99 tahoe hard to start

[rdharley3]

my 99 tahoe 5.7 124k when cold starting the first time motor turns over no problem but will not start it usually starts the 2nd or 3rd try It was tuned up about 30k ago new fuel pump 8 mo ago new fuel filter 1 month ago. Any7 suggestions on what it could be?


Thanks,

RDH

[MT-2500]

Originally Posted by rdharley3

my 99 tahoe 5.7 124k when cold starting the first time motor turns over no problem but will not start it usually starts the 2nd or 3rd try It was tuned up about 30k ago new fuel pump 8 mo ago new fuel filter 1 month ago. Any7 suggestions on what it could be?


Thanks,

RDH

How is the plugs and filters. Good hot blue spqark to plugs?
Any check engine lights?
You have to have the correct fuel pressure for a cold start.
Even a couple of lbs low and the injectoors will not squirt.
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.
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.

[rdharley3]

I tuned it up about 30k ago I will check plugs and filters and spark. I've not checked fuel pressure, I will have to purchase a guage and post back the readings.

RDH

[rdharley3]

thanks MT

I was checking my plugs and noticed that one of the plug wires was not seated as a matter of fact ready to fall off seated the plug wire started right up the first time.

RDH

[MT-2500]

Originally Posted by rdharley3

thanks MT

I was checking my plugs and noticed that one of the plug wires was not seated as a matter of fact ready to fall off seated the plug wire started right up the first time.

RDH

You are welcome.
Yes lose wirs can cause problems.
Give it a try for a few days and see if all is well.
MT

[rdharley3]

MT

Just wanted to update on the problem I was having with my tahoe. I thought that the plugwire not being seated fixed the problem, but that only fixed half the problem a few days later the tahoe would not start at all I dumped some fuel in the TB and it started for a few seconds It turns out that the fuel pump was bad after replacing it runs great. I was told not to let the fuel tank get down below 1/4 tank that below 1/4 tank puts considerable strain on the fuel pump is there any truth to that???


RDH

[MT-2500]

Originally Posted by rdharley3

MT

Just wanted to update on the problem I was having with my tahoe. I thought that the plugwire not being seated fixed the problem, but that only fixed half the problem a few days later the tahoe would not start at all I dumped some fuel in the TB and it started for a few seconds It turns out that the fuel pump was bad after replacing it runs great. I was told not to let the fuel tank get down below 1/4 tank that below 1/4 tank puts considerable strain on the fuel pump is there any truth to that???


RDH

Thanks for posting back and letting us all know how it went.
Glad you got it fixed.
And Yes you need to keep gas in it.
A 1/4 or more is good.
If gas level gets low fuel pump can suck air and over heat from not enough gas to keep it cool.
Just remember people that keep gas in there tanks have a lot less fuel pump problems.
Real low or running out can kill a fuel pump.
Good luck MT

[97cavalier]

make shure the fuel filter is not dirty because if it is and you install a new fuel pump, it can cause it to go bad right away. So even if you replaced it a while back, i would replace it again if you put a new pump in.