Hard Start for the 3.4

I've noticed that my truck has trouble starting up when I'm having to turn it on and off frequently (running errands) for awhile now, I've changed the spark plugs/wires, battery, coolant, and starter. Nothing seems to have changed, it's not a huge problem yet as the truck hasn't not started, but I hate hearing it struggle to turn over and I know it can cause problems if not addressed. Any input or ideas help

 

I've had this in both my 3.4s. Sub'd.

 

Sub'd. Both mine do it too. Since it always starts, never really thought it was a problem, but if someones got a solution I'm all ears.

 

its a well known issue called "hard warm start", what is happening in 98% of the cases is, its one or more of the injectors dripping gas in the cylinders causing a "flooded" condition so it has to purge out that extra gas before starting. in the other cases it can be fuel pump bleeding down losing fuel rail pressure. its normally not a bad enough leak to notice any gas smell in the oil or anything to tip you off that the injectors might be leaking because its only leaking at peak fuel pressures.

use a bore scope on a warm engine and shut it down, pull a plug, then use the bore scope to see if the injector is dry or if it drips gas. repeat test for all 6 cylinders and replace any injectors you find leaking.

 

Mine does it aswell. Seems to be common on the 3.4.

 

Could possibly be the fuel pressure regulator. Usually when these go bad the engine will start normally when cold and crank excessively when warm. As kekar stated it could be injector bleed down as well.

 

Still got this problem on mine occasionally. Cleaning the iac valve helps a little. Planning on changing the pressure regulator. Kinda an expensive part to throw in not knowing if it's the cause. But I'm willing to take it if it saves me money, and a ton of down time messing with the injectors. And possible issues down the road as i might not get true "oem" injectors from eBay when/if I order them if regulator doesn't do the trick. Cuz I sure ain't buying true oems at that price.

 

now when you say you hear it struggling to turn over, do you mean it's turning slowly? that's pointing more towards a low battery voltage issue. your battery could be going bad. your terminals are corroded and aren't getting enough juice over. you may not have enough acid/water in the battery. either way. it sounds like there isn't enough juice getting to the starter

 

If it is turning over just fine but taking a long time to actually start I had that before. I basically turn the ignition on, wait a few seconds and then crank it... this way it has always started up like a champ for me.

--Dan

 

I know this is an old thread but just had this happen for the first time on my new to me high mileage 03 double cab..
Its about 10f out right now...(i know plugging in isnt really necessary)plugged it in to let the block and pan heat for an hr and it started right up as expected. Drove over to a friends and the truck sat about an hr and half...i went out to start it and it took 3 long turns of the igntion before it stumbled to life. When i pulled in to my drive an parked it seemed to run a little rough at idle. I stopped and started it a few times and it started right up like normal and still ran a little rough at idle... the truck does have 239k on it so im not suprised...however it does have new plugs, wires, air filter...the po put 4500 into it just before i bought it(i paid 4500)... Ill fire it up tomorrow cold and see what she does...i have to go to the post office so itll get warm and ill see if it reproduces the symptom..

 

Anyone get any kinda results running some injector cleaner or marvel through the system?

 

Did you do the plugs or the po? How many miles on them?

 

Po had a shop do all the work in one shot...from lower balljoints and cvs to timing belt and water pump. I just noticed when reading the service record it was done at 211k...its at 239k now, so i must have misunderstood him saying it was just done lol....that said it sat for almost a year before i got it.

 

Let’s start with new plugs or put a wrench on them and see if they’re tight, at least

 

Ill agree with that..i had for a second ruled out plugs thinking they were only months old..

 

Mhmm. I don’t trust anything but starting with the plugs seems like a good idea

 

I have had issues even with brand new plugs before(autolite) so i shouldnt have disregarded them...to be honest i dont even know what brand is in there. The shop he took it to maintained it the whole time he had it and they have a good reputation....although their service writer could use a few classes lol.

 

It’s no one’s fault. The plugs worked well… until they didnt

 

I ran a bottle of Lucas fuel injector cleaner after I cleaned the TB and ICV and problem went away. I had that same issue. Hard to start when warm. Not sure what it was. Dirty something maybe?

 

It was the IAC when I had the warm start problem. Gas stations every time. Give it a little gas during crank, and if it starts up easier, that's it.