Rough Ruby

So as you all know, Ruby has sat for 2.5 years with occaisional (twice a month) starts and laps around the block.
She's been back on the road for about 150 miles. On cold starts, she runs pretty rough and you have to turn off the AC or she'll stall.
Within about 2-3 minutes though, it clears up and idles and runs out fine.

Any ideas?

voted

Tom C.

Voted as well

Voted.

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This alone is the reason I ONLY run marine (non-ethanol) gasoline in anything that sits for longer than 30 days.

First thing I'd do is datalog and make sure none of the sensors are giving wacky data. Second is I'd run a few more tankfuls of fuel through with some fuel injector cleaner and see if that does anything.

After that, I'd look at swapping injectors from a good car and see if the idle cleans up. If it does, then you know the injectors didn't survive the storage.

Italian tune up time.

drive more..........................

COL

Clean the IAC. Fill the tank with some good gas and a couple bottles of Techron.

Where's the option for "give it a well deserved tune up"?

I can't decide if the Seafoam option or swapping out parts could be interpreted as such.

I would give it a fresh tank of gas or two first tho.

Talk about a decisive person. Yep.

Open Loop occurs for about the first 2-3 minutes, usually 180 secs, OR until a certain engine temp is reached. To my limited knowledge, this is also one of the times the A.I.R. circuit is active. Does it stop when you reach a certain Temp? Is it consistent? Time it. Is it always the same time or temp reached?

I don't know if "Ruby" is TBI or LTI, so I'm not even sure if you HAVE an Air circuit on your engine. I'm on TPI. MY AIR circuit was removed and programmed out of the ECM years ago. There is likely to be an electrical connection that actuates the AIR system. Unplug it. Start it. (you might get a a check engine light) Any difference. There should be.

If it makes no difference, it's possible that your AIR valve or solenoid is not working. Therefore the extra o2 that SHOULD be there, isn't, and is being incorrectly accounted for at idle/low load. Forgive me if I'm off base. I don't mean to waste your time or energies, as it has been several years since I had to worry about, or even think about that circuit.

Here's a link to an article about the AIR circuit. From the discussion, you can appreciate how if the circuit is active but not functioning, that it will mess up your warm up periods.

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Dave

jayoldschool wrote:

Italian tune up time.

explain in full details........

Ruby is a TBI 305.

Italian tune up.

It gets stolen and dumped into a canal or river. Dead body in trunk.

(Crap..wagons don't have trunks! Make the dead body optional along with the class 3 hitch)

I'm sure that the average italian's body will fit in the rear footwell under the cargo floor.....

Sorry, didn't think that everyone doesn't know what all of my cars are engine wise. Roo is correct.
92 - L03.

Yes, my first thought was new plugs, wires, etc. but after about 3 minutes it clears right up. When we first put plates on it, it ran REALLY crappy and I barely made it half a mile to gas station.
I bought premium in it as I know they have cleaners, etc. and drove to the auto parts store.

With fresh gas, it got mariginally better. Once the seafoam went it, it got better still.
I figure another tank or two and maybe another can of seafoam and it should be okay.

I was thinking the choke wasn't working or something..

I agree with Dave in regards to this being an open loop/closed loop thing. Correct me if i'm wrong, but it was always my impression that the O2s don't kick in untill they are up to temps and a certain engine temp is acheived. Was unaware that the O2s were even referenced before the system went into closed loop.

I would look first at the idle air motor. If it is not seating than the engine is getting too much air that can't be compensated by the O2s signalling more fuel.

The computer engine temp sensor. If it is wrong than the default may be to real cold and thus too much fuel.

EGR valve. Again if it's not seating, than there is no O2 to tell the ECM to compensate for the added exhaust to the mix.

Either that or Ruby is just grumpy in the morning and objects to not being run very often. My wife is like that. Occasionally I have to bang her head on the wall to get her heart started.


Bill

O2 sensor is not used during initial start-up, the single wire O2 sensors depends on exhaust heat to reach operating temperature to become effective (closed loop). The single wire O2 sensors typically go into open loop at idle anyhow.

An EGR sticking slightly open will constantly cause a rough idle, even in closed loop. MAP sensor values will be affected and therefore continuously effect idle due to lower engine vacuum being reported, read that as an engine load.

The ECT sensor could cause some running issues if skewed and will typically skew over the entire range.

A.I.R. system typically only works for less than a minute on a cold start to help light-off the catalytic converter quicker. Secondary air is injected into the exhaust pre-cat and with the O2 sensors in open loop, it will not effect engine operation at idle. Also, TBI engines did not typically have this system, unless it had California emissions.

The IAC valve, if faulty, could cause either a fixed, high or low idle. Most are 4-wire actuators and contain 2 stepper motors to control the pintle position. Can be seen on a scan tool by looking at the IAC counts.

But what comes to mind with an initial start-up rough idle is carbon build-up on the intake valves. Think of it like this, the carbon on the valves act like a dry sponge and it's not until the sponge becomes saturated with fuel will the idle straighten out, because now the cylinder will receive the full shot of fuel. Why does it only do it in the morning? After an overnight hot soak the fuel will evaporate from the carbon on the valves and dry out the sponge again. The cycle just repeats itself.

Also take a peek at the distributor magnet and make sure that it is not cracked in several spots. I made a post on this a while ago but, I will say this, it typically is effected more by heat.

convert2diesel wrote:

Either that or Ruby is just grumpy in the morning and objects to not being run very often. My wife is like that. Occasionally I have to bang her head on the wall to get her heart started.
Bill

What size hammer do you suggest for the banging upside the head? What's your technique?
Dave