cold temps = hard or no start

[92tank]

ok so i have a new problem with my stroker as of the sunday it dont like to start when its below freezing, or if it does it take a long time like its flooding out (smell gas). i thought it was the coil cuz i sprayed the dizzy side with water and when i got to the coil it died. so i changed it. started fine tuesday and wednesday, but when i want to start it this morning to go coyote hunting it would not start again. i popped and sputtered a little, so i grabbed some starting fluid and gave it a shot and it started and fine havent had any problems all day. the fuel pump comes on, its got a new coil, cap and rotor were new this spring, along with plugs. so my question is what is going on?

[Missourian]

First, how old is your fuel pump? Regardless of hearing a fuel pump operate, it does not mean that you are always getting the pressure/flow that you need to operate the engine. Fuel pumps typically fail intermittently before a complete failure.

Secondly, have you put any HEET (or other fuel moisture/water remover) into your fuel tank to remove moisture... you could have water in your fuel, fuel filter and it is taking some flow to break it down. As fuel passes by and through ice it melts the frozen water.

Hopefully, it is as simple as water in your fuel lines/tank.

[cruiser54]

The starting fluid is a clue. You need to do a fuel pressure test. That old fuel pump may not like the cold. Missourian's advice on using Heet in the tank is good also.

[racing89]

No start , cold start only and once it starts its good for all day? If u checked it by the book you will probably find that you have no fire AND no injecter pulse. If so, you need an ecm. Dont know exactly why, but I assume its a processing issue with the crank and or temp.signal. Very common on 91-95 4.ol jeeps.

[92tank]

well i am going to put some heet in the tank when i fill it back up. and it doesnt do it all the time. it started just fine today. what gets me is once it starts its fine and runs great, no issues at all. as far as fuel when i push the valve on the fuel rail i get a normal squirt (compared to the other jeeps i have) not sure on pressure though as i dont have a gauge. when it does screw up it starts popping like it only fires on one or two cyl at a time then finally starts.

[SilverXJ]

Get a fuel pressure gauge and attach it before a cold start and see what it does. You could also try turning it on and off 3 or so times before you start it to prime the fuel rail. The rich smell doesn't necessarily mean its flooding. A lean misfire will also cause a rich smell.

Also, check the TPS, coolant temp sensor, air temp sensor and MAP sensor.

[racing89]

No start , cold start only and once it starts its good for all day? If u checked it by the book you will probably find that you have no fire AND no injecter pulse. If so, you need an ecm. Dont know exactly why, but I assume its a processing issue with the crank and or temp.signal. Very common on 91-95 4.ol jeeps.

s.b.e.c., Computer, brainbox, ecu, powermodule., s.m.e.c., whatever u want to call it, u probably need one. Im not just guessing, but basing my suggestion on past experiences as a licensed automotive technition(red seal), jeep owner and racer, and salvage yard manager(sold 2 ecm's last month for this COMMON complaint).

[SilverXJ]

Your jumping a bit ahead there. There is nothing that indicates its the PCM yet.

[92tank]

it started fine agian today and i filled her up and put some heet in with the fuel so im hoping that takes care of it. it either that or my jeep is just being a lazy A$$ and only starts when IT wants to.

[92tank]

well it did it to me again yesterday, so today i pulled the dizzy cap and it was all green in side so i changed everything cap, rotor, plugs and wires. hopfully that fixes it as we are leaving town tomorrow. i have my tools with me and a good spare ecm so if that happens to be it i can change it. but i dose seem to start and idle a little smoother. btw it was almost two years since cap & rotor were changed last.

[racing89]

Fixed?

[gmakra]

One thing that hasn't been discussed here is the IAC (idle air controller) which helps with cold starting. Take a look and and see if the pintle is fouled and clean with carb cleaner chances are is original.

[92tank]

so far so good, cant say for sure its fixed yet as it didnt do it the time but it hasnt since the tune up. and the IAC was cleaned about a year ago when i bored out the throttle body.

[woodjeep]

The 92 fuel mixture is based upon the temperature of the coolant as sensed by the temp sender in the thermostat cover. If it thinks the engine is already warm...it drastically cuts back fuel. Alternately...it will add extra fuel when the coolant is cold to help warm up the engine . I know this because I have a 2200 ohm resistor in parallel with the variable resistor in the tstat coolant temp sender. This extra resistor is tied into the system with an on/off switch. When my engine is warm and I turn it on...it fakes the computer into thinking the engine is about 20-30 degrees warmer than it actually is. It will turn on the aux fan at around 200 instead of 220 for driving in traffic and it also leans out the fuel mix for better economy. If I leave it on accidentally in the winter and the car is cold...i can't start it. This may not be your problem but it does effect starting in the cold and is difficult to diagnose without a multimeter. Somewhere I have a chart that gives approx resistances for approx temps