Start up problem

DeiselRed · Post by **DeiselRed** » Thu Aug 20, 2009 8:09 pm

Recently when I last filled up my tank with gas and let it sit for about a couple hours, I get into my truck to start it and it is taking an awfully long time to fire. This is the second tank that has started to become like this. However, I did throw octane booster and a FI cleaner into my last tank which did make a diferance near half-end of the tank. It is pretty hot and humid here in CT and I was wondering if possibly the weather may have to deal with it? I have been using 87 for a while and have never had any start up issues

Any Ideas would be much appreciated.

Matt

Post by **HenryJ** » Thu Aug 20, 2009 8:30 pm

Hows the fuel filter? More than 15k miles on it?

F9K9 · Post by **F9K9** » Thu Aug 20, 2009 8:39 pm

Another temporary cure is turn the key to "run" but, not crank the engine for 10 seconds or so. If, it starts on the second try faster then, it is time to listen to Brule.

Post by **HenryJ** » Thu Aug 20, 2009 8:45 pm

You thinking a new pump is in his future?

(me too)

He is probably leaning toward leaky poppets, but these are not as known for dribbling. That is a CPI thing. The complaint would have been misfiring on an SFI engine.

I think the next step after the fuel filter is to go through the fuel system tests to narrow it down.

JaVeRo · Post by **JaVeRo** » Thu Aug 20, 2009 9:55 pm

Put a pressure gauge on it, turn on the key but don't start it. The pressure will come up when you turn on the key. If the pressure drops off rapidly after the pump cycles on then off, you have the same problem I do.

When you figure out what is causing it, let me know. I don't have a clue.

James

F9K9 · Post by **F9K9** » Thu Aug 20, 2009 10:18 pm

HenryJ wrote:................I think the next step after the fuel filter is to go through the fuel system tests to narrow it down.

I am sorry, you're absolutely correct. I am starting to confuse different flavors of vehicles.

The filter and pump is pretty much a combined problem on some rigs. We should actually be grateful at our filter's location.

Post by **HenryJ** » Fri Aug 21, 2009 4:50 am

JaVeRo wrote:When you figure out what is causing it, let me know. I don't have a clue.

Here's your clue: Fuel System Diagnosis , Testing fuel pump

DeiselRed · Post by **DeiselRed** » Fri Aug 21, 2009 5:54 am

Thank you for the info guys.

Post by **HenryJ** » Fri Aug 21, 2009 6:49 am

Do the easy stuff first. Check the ignition components, cap rotor, plugs. Air cleaner. Clean the throttle body.
All the basics. That gives you a clean slate and good starting point.

DeiselRed · Post by **DeiselRed** » Fri Aug 21, 2009 8:22 am

Thank you. You guys are very helpful. Will keep you updated.

barch97 · Post by **barch97** » Fri Aug 21, 2009 9:28 am

I can certainly understand how the recent additives have got everyone thinking fuel system but start up issues always make me suspicious...

killian96ss · Post by **killian96ss** » Fri Aug 21, 2009 10:26 am

When my Crew Cab did the same exact thing, it turned out to be leaking injectors. GM replaced the old SCPFI system for free with the newer MPFI system.

Sequential Central Port Fuel Injection to Multi Port Fuel Injection Upgrade

Steve

roadrunner · Post by **roadrunner** » Fri Aug 21, 2009 2:44 pm

Could be fuel system and well worth checking out but Barch has a good point. Had a cap failure not long ago that drove me nuts. Acted like a wet cap complete with cross-firing symptoms. Cap was near new. Replaced rotor ran good. 2 days later same problem replaced cap and all has been well since. No obvious carbon tracks or other defects could be found on cap that caused problem.

rlrnr53 · Post by **rlrnr53** » Fri Aug 21, 2009 4:17 pm

It may be possible that the computer is not giving the command to start the fuel pump, and it is starting when the engine builds oil pressure. I've had this problem on other GM vehicles. the easy check is to have some one turn the key on while you listen (with the fuel cap off) at the fuel filler.

Horsehammerr · Post by **Horsehammerr** » Sat Aug 22, 2009 1:58 am

I can hear my pump come up to pressure sitting in my cab. I simply turn the key to full on and listen for the pump to stop, crank the motor and away we go.

killian96ss · Post by **killian96ss** » Sat Aug 22, 2009 11:36 am

Hearing the fuel pump does not mean that it is making good pressure and holding it.

In order to rule out fuel related problems you need to do a pressure test with a guage. The test guages that have an air bleed valve are more accurate than the others. Check the fuel pressure before the engine starts and after.

Steve

DeiselRed · Post by **DeiselRed** » Tue Aug 25, 2009 6:21 am

But also my issue is that its about a 50/50 chance of the starting up problem. Thats why I was leaning towards more of spark plugs/wires and such like that. If it was a fuel pump or injectors wouldnt it always have problem starting up?

Post by **HenryJ** » Tue Aug 25, 2009 6:57 am

Not necessarily. Both can be intermittent. Do the tests , that will tell the tale.

