Several issues after 700R4 swap - any ideas?

[delosh]

Looking for solutions...

67 with stock 283, stock points ignition, stock 2 barrel carb and 3OTT manual.

I just swapped in a fresh 700R4, horrible quality steering column (which I will replace), a Holley 4160 4 barrel carb and Weiand 8150 intake manifold. Along with a long list of supporting parts (starter, flexplate, valve covers with vents, etc.). The carb and intake had to be replaced all because of no TV cable bracket support for the stock setup.

Picked it up yesterday after they were having a weeks worth of problems with the new starter working intermittently - click but not crank. We replaced with another brand new one and it too had the same issue. It started when I left the shop but would not restart after a fill up at the gas station. Waited 15 mins then it finally started.

The shop thought at first my ignition switch was bad because they saw an intermittent voltage drop on key turn (sometimes 12v sometimes 7 volts), but it wasn't, then they thought the 10 year old battery could be to blame – so I replaced it last night and it still presenting the same issue. Any ideas?

Another issue is the engine "missed" several times on the way home during acceleration – even shutting off completely once. Shop thinks perhaps the points setup should be upgraded to a HEI setup due to the carb/intake combo. Thoughts?

[RichardJ]

Don't confuse the ignition circuit with the starter circuit. You've made a number of changes at one time already, so don't introduce a new variable until you have found the existing problem.
With all they changed, I'd first check to see if they removed the engine electrical grounds. The engine must be grounded to the frame and from the frame back to the battery Neg post
Check electrical connection at the junction block on the fender. Check connections for damage and corrosion on the wires going into the bulkhead connector and back out.

[delosh]

Yes, I am thinking of these two issues as unrelated. One is starting issue, one is ignition issue causing engine "missing" with a quick pffft sound.

[Rickysnickers]

I'd start looking at the ground straps as well. I have four ground straps on the truck. Battery to frame, engine to frame, cab to frame and bed to frame.

As far as your carb and the 700r4, have you seen this? I had one from this company and their stuff works really well.

https://www.bowtieoverdrives.com/cat...php?ITEMID=217

[delosh]

For ground straps, there is:

• 4 gauge from battery - to block (water pump bolt)
• 4 gauge from battery - to inner fender, same bolt as OEM braided strap to frame
• 1 gauge from starter - to frame
• OEM braided strap from firewall to valve cover bolt

[delosh]

Originally Posted by Rickysnickers

As far as your carb and the 700r4, have you seen this? I had one from this company and their stuff works really well.

https://www.bowtieoverdrives.com/cat...php?ITEMID=217

I bought a bracket kit for this carb and 700R4... does this one do anything different?

[geezer#99]

Your ‘missed’ is a result of a sudden throttle opening and the motor is too lean (possibly from a cold intake or a vacuum leak) and retarded timing.
As for your bracket kit you didn’t need to change your carb. I’ve seen several 2bbl or 1bbl carbs set up with a custom bracket.

[delosh]

Originally Posted by geezer#99

As for your bracket kit you didn’t need to change your carb. I’ve seen several 2bbl or 1bbl carbs set up with a custom bracket.

I did find an article or two about diy custom brackets for the Rochester carb, but I didn’t want to go that route.

[geezer#99]

Do you have a pic of the top of your motor?

[Jason Banks]

For your starting problem, I would hook up a remote starting switch, like this - https://www.amazon.com/INNOVA-3630-R...dp/B000EVU8MK/

See if it cranks fine that way. If it does, I would troubleshoot the purple wire going to the starter, that provides the crank trigger. Check connection at the starter, then disconnect the harness from the firewall and make sure that connection is not corroded. After that, it's all inside the cab. But you want to check the connection behind the fuse block and then down at the ignition switch(sounds like they already did though).

If it won't crank reliably with the starter switch it is most likely grounding or the power cable, or maybe starter alignment, or flywheel that is incompatible with the starter gear?

[Jason Banks]

Here's an excellent video about how to figure out where you are getting the voltage drop - https://www.youtube.com/watch?v=ry68G0C2Fyc

[delosh]

Originally Posted by geezer#99

Do you have a pic of the top of your motor?

[geezer#99]

Do you have a pcv valve?

What’s your initial timing set at?

[delosh]

Originally Posted by geezer#99

Do you have a pcv valve?

What’s your initial timing set at?

Yes, the silver puck on passenger side valve cover is a pcv. Not sure on the timing.

[geezer#99]

So no working pcv then.
A pcv hooks up to manifold vacuum, not the air cleaner.

Is your vacuum hose for the brake booster hooked to the carb or to a fitting on the intake?
You need to find out what your timing is and/or get a timing light and learn how to use it.

That’s quite the heavy duty carb return spring you’ve got!

[delosh]

Originally Posted by geezer#99

So no working pcv then.
A pcv hooks up to manifold vacuum, not the air cleaner.

