esoteric

It is an '84 El Camino with automatic overdrive trans and only 67k on car, so it has a history of sitting. The car shifts into overdrive at about 35 mph, a speed at which I do most of my driving. While cruising at 35, with my foot barely depressing the gas pedal, I get a slight surge similar to an engine miss. Is there anything I should check or do?

Thanks in advance

PS What heads should I bolt on this box stock thing to improve performance a little? It has a 305 4bbl.

firehawk618

iTrader: (14)

I'm no tranny expert but it kinda sounds like your lockup converter disengaging / engaging.

esoteric

That's what I am thinking, but what can I do about it?

Low N Slow

iTrader: (4)

I had an 86 Caprice with the same drivetrain, the converter would lock and unlock constantly at around 35MPH. I bought a computer chip that cured it and gave it quite a bit more power. I had to run premium gas with the chip but the power gain was worth it.

Rokko

iTrader: (2)

Can you select 3rd gear and leave it there, instead of OD?

Ackattack1

iTrader: (7)

there is a switch in the brake pedal assembly that is used to unlock the torque converter while braking. So it sounds like you are pressing the brake just enough to activate this switch. You can adjust the switch a little. BTW, this same switch is also used to control the brake lights (it's 2 switches in one).

I had to install this same switch in my 72 GMC when I installed the 700R4.

esoteric

Where did you get the chip?

esoteric

I am pushing on the brake, but thanks for the info on the switch.

esoteric

No. I have just 1,2,3 the overdrive is beyond my control, like my wife.

My1st Truck

iTrader: (8)

Now that is funny.

I think edelbrock makes a bunch of crap for that motor, I know a guy I work with has good luck with it.
I will ask him when I see him.

firehawk618

iTrader: (14)

There should be od,3,2,1 on any GM tranny in the 80's and mabey even through the 90's. I believe the only 2 od tranny's they offered were the 200r4 and the 700r4 and both have 4 forward gear positions.

Are you sure it isn't a 3 speed with lockup? Sometimes that will feel like od but it's not.

esoteric

Then it must be a 3 spd. It has only the 3 forward positions on the shifter: R N D 2 1. What is the likely alpha numeric designation for such a trans? I will pay attention to the shifts and try to find a place to go more than 35 mph: I 5 won't work...

WAHUSKER

iTrader: (4)

That's what you get for buying a Chevy....ahem....sorry, no help here John.

My1st Truck

iTrader: (8)

So maybe a turbo 350 in there? Sounds like it could be three speed.
Being that old.

esoteric

I have a lot to learn, again. Already I can see that the SBC has evolved in the last 20 years, some parts interchange, some don't.

Ackattack1

iTrader: (7)

yeah, they made a Turbo 350 that had a lock up converter, I think it's known as the TH350C

esoteric

Is there a code somewhere that would help me identify the thing?

firehawk618

iTrader: (14)

Stock 84 ElCamino's only came with a th-200 with and without od or a th250. As far as telling them apart I have no idea.

esoteric

Thanks for the info. How strong are those units?

NWDragRacer

Well, Turbo GNs used beefed up versions of the TH200. I've seen several behind 500+ inch big blocks.