Thread: 350 Breaking Up

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Hey guys and gals.

New member here, searched a bit and I've been all over Google and I'm still not sure what the issue is.
I have a small block 350 that I'm told was an 80sish crate and it's installed in something else. Not a conventional hotrod like a lot of you have, but it's in an 88 Supra, and is mated to a TH200R4. I know it has an Edelbrock 1405, but other than that the internals are a bit of a mystery as I purchased the car already assembled.

Today I tinkered a bit with the by-ear method of setting the idle mixture, and it's at about 12 degrees at idle with around 32 degrees of advance all in at 3500, assuming that the camshaft is positioned correctly.

If I get on the gas from a stop it has like no balls at all, and when it reaches around 3500 to 4000 RPM it just chops up, misfires, and just has no power. I "fixed" this issue two weeks ago by replacing the cap and rotor on the distributor, but it seems to be back now.

I'm going to pull the plugs soon and have a look, maybe it's as easy as that, but I doubt it.

Questions are as follows:

One, the fuel pressure regulator on it seems to do absolutely nothing when I adjust it at idle. There's a gauge on there, non-liquid filled, that always reads below 3PSI, even with a really good rip of the throttle. What gives?

Two, is it possible that the plug wire diameter is just too big? These seem like some massive wires to me but I've never dealt with a SBC before so I could be wrong.

Three, I know that the Edelbrock carbs, especially the performers, can be a little wonky out of the gate and I haven't really gotten into it yet to adjust it. Could it be a fuel mixture issue?

I know I'm either running out of spark or fuel at this point, so I'm looking for the easiest stuff to try out. I have no idea what fuel pump is on this thing, or even where it's at, but I plan to replace it.

Side note, it takes a solid kick in the throttle to fire up, and even then I'll sit with the key turned for ten or fifteen seconds before it'll start. I know that might be a timing issue, but I'm thinking it's more likely a carb issue.

Any help, or an idea of where to start would be greatly appreciated.

Thanks!

Plugged up fuel filter or supply lines--------

I got the fuel pressure regulator to work and it shows about 3.5psi so I don't think it's a fuel delivery issue, it stays steady through the revs at about there in park or neutral.

I replaced the plugs and wires, popped off a valve cover and found TDC, and put everything back where it should go and that didn't solve my problem.

Not sure where to look at this point, the distributor seems to be working correctly and I verified spark with a timing light. Timing is set at about 10 degrees initial, and it goes up to nearly 40 at 3k so I'm going to have to weight it correctly.

Do you have a vacuum gauge? If not pick one up, it'll be a big help in diagnosing and also adjusting the carb.

Originally Posted by tunerpunk

I got the fuel pressure regulator to work and it shows about 3.5psi so I don't think it's a fuel delivery issue, it stays steady through the revs at about there in park or neutral.

I replaced the plugs and wires, popped off a valve cover and found TDC, and put everything back where it should go and that didn't solve my problem.

Not sure where to look at this point, the distributor seems to be working correctly and I verified spark with a timing light. Timing is set at about 10 degrees initial, and it goes up to nearly 40 at 3k so I'm going to have to weight it correctly.

so when you rev it up in park it does not miss ? .. could be wires .. my chevy V6 pinto was giving me that kind problem and i changed all the electronics and finally found the problem to be a bad connection on the starter solenoid that fed the ignition ,, check all connections ..

Originally Posted by HOSS429

so when you rev it up in park it does not miss ? .. could be wires .. my chevy V6 pinto was giving me that kind problem and i changed all the electronics and finally found the problem to be a bad connection on the starter solenoid that fed the ignition ,, check all connections ..

I was wrong, it was misfiring with no load as well. I dropped in a new coil and started it up, went for an open header rip down the frontage road near my house and didn't have any breaking up or anything. I think that's what the issue was, but when I got home my starter died so I have a straight bolt high torque mini on the way. I've had some trouble with starter gears not making it far enough out to engage the flywheel correctly, but this one is adjustable so I think it'll work.

Thanks for the input guys, I'll report back with results when the starter shows up!

The starting issue sounds like the choke is not closing.