1977 Engine Problems 429
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1977 Engine Problems 429
Hey guys, getting frustrated with my dent, i bought it about 2 months ago and have been fixing things up as i can.
The truck will fire up and run fine when it's cold, but once it's warm it labors to turn back over and typically will not re-start.
Here's what i know/have done.
The engine is a big block 429 from i believe a 1970 thunderbird
Edelbrock intake
edelbrock carb
mid length headers
I've put new plugs in
all new battery cables on
new alternator
new starter (old one did the same thing)
It makes me think vapor lock so I:
added a fuel pressure gauge to verify (5psi) from the mechanical pump
added a clear fuel filter to make sure fuel is moving/staying in the line.
The truck does not seem to want to run down the road well at all unless it has around 30* of timing in it, does this seem normal?
I'm just not sure what else to try... i've read that also the coil can get hot and not want to function? I ran it last night to where it wouldn't start and the coil wasn't hot to the touch.
I don't see how the coil being an issue could make the truck hard to turn over. Could this be a wiring/ground issue? I did notice that there is NOT a large ground from the block to the frame anywhere.
The truck will fire up and run fine when it's cold, but once it's warm it labors to turn back over and typically will not re-start.
Here's what i know/have done.
The engine is a big block 429 from i believe a 1970 thunderbird
Edelbrock intake
edelbrock carb
mid length headers
I've put new plugs in
all new battery cables on
new alternator
new starter (old one did the same thing)
It makes me think vapor lock so I:
added a fuel pressure gauge to verify (5psi) from the mechanical pump
added a clear fuel filter to make sure fuel is moving/staying in the line.
The truck does not seem to want to run down the road well at all unless it has around 30* of timing in it, does this seem normal?
I'm just not sure what else to try... i've read that also the coil can get hot and not want to function? I ran it last night to where it wouldn't start and the coil wasn't hot to the touch.
I don't see how the coil being an issue could make the truck hard to turn over. Could this be a wiring/ground issue? I did notice that there is NOT a large ground from the block to the frame anywhere.
Tuned
Joined: Nov 2010
Posts: 426
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From: Caledon ON
Hard to turn over when hot typically means the timing is too far advanced. 30 degrees initial advance is way to much, something is wrong. Should be anywhere from 6 to 12 degrees for most fords, I'm not sure what the spec is for a 429.
Tuned
Joined: Nov 2010
Posts: 426
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From: Caledon ON
Is there anything done to the engine like a cam or anything. Have you set the timing with the vacuum advance disconnected? It must be disconected and the vacuum line plugged. Have you verified TDC at #1 cylinder and then looked at the timing marks on the balancer to ensure the balancer marks are accurate? I have seen balancer outer rings slip on the rubber causing inaccurate timing marks.
If the engine is stock and you had the vacuum advance disconnected then I would suspect a vacuum leak somewhere.
If the engine is stock and you had the vacuum advance disconnected then I would suspect a vacuum leak somewhere.
Tuned
Joined: Nov 2010
Posts: 426
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From: Caledon ON
I just reread you post. I see the intake and carb have been changed. I would suspect a vacuum leak for sure. You can check by using a mechanics stethoscope around the edges of the intake sealing surface and the carb base and any of the vacuum lines and plugs.
Mechanic's Stethoscope
Mechanic's Stethoscope
Tuned
Joined: Nov 2010
Posts: 426
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From: Caledon ON
Yes, a vacuum leak will cause the engine to run rough at idle and not be responsive. Advanced timing will mask this condition. I'll ask again though, is there an aftermarket cam in it?
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Tuned
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Bringing this one back up as i had a chance to troubleshoot a bit more yesterday. I did find a small open vacuum port on a fitting coming off the intake.
So i plugged that port and got the timing set back to 8*. The truck idled smoothly for a few minutes, i went to go for a test drive (coolant temp was showing 190*) as soon as i got to the end of the driveway it stalled out and would not re-start as it was doing before.
When the truck is warm like this it's like the starter has a REALLY hard time even turning the truck over, and sometimes wont.
Starter is brand new and works perfectly when cool.
Any more ideas?
So i plugged that port and got the timing set back to 8*. The truck idled smoothly for a few minutes, i went to go for a test drive (coolant temp was showing 190*) as soon as i got to the end of the driveway it stalled out and would not re-start as it was doing before.
When the truck is warm like this it's like the starter has a REALLY hard time even turning the truck over, and sometimes wont.
Starter is brand new and works perfectly when cool.
Any more ideas?
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
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From: Simi Valley, CA
No 1972 or earlier FoMoCo vehicle has an EGR valve, as they were introduced in 1973.
still between the carb and intake?
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