DeiselRed · Post by **DeiselRed** » Tue Aug 25, 2009 10:14 am

Yes sir, Thursday the results will come in. My theory is that I actually ran my truck very low on gasoline by accident a couple weeks ago. I think I could have damaged my fuel pump or burned it out because I was so low, (under a galon in the reserve) untill I got to the gas station. So that's my theory. Deffinatly not bad gas because I threw 93 into it about a full tank!! God what a difference in performance compared to 87 though! And when it does start, It almost wants to die out and slowly come to life. I think im just not holding enough pressure at start. But thank you Henry J for everything. You are the S-10 God

Post by **HenryJ** » Tue Aug 25, 2009 10:47 am

You might need to change that fuel filter again. Sometimes you suck up all the garbage in the bottom of the tank when you run that low.
It would be worth changing before you condemn the fuel pump.

DeiselRed · Post by **DeiselRed** » Tue Aug 25, 2009 12:14 pm

I will do that Henry J. But I will have the fuel pressure test just to be in good measures

. I will keep you updated

Edit: Fuel Filter is getting installed tommarow by myself and a friend. Will let you know if that is the cause.

kwalsh · Post by **kwalsh** » Tue Aug 25, 2009 6:57 pm

If you're approaching 100k miles pay attention to the fuel pump as a potential issue. My pump died around 120k but it was acting up for quite some time (months). The truck wouldn't start on the first turn of the key. It would turn over on the 2nd turn of the key.
I also did exactly what HenryJ suggested, new plugs, wires, cap, rotor, fuel filter. At first I thought it was advanced corrosion on the distributor so I removed the vent screens.

I had the buzzing sound from the fuel pump the entire time until one day.....silence. dead fuel pump

Good luck

DeiselRed · Post by **DeiselRed** » Wed Aug 26, 2009 6:59 am

If the fuel pump is an issue. That will be determined tommarow once I get a fuel pressure test done. For now, I am doing my fuel filter today. Im leaning towards a bad fuel filter or pump still though. We will see what the results give. I will get to the bottom of it!

Matt

DeiselRed · Post by **DeiselRed** » Wed Aug 26, 2009 2:24 pm

Fuel Filter was done today by me and a friend. And I Can say that the entire contents in my filter was completly black. I honestly think that was the stock filter that it has ever had because it was a BI*** To get off. The last 4 start ups have been clean and crisp. I think it has been resolved. I will let you know if the problem does arise again within the next day or two.

Matt.

Post by **HenryJ** » Wed Aug 26, 2009 2:25 pm

I think you found your problem.

kwalsh · Post by **kwalsh** » Wed Aug 26, 2009 5:32 pm

That's great news! It's a lot cheaper and easier than swapping out the fuel pump.

DeiselRed · Post by **DeiselRed** » Thu Aug 27, 2009 6:26 am

Haha yeah it is. And even then I am under a extended 3 year warranty when I bought the vehicle. And Yep I think the problem is solved. Thank you for your guidance everyone

DeiselRed · Post by **DeiselRed** » Sat Aug 29, 2009 4:09 pm

Back to the drawing board. Start up's became weak again and taking long time to fire while cranking over. I was an idiot and cancled my appointment to get a fuel pressure test done because I thought i solved the problem. Now I have to wait untill monday. Will post results of the test.

Post by **HenryJ** » Sat Aug 29, 2009 5:16 pm

They have these stores that sell fuel pressure testers. Around here they are called Auto parts stores.
You can probably buy a tester for less than a shop will charge to test it for you and you will probably do a better job by following the directions we have posted.

If you can air up a tire, you have all the skills needed to attach the fuel pressure gauge.

Think about it. You might even be able to help someone else someday. Tools are never a bad investment.
There may be stores that will rent the gauge too?

Horsehammerr · Post by **Horsehammerr** » Sat Aug 29, 2009 5:33 pm

You really are a CLASS ACT Brule !!

DeiselRed · Post by **DeiselRed** » Tue Sep 01, 2009 9:40 am

Ended up doing the test today. Looked over a few things. And after I did everything as shown I figured it out. Fuel pressure regulator. Problem solved.

killian96ss · Post by **killian96ss** » Tue Sep 01, 2009 11:07 am

DeiselRed wrote:Ended up doing the test today. Looked over a few things. And after I did everything as shown I figured it out. Fuel pressure regulator. Problem solved.

How did you determine that the regulator is the problem? What were the test results with the key on engine off, and with the engine running?

Steve

kwalsh · Post by **kwalsh** » Tue Sep 01, 2009 5:17 pm

Did you bypass the regulator to determine it was faulty? Could you share the troubleshooting methodology?

Post by **HenryJ** » Tue Sep 01, 2009 5:23 pm

It is all in the Fuel diagnosis link above. That checks, pump, regulator, etc.

kwalsh · Post by **kwalsh** » Tue Sep 01, 2009 6:01 pm

Copy. Thanks Brule, I'll check it out....missed that one....