Weird starting routine

[Baythan]

Truck gets started once a week regardless of whether I'm taking it somewhere. Lately, it's been doing this:

Get in truck, turn key. Turns over, but never fires.

Turn key off.

Turn key again and it starts right up.

Same thing every time.

Battery is brand new, btw. Idles and runs fine.

It's going to Bob Bigtime soon, but I just wanted to get some ideas (no time to search the vast posts on "starting" problems.)

So, fuel line issue, ignition, starter???

 

[Tophatjimmy]

Re: Weird starting routine

mine does kind of the same thing.

Key in and crank......will start after 7-10 seconds of cranking.

Key in and crank for 2 seconds, ign off, crank again.....fires right up.

Weird.

 

[Baythan]

Re: Weird starting routine

mine does kind of the same thing.

Key in and crank......will start after 7-10 seconds of cranking.

Key in and crank for 2 seconds, ign off, crank again.....fires right up.

Weird.

This is actually encouraging. Means it's probably a standard POS SyTy problem.

Here's how I feel about SyTy's right now: :banghead:

 

[Tophatjimmy]

Re: Weird starting routine

I have a feeling mine might be fuel pump related.....but I'm not ambitious enough to take the bed off till I can buy a Walbro and an AFPR.

 

[Baythan]

Re: Weird starting routine

I have a feeling mine might be fuel pump related.....but I'm not ambitious enough to take the bed off till I can buy a Walbro and an AFPR.

That would be my first guess. Waiting to see what others will say.

 

[Mtn Z]

Re: Weird starting routine

Fuel pump. I'd bet money. First time the pump primes isn't enough to build pressure. That's what my Camaro does right now. Second time you prime it is enough to start it. Go get a Racetronix and an AFPR. :tup:

 

[ilandaze2]

Re: Weird starting routine

i say fuel pump too!

 

[Loeryder]

Re: Weird starting routine

Try this.
Turn key to on and let the pump prime.

Then turn it off without cranking and turn to on again to prime a 2nd time.
Then turn it over.
If it starts after 2 prime cycles I am willing to bet it is the pump as well.

Trucks that sit have a lot more starting problems than daily drivers.
Mine acts different every time have started it lately but it sits in a storage locker that gets to 115 in the heat of the day.

I melted a roll of duct tape to my tool box last week...
Now wtf am I going to use to hold my SyTy together?

 

[Mtn Z]

Re: Weird starting routine

I melted a roll of duct tape to my tool box last week...
Now wtf am I going to use to hold my SyTy together?

Zip ties :tup:

 

[Flyin Ryan]

Re: Weird starting routine

I had the same issue a few weeks back.. that lasted about two weeks of daily driving before it wouldn't start anymore.. Swapped the fuel pump relay with the ac relay and all is well.. So it was the fuel pump relay going out in my case. Worth a shot and it'll only take you 2.5 seconds do to. There the two relays located above the brake booster on the driver's side firewall.

 

[Loeryder]

Re: Weird starting routine

Zip ties

Shit, thats no joke.
The top drawer of my toolbox has at least 3 sizes in 4 colors. lol
and I run out regularly, wtf?

Swapped the fuel pump relay with the ac relay and all is well.. So it was the fuel pump relay going out in my case. Worth a shot and it'll only take you 2.5 seconds do to. There the two relays located above the brake booster on the driver's side firewall.

True, one of the many sources of voltage drop between the battery and the pump.

 

[sy#2921]

Re: Weird starting routine

Do you crank the truck as soon as the pump is done priming? I noticed that my syclone and my s10 both will not fire or will take excessive cranking to catch if I dont not do it as soon as the pump is done priming. I really dont think its fuel pumps in both trucks since they are new this year.

Don added something I forgot about, I have a gauge on the fuel rail in the sy and the fuel pressure is good and doesnt drop during cranking ( had my dad look so keep the impossible to crank and look comments down)

 

[Don W.]

Re: Weird starting routine

I have virtually the same issue. I have FP gauge and can watch the FP come up instantly, first and every time. BUT if I do the key on, key off, prime it, trick a couple of times it fires right up. Since I have FP first time what's going on? I have no clue. I gave up long ago and just crank it for the few seconds it takes to fire. If it has sat for a while it won't light on every cyl either. Hits on one, skips a couple, then a two more, then it lights on all 6. Oh well, seems to run runs fine other wise. Acts like vapor lock but with 40# of FP I doubt it.

 

[sy#2921]

Re: Weird starting routine

Hits on one, skips a couple, then a two more, then it lights on all 8. Oh well

hmm if your syclone is hitting on all 8 I think you have something else wrong :rotf:

 

[Baythan]

Re: Weird starting routine

Thanks. I'll try all of this. The prime trick, relay swap, and eventually, fuel pump.

, skips a couple, then a two more, then it lights on all 8.

Um...did you mean 6?

 

[Don W.]

Re: Weird starting routine

Now that's funny.

Fixed...

 

[SY2932]

Re: Weird starting routine

I have a feeling mine might be fuel pump related.....but I'm not ambitious enough to take the bed off till I can buy a Walbro and an AFPR.

It is, I started having this problem with my truck not long after the Homecoming meet in MI

. Check valve in the fuel pump is shot. I put my fuel pressure gauge on the fuel rail and after I turn the truck off, my fuel pressure drops to zero in less than 2 seconds. As mentioned by others, the "several crank boogie" is required to build up enough pressure in the line for it to fire. The pump itself is fine, fuel pressure still rises 1 psi per pound of boost. I plan to go to fuel cell and external fuel pump in the future so I guess that I will just put up with it rather than spend the money on another in tank Walbro.

 

[Daryl H]

Re: Weird starting routine

I finally fixed mine with new fuel injectors. Drove it like that for 60K.
It would crank right up if warmed driven recently. If cold, it was the long delayed startup.

 

[Jimmy]

Re: Weird starting routine

Just keep cranking it until the oil pressure gauge moves.It should fire right up if its the relay.
GM built in a safe start into the ECM where it won't fire if it doesnt read FP until it sees oil pressure.