Suburban won't start when it's cold

My '02 suburban won't turn over or start when it is cold outside. After it warms up outside it will crank right up. Dealer thought it was a problem with sensor not thinking it was in park and changed that part out. That didn't fix the problem. It still won't start. Very frustrated. By the time it gets towed into the dealership it starts right up for them and they can't troubleshoot it. Any suggestions as to what the problem would be? Is this at all tied to the fuel tank problems?

My '02 suburban won't turn over or start when it is cold outside. After it warms up outside it will crank right up. Dealer thought it was a problem with sensor not thinking it was in park and changed that part out. That didn't fix the problem. It still won't start. Very frustrated. By the time it gets towed into the dealership it starts right up for them and they can't troubleshoot it. Any suggestions as to what the problem would be? Is this at all tied to the fuel tank problems?


I stumbled onto this sight while trying to figure out why my wife's 2002 Suburban won't start in the morning, but starts immediately in the afternoon. (It just started doing it this week.) I am curious to see what you find out. Good luck.

I temporarily fixed this problem by loosening the gas cap and leaving it loose. Fired up this morning when normally it would not.

How cold are the mornings ya'll are talking about and what states?

North/Central Texas. Cool mornings would probably be a better choice of words.

When was the last time you changed the fuel filter? Also try replacing the fuel cap.

did the dealer pull any codes off the OBD II? Does it not crank at all in the mornings? Do the lights work in the mornings even if the car doesnt start?

Does anyone know anything more about this? I've been having a similar problem with a 1999 Suburban, where it would sometimes not crank when i turned the key, always during cool weather. After a couple trys it would eventually enage and start. It's been below freezing for the last few days and it won't start at all now.

You did not say for sure what engines. But one thing for sure the fuel pressure has to be up to specs for yyour engine and engine code or the injectors will not squirt fuel cold. Even severl lbs low will make a no start cold.

Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
A few engine have different fuel pressure specs.
But here is the guide lines for fuel pressure testing.
Most Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.
MT

Might try giving a little throttle while starting.

I will add this, my problem is with cold start only, I will crank for 6 to 10 seconds and then it will start, at warm temps (above 50 degrees) it will start with just a touch of the starter. The following was done in steps without a change in the results. I have changed the fuel pump, filter, fuel pressure regulator, complete tune up (plugs, wires, cap, rotor, new duel batteries, had timing checked and distributor gear checked) the fuel pressure is 58 PSI (seems low by my book). will raise to 79 psi with return line shut off. Code reader does not get a code. some times I get a O2 code but it points to the exhaust (it has a 2 1/2" MAGAFLOW system) Sorry for the long list everyone,
Hey MT-2500 what do you think. You helped me out before.

I will add this, my problem is with cold start only, I will crank for 6 to 10 seconds and then it will start, at warm temps (above 50 degrees) it will start with just a touch of the starter. The following was done in steps without a change in the results. I have changed the fuel pump, filter, fuel pressure regulator, complete tune up (plugs, wires, cap, rotor, new duel batteries, had timing checked and distributor gear checked) the fuel pressure is 58 PSI (seems low by my book). will raise to 79 psi with return line shut off. Code reader does not get a code. some times I get a O2 code but it points to the exhaust (it has a 2 1/2" MAGAFLOW system) Sorry for the long list everyone,
Hey MT-2500 what do you think. You helped me out before.

Fuel pressure is to low should be 65 lbs on a cold start.
If under 62-63 lbs the injectors will not squirt cold.
Sounds like fuel pressure is not holding good.
Is that 58 lbs you are getting running or starting pressure?
MT

MT
That is starting pressure, running pressure is much lower, as I said right now I do not have the problem as profound as the weather is warmer. This looks like the fuel pump. I do still have the one I changed out. I had some corrorded wires in the connectors but I changed out the pump at that time as the tank was down. Guess I will have to do this again. Do you recommend a manufacturer better ther the other for a new pump.

thanks FLHT

MT
That is starting pressure, running pressure is much lower, as I said right now I do not have the problem as profound as the weather is warmer. This looks like the fuel pump. I do still have the one I changed out. I had some corrorded wires in the connectors but I changed out the pump at that time as the tank was down. Guess I will have to do this again. Do you recommend a manufacturer better ther the other for a new pump.

thanks FLHT

Gm oem is good but high.
I use a lot of after market pumps but always the good grade ones.
But first if the pump puts out 75-85 lbs of pressure with the return line pinched the pump is good.
The fuel regulater controls the pressure without return line blocked.
Also watch for a fast leakdown. If a fast leakdown you have a leak someplace.
Also make sure the wiring connector to fuel pump is good.
If the pump is not getting good voltage or ground it will lose pressure.
Good luck
MT

I was so frustrated, cause i got this problem; suburban wont crank when is cold outside, after temperature reaches 50 to 55 starts normally, i change the starter but not fix the problem, this is what i did and it worked for me, after several tries, 15 to 20 times, i loose the gas thank cover, and i the truck started right away, i was laughing like a crazy. I don't how this happen but it worked for me.

I'm so glad I found this forum! I was having the same problems with my Burb, thanks people!