?

H

hippie

Regular Contributor
Today we attempted to start the motor we rebuilt last fall. It cranked over fine without any noises, however, it would not start. It is a 1988 Chevy 350, 260 hp, nothing special about it. All we could get was back firing and coughing thru the carb. When we assembled the motor I know we turned it till #1 cylinder was on compression and then put the distributer in so it was pointing at #1 cylinder. Obviously we have spark and fuel but yet something is not right. The timing chain was inspected and is not stretched and did not jump a tooth.

If anyone has a suggestion please post.

Thanking all in advance, Bob
 
That is what we were thinking. We may have been on the exhaust stroke. On Sunday we are going to work on it some more.

Thank you, Bob
 
There is usually a #1 on the cap,thats where the rotor points ,then clockwise 1,8,4,3,6,5,7,2
Regardless of where you set the rotor, verify #1 coming up on compression, rotate untill timing tab shows "0". see where rotor is pointing in the cap, use that post for #1 plug wire.
 
This might help you a little, Do as the Bt Doctur says but I find it helpful to mark where your dist rotor is pointing then rotate the cap until a post is in line with mark, That will be your # 1 and add rest in order called for..
 
The timing mark on the crank does past the timing pointer 2 times per cycle.

as mentioned, could be 180 out (were you looking at the 1st rocker? exh. ) when thinking of where you were?

else, yea.. you could be a little tight on the valves.

bring the crank to zero, check the rotor. if on 1, go around again, and check that it's at 6, then pull and flip to 1.. try and run it..

good luck !!!
 
Yes, we went off of the rocker at #1. As for the valves, we started on #1, then I torqued down until the rocker was just against and then went 1/4 turn. We then rotated with a large socket and breaker bar and tightened the valves in firing order, going off of where the rockers were to tell us which valve was at TDC. We also had put a paint mark on the crank and timing degrees to show us when we were on TDC. When cranking the motor nothing sounds wrong.

On Sun. we are going to pull the spark plug in #1 cylinder and turn the motor by hand (we may have to pull all the plugs to eliminate compression) to see when we hit the compression stroke and are at TDC on #1 cylinder. Then the distributer should be pointing at #1 and if not we pull the distributer and put it back in pointing at #1. Start the motor and put our timing light on to get the timing exactly on 8 degrees BTDC. Correct? When we are checking, if we notice that #1 is on the exhaust stroke when the distributer is pointing at #1 we'll pull the distributer and turn a complete revolution until #1 is on the compression stroke and the put the distributer in pointing at #1. Any ideas or suggestions please let me know. Thank you all, Bob
 
OK, here is what we did today but still no start up. We checked the distributer and it was off (pointing at #2 instead of #1. We corrected that but it coughed thru the carb yet. #2 and #4 wires were switched at the plugs so we fixed that. Now the motor doesn't cough thru the carb or backfire but no start. We have very strong spark from the coil, and strong spark at the plugs. Sprayed starter fluid down the carb but not even a pop. We know the motor has good compression so we turned the distributer as we cranked the motor but still no attempt to start. Then we noticed exhaust would build up pressure and leak out at the bellows and riser connection. Now, if we have a restriction which fails to allow the exhaust out wouldn't that build up to the point of not allowing the carb to draw air in and down thru the intake manifold. This would have the same effect as no fuel into the cylinders and a no start problem. Perhaps a mouse built a nest inside over the winter. Anyway, I'll let you all know how I do later this week. Please keep any suggestions coming, Thank you, Bob
 
It is a stern drive and no, we did not check the flappers. What do I want to look for? I know they should move freely and not be frooze up but what else? Thank you, Bob
 
that one didn't fall down and block the exhaust. Ok pull the risers pull the plug of the bilge,put water to the drive and start the motor you will have water shooting out the mani but the motor should run if it does do so for only a few seconds.

Then you know it's the riser or after the riser the blockage, not water shooting out it's before the riser the blockage.

Hippie i came back to edit cause i just don't really understand this thread at all.

Who set this motor up and did the rebuild, wires crossed dist set up wrong, what else is fugazied on the motor sounds like a complete cluster f--k.
 
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I have to ask this. Since it appears that youve followed the std procedure to time your engine and still have no luck. Are you sure when you rebuilt the engine that the cam was timed right???? One tooth off is all it needs to not run.

Also I didnt read any comment about using a timing light to check no. is timed correct.

Last thought, are your sure your checking the plug wire in the cap using the correct rotation direction????
 