Is your vacuum hose for the brake booster hooked to the carb or to a fitting on the intake?
You need to find out what your timing is and/or get a timing light and learn how to use it.

That’s quite the heavy duty carb return spring you’ve got!

Brake booster tube goes to intake fitting. The pcv tube is how Holley told me to route. This used to have the draft tube and vented oil fill cap.

[geezer#99]

The pcv won’t effect your poor running issues as much as a possible vacuum leak and retarded timing will.
Are all of the vacuum ports capped on the carb? I see your vac advance is hooked to ported
source on the carb. I can’t see any others.

[geezer#99]

The pcv won’t effect your poor running issues as much as a possible vacuum leak and retarded timing will.
Are all of the vacuum ports capped on the carb? I see your vac advance is hooked to ported
source on the carb. I can’t see any others.

[RichardJ]

I agree with geezer about the PCV. It doesn't appear to be connected correctly.

>>4 gauge from battery - to block (water pump bolt)
4 gauge from battery - to inner fender, same bolt as OEM braided strap to frame
1 gauge from starter - to frame
OEM braided strap from firewall to valve cover bolt<<

That's a lot of 4 gauge wires connected to the battery or is there a junction block for the Neg battery post. I guess I'd actually have to see where those ground wires actually go and what part the inner fender plays in that. Ha.

If you would, try this. With the engine running, place one lead of your voltmeter, directly to the battery negative post. Place the other voltmeter lead, on any clean, unpainted spot on the engine. Voltmeter should read 0.0 Volts.


The Bat cable on the alternator is much bigger than the original. How are you feeding the bulkhead connector that supplies power to the ignition switch and fuse box. Originally a 12 gauge wire from the battery junction block, is in the harness laying across the radiator support. Wrapped inside the harness, on the driver side is a soldered/crimped junction. A 2nd 12 gauge wire connected that junction to the alternator. A 3rd 12 gauge wire from that junction went over to the bulkhead connector and on into the ignition switch.

[lolcopter]

The starting issue may be from a clearance issue between starter and flywheel. That would explain why it won't start when hot. Try adding a couple of small shims to starter and see if the extra clearance solves issue.

[Rickysnickers]

Originally Posted by delosh

For ground straps, there is:

• 4 gauge from battery - to block (water pump bolt)
• 4 gauge from battery - to inner fender, same bolt as OEM braided strap to frame
• 1 gauge from starter - to frame
• OEM braided strap from firewall to valve cover bolt

Here's a couple of suggestions. I have my truck grounded with this and the grounds have no paint or anything hindering their grounding abilities;
1. Battery to frame
2, The starter is also grounded to the frame.
3. A ground strap off of each cylinder head.
4. Cab to frame
5. Bed to frame.

I use inch wide braided grounding straps. While the grounds may not be your issue, I suspect that one ground you have coming off the valve cover really isn't doing much. The valve cover has a gasket under it and it appears the valve cover is also painted.

[Rickysnickers]

Originally Posted by delosh

I bought a bracket kit for this carb and 700R4... does this one do anything different?

No, it probably does not. I didn't realize what you had hooked up to the current carb.

[delosh]

Originally Posted by RichardJ

That's a lot of 4 gauge wires connected to the battery or is there a junction block for the Neg battery post. I guess I'd actually have to see where those ground wires actually go and what part the inner fender plays in that. Ha.

I have audio style blocks on the battery terminals that allow for two 4/1ga cables and two 8ga wires.

Originally Posted by RichardJ

If you would, try this. With the engine running, place one lead of your voltmeter, directly to the battery negative post. Place the other voltmeter lead, on any clean, unpainted spot on the engine. Voltmeter should read 0.0 Volts.

It read 0.0 volts.

Originally Posted by RichardJ

The Bat cable on the alternator is much bigger than the original. How are you feeding the bulkhead connector that supplies power to the ignition switch and fuse box. Originally a 12 gauge wire from the battery junction block, is in the harness laying across the radiator support. Wrapped inside the harness, on the driver side is a soldered/crimped junction. A 2nd 12 gauge wire connected that junction to the alternator. A 3rd 12 gauge wire from that junction went over to the bulkhead connector and on into the ignition switch.

I swapped to a larger alternator 2 years ago and upgraded the charging cable to 4ga. I removed the old battery junction block on passenger fender and simply re-connected the oem wire back to the battery positive. All other oem wiring was left intact. Has worked perfect since.

[delosh]

Originally Posted by lolcopter

The starting issue may be from a clearance issue between starter and flywheel. That would explain why it won't start when hot. Try adding a couple of small shims to starter and see if the extra clearance solves issue.

It's not only when hot though.

[lolcopter]

Originally Posted by delosh

It's not only when hot though.

Is the no start a slow turn over but won't fire or a click and nothing happens?