Ragged restart.

[mudder]

Hot weather has returned and so has a the ragged restart problem. On restart my 93 runs rough and cleans up its act in a couple of miles. Tried new plugs, cap, rotor and plug wires.
The old plugs were very white so I went cooler.
Any ideas?

[windy1]

restart

ive been having a similar problem. if u, turn key on,then turn off u get a squirt of gas. then turn key on,and see if it starts any easier. if your plugs were white,its lean fuel . what about temp sender? fuel filter? timing? im as bewildered as u. let me know,hoe u fix it? mdoyleufo@gmail.com

[milehighbear]

When was last time you pulled your o2 sensor out and cleaned it or replaced it?

[Dragonhealer]

Hot Restart

Hot weather has returned and so has a the ragged restart problem. On restart my 93 runs rough and cleans up its act in a couple of miles. Tried new plugs, cap, rotor and plug wires.
The old plugs were very white so I went cooler.
Any ideas?

If I read your problem rightly, you probably have a leaky injector.
To test, "T" in a 0-100psi fuel pressure gauge on the fuel supply
hose and run the car for 10 seconds. Turn the car off while observing
the gauge reading. It should drop a little below running pressure
immediately, then take a minimum of 15 minutes to bleed to zero.

[windy1]

o2 sensor

ill get one thanks

[mudder]

Thanks for the leaky injector info! I pulled the plugs while it was running rough and none were wet, much too white though so I went to cooler plugs.
A new O2 sensor didn't help but after all these new parts it runs really well after it clears up. Tears chunks of asphalt up when I light em up.
I think the next thing I will try is exchangeing the air flow sensor with one off a 91. I think that sensor has a temperature sensor embedded in it. When I took off the current one, cleaned it in a nice cool garage and slapped it back on a hot car sitting in the sun it ran good until I took it to town and stopped in a hot parking lot.

[Dragonhealer]

On the EFI engines, the spark plug insulator should be almost white
to white.
The O2 sensor (single wire units), are not active on start up or initial
warm up, but are vitally important once "on line", 30 to 60 seconds
after start up.
You are correct that the IAT (inlet air temp) sensor is inside the AFM
(air flow meter). The AFM is the single most important part of the engine
management.

[Advancedynamix]

Sorry to thread Jack a little here, but I have a similar problem with my 93 auto. When it's cold outside the car starts right up, but when it's hot ( after work in the afternoon) the car cranks over for almost 15 seconds and then it idles rough for a few seconds. A leaky injector would cause slow starting no matter what temp right? I'm thinking my afm temp sensor is faulty as well. The car also gets poor fuel mileage ( high 20's) but has a new o2 sensor and good spark plugs.

[FestYboy]

^ need to read the ohms of the ITS and see if it's not pegged (biased). if it is, that may be why it doesn't like to start in hot weather (too much fuel on startup). try this next time you start it in not weather: give it 1/8th throttle before and while cranking and see if the trank time decreases. post results.

[Advancedynamix]

Will do, as soon as I get the new radiator and fan in the car. Thanks Arty.

[Dragonhealer]

Perhaps mudder can clarify, in his OP he describes the problem as a
hot re-start, (restarting 2-15min. after a hot shutdown).
In this case, a leaking injector would relieve the residual fuel pressure
in the fuel rail (incidentally flooding one intake runner), and without
fuel pressure, if it is hot enough, the fuel will boil in the rail. so on
hot restart, we get one cyl. temporarily flooded and the overall fuel
mixture super lean due to fuel vapor in the rail. The now pressurized
fuel no longer boils, but the poor running persists until all the vapor
has passed the injectors or the regulator ( on it's way back to the tank).

Charlie, I think your problem is different. New thread?

[Movin]

He said 2 miles?!! That sounds more like how long coolant takes to clear up.

[mudder]

A reman MAF off the 91 didn't fix the ragged restart.
So far, cap, rotor, wires, O2 sensor, MAF and still the same.
It clears up with in a mile or so and starts right up even when hot.
Time to follow Dragonhealers advice and check for leakdown next. When I pull the plugs during the ragged running phase they all look the same though.
Still driveable, just annoying when attempting a speedy get away.

[mudder]

Problem solved.
Extra spark plug washer stuck in the seat.
If you see a rusty green Festiva going down the road with the driver wearing a bag over his head, that will be me.

[georgeb]

My '92 had a hot start prob. I think it was because of loss of residual fuel pressure due to either a leak at the pump connection or a faulty pump check valve. I fixed it by leaving the fuel pump test connector hooked up. I turn the key on for a few seconds to get unvaporized fuel in the rail before I start it. I got a new pump and removed the jumper but it was slow starting one time so I put it back in to stay.