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Pilot, we checked all that you said and everything is right on except the timing @ idle. We were hoping to get it running then put the timing light on and set at exactly 8 degrees BTDC @ idle (600 RPMs) and see if we are at 32 degrees @ about 2800-3000 RPMs.
Chiefalen, we have everything under control and not really a CF. We just have to iron out the small bumps, thats all.

If anyone has any suggestions please post them. Thank you all again, Bob
 
after all is checked, i hope it runs. if not then readjust the valves. I do the final adjustment running on the water gets a little messy, so have plenty of rags.

May i ask is this motor on a stand ?
 
hippie said:
Pilot, we checked all that you said and everything is right on except the timing @ idle. We were hoping to get it running then put the timing light on and set at exactly 8 degrees BTDC @ idle (600 RPMs) and see if we are at 32 degrees @ about 2800-3000 RPMs.
Chiefalen, we have everything under control and not really a CF. We just have to iron out the small bumps, thats all.

If anyone has any suggestions please post them. Thank you all again, Bob
Click to expand...

If you check timing with the light as your trying to start it, Im thinking you will see your problem. If no 1 is off so are all the rest. If no 1 is set at tdc to start and you have the fireing order correct and wont start. then your problem will lie elsewhere. Did you pull the timing cover to check the timing marks? I know its a hassel but might be time saved. At least to confirm timing marks are correct.
My 45 yrs of automotive experiance in engines tells me this

problem lies with

Spark timing. wrong fireing order

cam timing, missed a tooth. Even with all my time working on engines and rebuilding I still worry about geting the cam timing off. I spend a lot of time being damn sure its dead ass on before I put it back rogether.

wireing the plugs in the reverse rotation.

Which plug location are you useing for no. 1

Im sure you have checked all these but I suggest you go over them all one more time.

Good luck!!! Im sure your problem will something simple. A kick myself in the butt kind of thing!!!!
 
one last thought.
Not knowing your knowledge of engines and hyd valve sytems or the knowledge of the person who rebuilt your engine.

Intial settings of the valves is to rotate the engine by hand, with all valves loose, bring up the two valves on #1 until they stop moving, this is the top of the compression stroke. Loosen the adjusting nuts until the rocker arms are both loose. Tighten the nuts just enough to take away the clearance between the rocker arm and the valve stem. Then turn 3/4 turn tight slowly, not all at once. Got to the next valve on that cyl. and repeat. rotate the engine by hand to the next cyl in the fireing order and repeat. Do each cylinder in the fireing order. Once the engine has run and warmed up readjust all the valves to one turn tight. Back off the rocker arm nut until you hear the valve Click then slowly tighten until the click goes away, proceed to tighten, SLOWLY while the engine is running to 1 full turn tight. This can be a bit messy Take your time. If the valves were set by just cranking them down without following the fireing order you may have done sever damage to your engine........
 
Chiefalen- motor was on a stand but now in the boat.
Pilot481- We rechecked all you suggested about 6 times, all are right on. Also, we adjusted the valves exactly as you described only I think we turned 1/4 turn instead of 3/4.
Tunaman- no, the cam was not removed.

I hope this helps, thanks again men, Bob
 
hippie said:
Chiefalen- motor was on a stand but now in the boat.
Pilot481- We rechecked all you suggested about 6 times, all are right on. Also, we adjusted the valves exactly as you described only I think we turned 1/4 turn instead of 3/4.
Tunaman- no, the cam was not removed.

I hope this helps, thanks again men, Bob
Click to expand...

You really need to set those valves. 1/4 turn wont do it. The intent is to bring the plunger in the lifter to the middle of its travel as it is now 1/4 turn is not going to give you full action on the valves. Probablty not the root cause of your problem but its no good at 1/4 turn past zero lash. are you sure your setting the timing on the compression stroke? No 1 hole, timing mark at tdc on the damper and both valves closed.????
Im sorry we keep coming back to that but your discription sounds classic out of time.
 
Doc- Something is amiss! Looking at 3A-20, if the distributer cap is an exact depiction something is way wrong. My cap has #1 wire where the pic shows #5 wire. Mine starts at #1 and follows the firing order right around the cap. What I see in the pic does not match up with our cap. Ahhhh, please give me some direction here. Should I change the spark plug wires on the dist. cap to match what your diagram shows? If so, then we will have to pull the dist. and replace it back in so the rotor is pointing at the "new" #1. Our cap is numbered with the wires going to a cylinder. Please advise. Thank you very much, I think we found our problem. Bob
 
The absolute position of the #1 wire isn't critical as long as you can adjust the distributor to get the timing correct. The "factory " orientation of the distributor ensures this happens. Your best bet is to "do it by the book" so you don't introduce any new issues.

