Stalling/choke light flicker

[Monzadude]

I'm running a stock 2 barrel Rotchester on my 3.8. It was working ok but is now starting to act up. When ideling in gear ( its a th350) the oil/choke light come on . Sometimes it flickers with the engine idle, sometimes it's on solid. If I sit at a red light in gear and then try to give it any gas at all when it turn green the car either stalls or sputters and bogs. Once I get moving it seems fine. If I put it in neutral while waiting then drop it into gear on the green it's fine.

If I sit in park and give it a quick shot of gas it bogs for a second before it revs up.

Just tonight it started stalling when I stop. When I'm slowing to a stop the exhust starts to gurgle and pop, then the oil/choke light comes on. If I don't put it in neutral or give it a shot of gas it stalls once I stop. Then once I start it I have to give it a few good revs before I put it back in gear or it will stall again.

I checked the vacuum lines and the filter and it all looks fine.

I have a good 4 barrel I can put on but I can't find any one around here to tune it for me. The last time I tried on my own all I did was flood the engine really bad.

Most of the problem is lack of knowledge and money on my part. I've been having one problem after another it seems.( Not always this car.) Unfortunately if I don't figure it out soon I'll have to park it for a while until I can afford to have someone fix it for me.
Any ideas?

Bill

[spyder_xlch]

Maybe the light is coming on because of low oil pressure? It might stall, sputter or bog because the fuel pump is cutting out? If you think the choke is to blame, once you get up to normal operating temp wire the chock open and see if that helps.

[Monzadude]

I checked and the choke stays off so that's not it. I turned up the Idle and that helped a little. I went over the whole thing and can't find a vacuum leak or anything obvious. I tried tuning it a little and it seems a little better then it was. ( it'd probably be better it I knew what I was doing)

I've noticed since I played with the adjustments it's also not as hard on gas as it was.

I sat and listened to it idle for a few minutes while I was trying to think of what to do next and noticed it sounds like it's missing a little. The more I listened the more i could tell somethings not firing properly.

I'm going to try changing the cap and rotor and put new wires on it and see how that goes. The plugs are new but I'm going to check them just in case.

Bill

[Sirshredalot]

Its does sound like an oil pressure issue. I believe there is an oil pressure shutout switch where if oil pressure drops below a certain value than it cuts off the fuel pump....that could be why reving it helps.

Do you have an oil pressure gauge on it? what weight oil are you running?

God bless
-Shred

[Monzadude]

I don't have an oil pressure guage yet. I'm planning on getting one soon. I trying to get some extra guages hooked up to see what the engine is doing.
I'm running 10w 30 non synthetic.

I was playing with my dads old timing light last night and found something interesting. I don't know much about them but was following the book that came with it to see what I'd get. It said to disconnect the #1 spark plug wire and replace it with the wire from the timing light. Which I did. Once I started the car the light flashed so weak it wasn't doing any good. I got frustrated and pulled the timing light wire off with the motor running.

Oddly enough it made no difference! the motor ran the same with no wire on one spark plug. It still sounded like there was a small miss but nothing to bad. The motor didn't even run rough. How is that possible?

I shut it down, put the wire back on and started it up again. Everything still ran the same. It doesn't make any sense to me at all.

Maybe once I change the cap, rotor and wires it'll run better.

Also once the guages are in and I know how hot it's running and what the oil pressure is I'll have a better idea of whats happening.


Bill

[spyder_xlch]

Change the plugs while you are at it.

[Sirshredalot]

Sounds like you where getting weak or no spark...

To use a timin light you clip the "clipy thing" around the number one plug wire and attach the other leads to a positive and negative source(battery).
Poit your light at the timing tab and see where and when it flashes.

God bless
-Shred

[spyder_xlch]

I don't think his light had the "clipy thing". Sounds like it is an inline type.

[Monzadude]

Yes the timing light would be the inline type. It replaces the spark plug wire.

The plugs are new. I replaced them when I put the motor back in. I didn't change the cap and everything at the time because that money got used on the mother in laws car.

I got the cap and rotor today but the wires won't be in until tomorrow. As soon as I get them I'll put them on and see if that make a difference.

Bill

[spyder_xlch]

With a weak spark those plugs might need a good cleaning then. But I've also seen new plugs go bad once they get wet and foul. (champions on my dirt bike, first time they fouled they were junk)

[Monzadude]

So I checked the plugs and they were still good. i put the new cap,rotor and wires on. It seems to be running better and smoother but still not quite right.

There's no more miss but still bogs out when it's been idleing in gear for a min or two. It'll idle in park with no problems but in gear the light still flickers and it bogs out when I hit the gas.

While driving slow if I hit the gas too hard it sputters like there's a dead spot in the gas pedal. If the RPMs are up or in neutral it's fine.

To sum it up: If I stop at a light and leave it in drive while I wait it will bog and try to stall once I try to accelerate.

If I drop it into neutal while I wait and put it back in drive before I go it seems fine.

If I turn up the idle it works better but then it revs too high in park or neutral and trys to pull a little in drive at a stop.

Bill

[cammerjeff]

Almost sounds like your Torque Converter is locked up, the stock one in my 78 sunbird wagon acted the same way, and it idled in gear like an odd fire 3.8, shook alot, stumbled off the line unless the idle was set to 1200 rpm, at speed it was fine exept for downshifts. I chased it the entire 1st summer I had the car, someone suggested it, and gave me a known good used converter. I couldn't believe the difference when I put it in!!!!

[Sirshredalot]

Is it the stock transmission? They did have some lock up converters as options but I didnt think it was until 1980.
A locked up torque converter sounds like a good theory...but Ive never seen a non-lockup converter "lock up".

Could also be a lean spot causing the bog or a vacuum leak....Fuel pressure? I think we already went over that in another thread though...it would however not be as apparent in neutral or park because there is no load. Maybe get some vacuum readings or start poking around with a can of carb cleaner.
Also...when you mash the gas it doesnt downshift? Do you have a detent cable hooked up?

Sorry if any of this has already been addressed but its somthing I thought about.

God bless
-Shred

[cammerjeff]

Shred,

It is just something else to consider, I was told by a local trans shop, that about 1 or 2% of the torque converters that fail, "lock up" usually in cars that sit for a leanth of time. My 78 sunbird with the T-350 in it say for over 2 years before I bought it.

[Monzadude]

I was talking about the car last night at work and told one of the guys what it had been doing. He said I should take it to this little garage on the out side of town, that the guy there used to build alot of hot rods and knows the old cars better then the new ones.

I live in a different town from where I work so it was a 25 min drive, which is perfect for the car to be nice and hot to show him what it's doing.

The guy was great. I told him what's been happening and all the ideas you guys have given me.

He listened to the car idle in park and the had me put it in drive. Sure enough, after a min of idling it started to chug then stalled. I restarted it and he had me do it again. This time he had me sit like i was at a light the after about 30 second I hit the gas to move and it sputtered and almost stalled.

He just smiled and started to check a few things. After a few minutes he said he thought maybe I was loosing oil pressure like I was told on here.

He said the vacuum is good, the spark seems good, the torque converter is fine and the carb seems to be working ok.

He said he'd start with the oil pressure switch first. He says I could put in a jumper wire to by pass the switch and make the fuel pump run regardless of the oil pressure( he did tell me it's probably not safe to leave it that way ) and see if that make a difference.

Does anyone know which wires are for the fuel pump? This would be a quick way to find out if thats the problem but I don't want to accidentally fry the fuel pump.

Bill