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Old 08-12-2008, 03:06 PM
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1970 GTO has no power???

Hey guys, thanks again for having me on this site, I just got my 1970 GTO back from bodywork/paint. Its been sitting for around 10 yrs with minimal driving. It was rebuilt around that time I believe, with a mild cam, Eddlebrock mid-rise intake with matching Eddlebrock carb. From what I can gather, the block is out of a 75 Transam. I thought driving it a bit, fresh plugs, and fuel filter would do the trick, but it still runs like its "loaded up"? I put an XRI electric points system also. It also doesn't kick down into passing gear at WOT. I know that I should be able to burn the tires off, but it barely brakes them loose?? Any and all input would be appreciated, I'll attach photos of the kickdown switch, and also the carb/distributor area to see if anyone can pick out a problem. Thanks again!!
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Old 08-12-2008, 04:07 PM
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I would check all the standard stuff first, timing, dwell etc. Also if there is 10 year old gas in it, drain it or at a minimum add some new fresh gas

Chet
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Old 08-12-2008, 04:17 PM
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Quote:
but it still runs like its "loaded up"?


2 different Edelbrocks I have had:

-one had the float set way too high

-one had a float half filled with gas. That would show as hard start after it sits a while after being run at operating temps. Gas would be seen dribbling inside the carb after shutdown also.





Like was said; normal stuff first; timing at idle as well as total advance.



The kick down switch can be tested with a test light or voltmeter with the engine off, and key on. Press the pedal down to see if & when the switch makes a complete circuit.
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Old 08-12-2008, 06:29 PM
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Gto

Go back to original set up on distributor, is vacuum advance working?
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Old 08-12-2008, 11:27 PM
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The gas is new, plus a can of sea-foam, I'm trying to find timing specs, for the motor its a 75 Transam block??? I've got it set around 8 deg right now. It starts with just an easy turn of the key when warm, a few pumps when cold. I can't seem to find where the wire for the kickdown switch connects to the transmission?? As for the dwell, I replaced the points with XRI electronic conversion.....how do you check to see if the vac advance is working?????
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Old 08-13-2008, 09:17 AM
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What transmission are you running?

Apply vacuum to the distributor with a vacuum gun and watch and see if the linkage in the distributor moves. If you don't have a gun, you can give the hose a suck to see if it moves too. I bit of lube-plate on the wear surface would help too.
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Old 08-13-2008, 09:24 AM
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I'm assuming you have a 400 w/elec kickdown.

With the engine off, push gas pedal to floor, check pink wire (switched power wire)to K/D switch for power. Use a test light and make sure is connected to ground. If it lights, go to transmission and do the same procedure.
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Old 08-13-2008, 10:57 AM
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Thanks a million for all the responses/input! as you can tell I haven't had much experience with this GTO/400.

Its got a 400 Turbo Trans.

I checked the switch near the gas pedal it appears to be working fine, but I can't find any wires on the transmission?? Where do I need to look?

I also do not have a vac gun, does the car need to be running to check the vac advance?
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Old 08-13-2008, 11:25 AM
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to check if the vac advance is working just read the timing at 3,000 rpms with it plugged off (ex:36*?) and plugged in at 3,000 (ex:50*=working and calibrated to add upto 14*) ....

fuel pump rubber diaphrams don't do well sitting dry for ten years,,,they dry out and crack....
the edelbrock wants minumum 3.0 to max 5.5psi pump pressure...

my $.02:
just drive it normal for maybe atleast 300 road miles, to give all the fluids a chance to work, to clean and "rejuvenate" all the motor and tranny parts....
then start sorting out the tune up....
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Old 08-13-2008, 01:22 PM
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What else does it have from 1975? Heads? If it was replaced with the 75 engine and then you haven't driven it for 10 years, it might just be that you forget how wimpy the 75 engine is. The hottest poncho engine you could get in 75 was the 255hp 455. 400s were more like 190-215 hp.

I guess trying to compare a 75 engine with a 70 is maybe the first problem.
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Old 08-13-2008, 08:29 PM
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A carb thats running too lean will make an engine fall flat on its face. Edelbrock carbs usually run pretty lean out of the box. You could try a bigger accelerator pump nozzle #1475(nozzles) 1499(gaskets) and a tuning kit, try a smaller rod and a stiffer spring in the primary's. Extremely easy to change. It cured my car after thinking it was a distributor/timing issue for a year.
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Old 08-13-2008, 08:49 PM
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Wow you guys are good! Thanks for all the responses!! I had good friend -mechanic take a listen, and he says its definelty distributor/electrical. He wasn't able to tear into yet. I'm also wondering what I should be setting the timing at, its at around 9 deg right now, but with a crane cam (no other info) should I be advancing it more??? I spoke with the previous owner, and he says with some different tires, he could launch the front end off the ground????(whatever) I should be able to at least leave a patch of rubber..
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Old 08-14-2008, 09:22 AM
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suggestion:
DO use a pcv valve (I noticed your's is plugged off in the pic')...
there is alot of nasty (acid) stuff in the block that you do want to get rid of as quickly as possible for longer bearings and rings and valves life

second reason to use one is the carb enrichment curves were engineered including the air cfm thru the pcv carb port to determine the A/F mix at high Hg.....
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Old 08-14-2008, 03:48 PM
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IT WORKS!! with all your input I now have a real mean GTO!! I found that the kickdown wire to the transmission was no existant, and rewired it. I now get the passing gear, and my L1 works too!!! I also plugged my vacuum advance port on the carb, apparently the weights on the dristributor weren't doing the job. I can now get the tires to break loose at all shift points, even at around 50 mph!!! HOLY BALLS!! Thanks again for the input, without it I would be driving a dog!!
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