1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Yet another no-start thread: Jump starts, but dies below 1500rpm

Old Mar 15, 2005 | 01:29 AM
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Yet another no-start thread: Jump starts, but dies below 1500rpm

I have a 79 with 90K original miles I'm working on, and I'm having some issues.

First, I am definately getting spark to all plugs.

Next, I'm definately getting fuel, as I can see it being squirted into the carb.

Then, it does have compression, 3 nice solid puffs on each rotor.

Finally, it will pull start, BUT it makes a sound that sounds like there's a freaking rock in the engine or something. It's a very loud ticking or banging sound that goes away after you rev it up and the RPMS are dropping (it only goes away as the RPMS drop). The engine will run if we keep it above 1500-3000 RPM, but as soon as it drops below that, no amount of gas will bring it back up.


Any ideas?
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Old Mar 15, 2005 | 01:40 AM
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Probably not it, but. . . . you don't have a vacuum leak, do you?

Probably not it, due to the weird noise. . . . but there's been stranger things happen.
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Old Mar 15, 2005 | 05:41 AM
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Sounds like rocks in the engine? Your timing or fuel is off. I'm betting on the timing seeing as how you have to pull start the engine.
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Old Mar 15, 2005 | 11:01 AM
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Originally Posted by Rotor13B
Sounds like rocks in the engine? Your timing or fuel is off. I'm betting on the timing seeing as how you have to pull start the engine.
Yah, I was wondering about that. We pulled the distributer and it was in backwards, so we fixed that, but it didn't correct the problem. I guess the timing could still be way off or something:S


As for a vacuum leak, we looked pretty hard and couldn't find anything.
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Old Mar 15, 2005 | 11:18 AM
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Have you checked your starter. Becuase my 85 did that same thing happened to mine. so you might just want to check it out.Couldn't hurt right. good luck
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Old Mar 15, 2005 | 02:06 PM
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Originally Posted by Rotor13B
Sounds like rocks in the engine? Your timing or fuel is off. I'm betting on the timing seeing as how you have to pull start the engine.
Timing. Too advanced. Get a timing light and check it.
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Old Mar 16, 2005 | 08:31 PM
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Originally Posted by rx7_1
Have you checked your starter. Becuase my 85 did that same thing happened to mine. so you might just want to check it out.Couldn't hurt right. good luck

Yours did the same thing as far as the sound goes, or the starting problem? The starter is new, but we did have to return the first one we bought because it was FUBAR.
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Old Mar 17, 2005 | 11:24 AM
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how many cold cranking amps is ur battery?
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Old Mar 17, 2005 | 11:50 AM
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Sounds like timing. Look for the timing mark on the pulley make sure it's clean and paint white and yellow marks as appropriate (see manual). Use a timing light to set timing. It won't start with starter because starter won't spin it at the 1800rpm required to run (if you continue to have starter problems put in new battery cables since the old ones are probably corroded aluminum).

I think the 79 has points and condenser, which is poor, but you can static-time that system. You can also convert to electronic with $20 of parts from the junkyard. Note that plug gap is about .30 for mechanical and .60 for electronic so plugs must change.

If electronic ignition make sure ignitors are OK: there are instructions in manual and in our archive for doing this.

B
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