jeep slow to start when cold

Boom1699 · Jul 11, 2013

i have a 93 with the 4.o and its slow to start when cold but always starts and runs a lil rough if you let out the clutch itl die if you quickly step on the gas it will try to die after it warms up its fine ive cleaned out the iac tps and the throttle body the exhaust is brand new from the header back any ideas anybody

joe_peters · Jul 11, 2013

Define "slow to start"--LONG CRANK TIMES or it TURNS OVER SLOWLY when cranking?

Any mods to the engine?

What about the injectors?

State of tuneup--plugs, wires, rotor, cap?

8Mud · Jul 11, 2013

I'm with Joe, first thing I'd look at is weak spark. Hot motors ignite easier than cold ones do.

Weak spark can show up on hot motors also, bad idle and you can loose top end, the spark starts to break down at higher RPM's (above 3500).

Water in your fuel will also cause this, but that is usually a winter issue and not a summer issue. Unless your local supplier is watering his gas, some do, they add water and alcohol. I've had it happen to me, there are some gas stations I avoid.

Boom1699 · Jul 11, 2013

it has long crank time the injectors are from a dodge neon(came that way when i bought it) and i just changed the plugs havent done anything else

Boom1699 · Jul 11, 2013

i also made a custom cold air intake

Jays siik xj · Jul 11, 2013

Boom1699 said:
it has long crank time the injectors are from a dodge neon(came that way when i bought it) and i just changed the plugs havent done anything else

Could also be your battery... I noticed when it got below 32* the next morning my jeep would crank and crank really slow but was fine when warm... I changed out my battery and boom... perfect

joe_peters · Jul 11, 2013

Jays siik xj said:
Could also be your battery... I noticed when it got below 32* the next morning my jeep would crank and crank really slow but was fine when warm... I changed out my battery and boom... perfect

Agree.

A battery, fully charged and load tested, is the best starting point, followed by clean cable ends--both ends of each cable.

Check the battery voltage between the terminals STATIC, then CRANKING, then with the engine running. Post up your numbers.

After you have done the electrical, then run a fuel pressure test, and then check how long the system maintains pressure with the key OFF--you need to watch the gauge and record time/pressure drop. Post up those numbers too.

Boom1699 · Jul 12, 2013

Ill get those numbers posted in a few days I'm working out of town for the next few days

Boom1699 · Jul 12, 2013

And when I say cold I am referring to engine temp

jeep slow to start when cold

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