5.7 Vortec hard time starting in the cold!

[mr98z71]

Over the past summer, I spent over $1000 on a tune up for my truck. My first winter with the truck (last winter), the truck had such a hard time starting in the 40 below weather we have here in Winnipeg, MB. I installed a 2nd battery but the truck would kill two 1000 CCA Battery's without even trying to fire. (The F150 beside me at work would start after the 3rd crank, put me to shame)!

Anyways, this summer, I gave her a tune up, all new parts:

Distributor
Wires
ignition coil
AC Delco Spark Plugs
Updated injectors
intake manifold and plenum gaskets
Fuel Filter
Cleaned MAF Sensor
oh, and Long tube Hookers!

Now that winter is getting closer, it is already spitting and farting at -3c.

What is left to do to this truck? It shouldn't have a hard time starting at this temperature, my carbed Harley even started no problem!

Any help would be much appreciated, I don't want to be asking for a boost all winter long again. By the way, it also recently got a Black Bear Tune.

 

[1997chevydriver]

Block heater? If you have one use it

 

[skylark]

Have you checked the coolant temperature sensor for the ECM? It is the one by the thermostat. If the range shifted an it thinks that it is 70 when it is 0, your going to have problems.

 

[michael hurd]

What is left to do: First and foremost I would check for adequate fuel pressure even though you have the updated spider, if you have low pressure you would get a piss poor atomization. Second, are you certain the distributor is set correctly? I hear there are only a handful of scantools that will work for checking and setting the timing.

Next, clean the cables and verify you have 12.6V at the battery before cranking over. If it is cranking slow because of a bad connection it may not start.

Third... if it starts with plugging the block heater in, you may have a temperature related issue. ( a wire broken inside the outer jacket is a possibility, or a sensor that is not reading in cold weather )

Does it attempt to fire at all in cold weather or just crank like it's not getting fuel and spark>?

A compression check would also be a good idea, you may have a few cylinders low on compression. ( leaky valves / cyl out of round / wear / sticking rings )

If it has properly atomized fuel, half decent compression and proper timing / spark it MUST start.

Could be a faulty ignition module even. ( solder joint issue inside )

Start there and report back with your findings.

 

[mr98z71]

61 PSIG coming from the pump, Coolant temp Sensor measures out fine according to my GM service manual, Distributor is set to 0 +-2, Very good connections going to and from the battery, plugging it in does not make a difference (although the block heater works). In the winter, it will crank about 20 times, fire once, crank another 4-5 times fire once again and keep on doing that until it starts. My Spark plugs were gapped to factory spec, I believe that was 0.60.

I have not done a compression test but I should I guess. I went through the GM service manual and they don't tell you much of what you can check so any advice from you guys would be much appreciated! I rather rectify the problem now at -10 then at -35 outside in the wind!

Jo-eL

 

[michael hurd]

If it gets cold and doesn't start, I would have someone crank it while you check to see if there is spark.

 

[mr98z71]

The Funny thing is though, If I Hold the key to the start position until it actually starts, It will take a while for it to start and it will sputter while attempting to fire. What I did this morning was turn the key to start and let it go after a second (even though it didn't seem like it was firing or going to start) and the truck started with no problems. Could it be that my starter is turning to slow or to fast and keeping the engine from starting? I've never seen anything like this.

 

[michael hurd]

Ignition switch? The contacts can get burned after years and years of starting.

I had a similar issue on my 1991 Honda Civic years ago, where it would stall randomly, but you could re-start it, and the moment you let the key back from the start position, it would stall again. Once the problem got worse, I figured it out, if you let off from the start position just enough, it would stay running, but between the normal run and start positions.

Changed it out with another, it was good to go. Sounds like it may be cutting spark and / or fuel while cranking.

Repeat what you tried this morning and see if that works again.