91 Laredo

My 94 Sport 4.0 Auto sits overnight and seems to have trouble starting. It almost sputters to a start and sometimes feels like it wants to die. I thought it was just during really cold weather, but its getting warmer out and is still doing the same thing. After its warmed up it fires up almost immediately.

This is what I have done already -

Plugs
Wires
Cap / Rotor
Fuel / Air filters
O2 sensor
Seafoam
Removed and cleaned throttle body and IACV valve

I thought about running some Lucas through it as well next time I fuel up, its been awhile since the Seafoam was run through. I also use Chevron fuel regularly which doesnt seem to have any positive effect.

Any thoughts? Again, it only seems to do it when the engine is cold. I was thinking maybe

MAP
TPS
Leaky fuel injector(s) causing it to flood itself out when cold

They call me cowboy

have you put any thought towards the fuel pressure regulator?

crashzx6r

i would think maybe fuel pump....maybe not enough pressure to start....how does it run once it cranks?

89Cherokee

I am not sure if there is a way to test this but could it be the ignition coil?
I am having similar issues and was thinking about upgrading my jeeps coil to MSD - i would thinking about using the marine version for the waterproofing

I used to have a durango and went through 2 coils in like 6 months (bad location right next to the mech fan (whenever it rained the coil would get splashed with water and crack the housing)

91 Laredo

Yea, I thought about the fuel pressure regulator too....

It runs fine once it starts. It seems to idle a little rough but I think its normal as the tach reads right at 700 and is solid. I've read that hard starting when warm is a sign of fuel pump failure, not cold.

I think the coil is original, didnt see any paperwork for it.

I dunno, this morning when I left work it seemed okay so its kinda sporatic.

91 Laredo

Update -

My Jeep sat for about 3 days and I started it yesterday and fired right up and ran flawlessly. Started it this morning to leave work and seemed fine.

Started it today sputtered for a split second and stalled immediately. Attempted to restart and it cranked for at least 10 seconds before it finally sputtered to life.

Any other ideas based on this new info? Why the hell is it fine for one start and barely fires on another?

I guess I will pick up a gauge and give that a shot.

I need to get this figured out before I find myself at a Toyota dealer eyeballing some 4runners's. (Sorry, but I had to say it to scare the Jeep)

solderjunkie

Be sure to say it in the Jeep's presence... threaten to buy a Toyota, then sell the Jeep to a housewife who will use it to haul kids to soccer.

That'll fix it

(or it will do like mine and catch fire in the middle of the night)

MarineScott

Have a look at your ECT(engine coolant temperature sensor) and check to see if it is within specs

91 Laredo

Really? Never thoght of that. How do you test it?

It started better this morning, but still died immediately on the first crank. Tried it again and it started in a few seconds.

To me it feels like a starving carb where if you dont pump the throttle when you start it dies. Makes me think its something to do with fuel.

Dunno, we'll see how it goes after the fuel pressure is tested and if thats okay I may take it into a shop before shotgunning repairs.