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Discussion Starter #1
Hey guys, My engine here lately has been acting wierd. I go to start it up and it idols fine but when i put it into gear it starts to chug, sputter and choke. Wierder yet, when i go to accelerate the motor starts to sputter even more and will shake the whole car. It has no acceleration to it what so ever. The mortor chugs so bad it literally shakes the hell out of the car. Im wondering if it could be a problem realated to the carb and intake manifold combination or the camshaft and lifters. What are your guys' thoughts on it.


Thanks- Zeb
 

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I have a couple question for you. Does it ever get past the sluggishness and run proper, or does it always sputter and cough? Second, does it ever backfire through the carberator. One of the first things I'd check is the plug routing 1-8-4-3-6-5-7-2 and make sure none of the plug wires have come loose. It's also worthwhile to pull the distributor cap and make sure the rotor is in good shape and that the center electrode is fine as well.

A little more detail about your car would help. Is this a first gen with breaker point ignition, HEI, computer controlled...?
 

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Discussion Starter #3
Well its a73 small block 350 with HEI in an 87 Camaro. It tends to backfire through the exhaust and chugs and what not even at normal running temp. About 160 degrees.I forgot to mention that there is a awful banging noise resulting from it. I am wonder if the timing could actually be to blame. It Has all new plugs, wires, distrubuter and rotor on it. Is it possible the distributer is on to tight? I just got to thinking if my engine timeing being off could cause it??? Do u think this is a possibility??? Let me know if you think of any other possible causes and what not. Thanks for the reply!!!!
- Zeb
 

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If the timing is too advanced, it will be hard to start (slow cranking) and may even kick back against the starter on occation. If it is too retarded, it will crank and crank with an occational hit and eventually will start. Sounds more like a couple swapped plug wires in your case, or a rotor / cap problem. But I would shoot it with a timing light to see what it is really doing. Is the HEI matched up with the ECM in your 87? There were 1/2 dozen different designs of HEI distributors. The later ones were controlled entirely by the ECM which I think yours should be. With a timing light you should see about 15* advance or more at idle. As you rev the throttle, the timing should drop back slightly and then advance with about 36* total advance around 2500 - 3000 RPMs. BTW, there is a procedure for setting the base timing that requires shorting a couple wires together if memory serves. Perhaps another 3rd-genner can clarify those details. In short, my point is to observe the timing to make sure it's working properly and inspect the firing order and rotor / cap.
 

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You say "all new plugs and wires" so my guess is firing order got messed up. Assuming that it ran OK prior to plugs and wires install, that's about the only thing that would mess up the running.

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Before I pulled the distributor, I'd simply check the routing of the wires. If that looks ok, then I would bring the engine up to TDC, then pull the distributor. Pull the cap, and drop it back in with the rotor pointing to the wire you want to be cylinder #1. You may need to turn your oil pump with a long screwdriver to line things up. Once the distributor is in and the rotor is point to #1, put the cap back on. At this point, the firing order is:1-8-4-6-5-3-7-2- Trace the wires to each cylinder. 1,3,5,7 on drivers, and 2,4,6,8 on passenger. I'm with the other guys, a couple of wires crossed would cause the problems you describe. The car would shake rattle and roll, but barely run. I'm suprised it would idle smoothly. By taking the steps outlined, you will also insure that the distributor is not "out" a tooth, but by all means check the routing of the wires first.
 

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Bob Brissie said:
,,,the firing order is:1-8-4-6-5-3-7-2...
I thought it was 1-8-4-3-6-5-7-2. Better check the intake or service manual to make certain.
 

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1-8-4-3-6-5-7-2

just for kicks, check 5&7- i bet they are crossed. it is really easy to do.
 

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Discussion Starter #9
I've checked the wires and they are all right. Cant get it gunned for timing cause i cant even start it at the moment. Im in the process of installing a cam and lifter kit, carb, and intake hehe!! My guess is the timings to retarded. When its at idle it idles fine, but when you put it into gear you put a different load on the motor which is where it can be faulting. Yeah, when i drive it it shakes the crap out of the car, it knocks, sputters, chokes, and literally runs like $h*t. If im not careful it will sometimes die even under the throttle. Do you guys agree about the timing??? Let me know. Thanks Guys!!- Zeb:beers:

Oh, does anyone happen to know where i could get some ground effects of a RS or an IROCK. For cheap, haha?!?! Later guys-Zeb
 

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One thing you should do is verify that the 0* mark aligns with top dead center. If the engine has been rebuilt, there could have been a harmonic balancer mix up. Also, the harmonic balancer could have slipped on the rubber. The end result being, your marks point to proper base timing but in reality they can be off significantly.

While installing the cam, etc take the time to locate TDC. Here is a poor-mans piston stop technique that works well. Stick a piece of 1/4" soft copper tubing in the #1 cylinder when it is near TDC. When you have crushed the copper tubing put a mark on the balancer at the 0* position. Next pull out the tubing and rotate the engine past TDC. Reinsert the tubing and back the motor up until it stops against the tubing again. Put another mark at the 0* position. 1/2 way between your two marks is TDC and should line up with the scribe on the balancer.

I belive you have a flat-tappet cam there. Break in is very important. If you don't get the motor fired off right away and reved up to 2000 RPM + for 15 minutes or so, you may very well loose a cam lobe. Long story short, be sure to verify the base timing, plug wires, plugs, rotor before firing it off. You don't want to be troubleshooting those basic things on a brand-new cam.

When you fire the motor for the first time, it's good to have a helper. Have someone start the motor while you monkey with the distributor. Just set the distributor clamp tight enough to prevent it from moving around on it's own, but loose enough that you can adjust it by hand. While the cranker cranks, shoot the timing mark with a gun in your left hand while moving the distributor with your right. See my post above about how to listen for correct timing. Don't worry about the timing being exactly right for that initial cam breakin period. Just get it running and tweak it after the 15-20min breakin at 2000 RPM +.
 
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