Regarding the valve lash, 1/4 turn past "zero lash" should allow the engine to run just fine, if it was done correctly. The drawback is you loose some of the "self adjusting" capability of the valve train.

If the exhaust if blocked, you won't get any airflow into the engine. A vacuum gauge should show a good deflection during cranking. Any option (a bit riskier) is to put your hand over the carb throat to see if any vacuum is created.
 
Makomark, Thank you, you answered all questions in your last post. I'll head down and put the wires in their correct positions on the dist. cap and open the starboard side exhaust to look at the flapper. We cleaned the risers and exhaust manifolds when putting it back together. Thanks again to all who helped with suggestions, I hope the wire positions on the dist. cap clear everything up, Bob
 
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makomark said:
The absolute position of the #1 wire isn't critical as long as you can adjust the distributor to get the timing correct. The "factory " orientation of the distributor ensures this happens. Your best bet is to "do it by the book" so you don't introduce any new issues.

If your dist has no vaccum advance diaphgram the above works fine otherwise the intake manifold may interfer with your final timing adjustments. Yes by the book for sure.......

Regarding the valve lash, 1/4 turn past "zero lash" should allow the engine to run just fine, if it was done correctly. The drawback is you loose some of the "self adjusting" capability of the valve train.

1/4 turn is not a correct adjustment as a final setting. Set it up correctly in the beginning and save the time of haveing to go back and re do it.. Check your book for the correct spec, Some chevs want 3/4 turn others want 1 full turn as a final setting.

If the exhaust if blocked, you won't get any airflow into the engine. A vacuum gauge should show a good deflection during cranking. Any option (a bit riskier) is to put your hand over the carb throat to see if any vacuum is created.
Click to expand...

All the above is of course correct and easy enough for an experianced mechanic, but following the book by the letter is going to be much easier for a novice and less expensive.
 
If you disregard where #1 is supposed to be to get the motor running is ok for now.
Find #1 TDC compression, where the rotor points we will call #1 regardless of the number on the cap,from there 1,8,4,3,6,5,7,2 in a clockwise order.The manual depicts the cylinder numbering but here it is
front of motor
1,2
3,4
5,6
7,8
rear of motor
 
OK, here is what we did today. Checked the timing via the rotor and it was dead on. No start though. Two additional mechanics arrived and they thought the timing was off but dead on for them. Still no start. Pulled valve covers and adjusted all valves. (When we put it together last fall we put a drill motor in the dist. and spun the oil to pump up the lifters. I then gave 1/4 turn after the push rods were just touching the rockers. My associate said they were too loose so we gave them 1/2 turn more. (total of 3/4 turn). The mechanic today said they were too tight and therefore we had no compression in two cylinders and turning the motor was pulling down our batteries. Anyway, with the valves adjusted we now had good strong compression in all cylinders. Still no start. Checked the coil and wire at the plugs and they had strong blue spark. No start again. We then pulled all plugs again and only two were barely damp with gasoline! We poured gas down the carb but no start. We sprayed eythanol down the carb but no start. The carb was rebuilt and cleaned last spring and I only put 3 or 4 miles on it all last year. However, in keeping with the saying- spark, compression and fuel equals bang, I torn the carb off and my associate is rebuilding it as we speak. When we lifted the carb off all kinds of gas ran out. Anyway, I'll keep you men posted on what happens. Thank you, Bob
 
PS- I forgot but I pulled the bellows off where the "clapper" is located. The clapper was wide open and so we pput a hos down and the water came out the O.D. with no problem so that is not clogged. Bob
 
Back to the beginning:
It sounds like you adjusted the valves wrong,The rocker positions are E I I E E I I E
start by loosening the rockers, turn motor over untill you see the intake rocker open the valve and close the valve on that cylinder, tighten nuts untill you cannot spin the pushrod with your fingers, then 1/2 turn more.Do this for all the cylinders.

Now , locate #1 intake, turn motor over untill the rocker opens and closes the valve, watch the timing mark to get to "O" on the pointer, this is TDC ,look to see where the rotor is pointing, this lug will be called #1, in a clockwise direction install the plug wires 1,8,4,3,6,5,7,2
Let us know what happens.
When you rebuilt the motor, what new parts were installed,
 
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