Truck starts very hard or not at all when cold

Sounds like low fuel psi .try changing fuel filter

You need to run a fuel pressure leak down test, the fuel pressure test port is on the engine in the pipe that sits over the fuel injectors and supplies them fuel. You will need to buy or borrow a fuel pressure test gauge. Hook up the gauge and turn the keu on, make sure you have no leak at the connection point of the fuel pressure test gauge, then shut the engine down, watch the gauge, the fuel fuel pressure should not drop more than about 3-5 PSI, if it goes down more than that you have a defective fuel pump.

Have you changed the spark plugs for new ones?

89 has the old stand alone spark distributor.
the ECU is spark free, (no player here)
so here is the list for this engine 1.3 or 1.6L
the 1.3 has a carb. (last one) and is NOT EFI ,
you never said which engine it has. so ill guess at the 1.6L
This engine will have hard starting for the fooling reasons.
we dont guess at it we just do the tests.

• Bad fuel.
• Never tunedup this decade or every 60,000 miles per opr. guide.
• low engine compression 150 good, if all are very low the cam timing belt slipped., (they all do , ignored) and is 60k service point.
• CEL dead key on, bad ECU or lamp bad.
• CEL glowing running, its telling you what is wrong, get the flash codes (DTC's)
• Too high fuel pressure. (bad regulator in front of TB)
• ECT bad. the 2 pin engine coolant temp sensor is bad. test it.
• The injector leaks in the throttle body (look with eyes)
• You find that adding 5-10% throttle cranking makes it more easy that is a bad, IAC valve, the valve at the base of the throttle body is stuck closed and kills all cold start air supply. making cold starts very hard, unless tricked with right foot. yes?
• when any gas engine fails to start cold, i check for too much or too little starting fuel. and for very good spark.
• Good engine, good spark the good fueling, there are tests for each, ASK?

4.3L V6 CPI - center port fuel injection . you need 62 psi .When cold give it a shot of carb.cleaner or starting fluid ! does it start then ?

415-455 kPa (60-66 psi

try starting with gas pedal to floor to shut off fuel during cranking to see if flooded. rule that out first.

Hello,
The car may be hard to start because it may need a normal tune-up. If the spark plugs are pretty used, they will slowly stop burning as much fuel because the spark slowly gets lesser and lesser. On a cold day the fuel is harder to ignite with a small amount of spark.
Normal idle when its cold means that your cars idle is probably too high. If you lower the idle, the choke on a cold day will keep the idle a little higher until the motor warms and then it will kick back off. If the idle is too high, it will run very rich, smothering itself with fuel, and causing the idle to stay low. When the car warms, its creating better spark when its warm, and with the idle being too high its running at a fast idle.
The car wont start sometimes can be the cause of a few things. If the ground is bad on the fuel pump, it wont make a good connection sometimes for when you turn the key on, the fuel pump dont pump the fuel to the engine. Another one can be that your accessory switch can be loose going to the fuel pump. I think its your ground though. Good luck! Hope this helps.
Have a nice day. -Steve

have u check you spark plug and leads make sure they are not worn out(or when was the last time you change them).or your injector could be block u should get some injector cleaner and pour it in your fuel tank when your next fill ( or get some one to clean them out $30 per injector)

If the pressure is slow to rise, you should consider changing the fuel filter if it has not been done in the past 30,000 miles.
Next, disconnect a spark plug and check for spark while engine is cranking. Use a spark tester or old spark plug grounded to the engine block.
Let me know.
Regards,

Sounds like your fuel pump is going out on you. Check your fuel pressure. You should have 40 psi when the key is in "on" position. You should have no less than 5 psi under that when it's running.