Questions about Injectors

[TahoeBoy919]

I recently came to own a 99 Tahoe with the 5.7 Vortec, The truck has only 150,300 miles on it and runs beautifully. As of recently on occasion the truck takes quite a few cranks to start her up, and when I put her in drive she is sluggish untill i add enough gas, almost like the feeling I've got in an old truck when the fuel pump went out.

The fuel pump and filter were changed 6 months ago, and a family mechanic says it might be the injectors. I was wondering if anyone here has encountered this before and if so what the problem was, I would like to not have to replace 800$ worth of parts if it wont fix my problem.

 

[95TwinTT]

It is highly unlikely that all of the injectors took a dump at the same time. You might want to try turning the ignition on, but wait a few seconds until to turn it all the way to start. Give the fuel pump a few seconds to get the sauce up to pressure.

If that makes a difference on how long it cranks, I would look in the direction of the fuel pressure regulator.

 

[General Stalin]

Well, tkaing a few cranks to start up and the acceleration thing could be unrelated. The slow starting could be an electical ignition problem or something. Do you have a check engine light at all? Your hesitant acceleration could be a sensor issue. Maybe EGR valve or O2.

You can get your fuel pressure checked, and check to make sure none of the injectors are clogged.

 

[TahoeBoy919]

I haven't checked my regulator, there is no check engine lite and the truck only has a problem like 1/4th of the time. Once it gets going ( me adding enough gas) it seems to pick right up and go. The mechanic I had look at it said he was almost positive it was the fuel injectors, he is getting the whole assembly and 8 injectors at cost ( 300 for parts plus 100 labor) is it worth trusting this guy and seeing if it fixes my problem? or is there a way I can test the fuel pressure regulator? ( I am not new to cars but new to big engine trucks)

Thanks

TahoeBoy919

 

[GMCYukalade]

if it where the fuel injectors, you would be throwing a mis-fire code.. Do like what was previously posted, - prime the system - first, turn the key on, give the fuel pump time to stop sounding, than turn it off, turn it back on, let it stop sounding again, turn it off, turn it back on 1 more time, and let it completly stop sounding again, than turn the key to crank it.. see if that has any differeance on it - if not, than it is probably regulator related

 

[NoEcm]

I haven't checked my regulator, there is no check engine lite and the truck only has a problem like 1/4th of the time. Once it gets going ( me adding enough gas) it seems to pick right up and go. The mechanic I had look at it said he was almost positive it was the fuel injectors, he is getting the whole assembly and 8 injectors at cost ( 300 for parts plus 100 labor) is it worth trusting this guy and seeing if it fixes my problem? or is there a way I can test the fuel pressure regulator? ( I am not new to cars but new to big engine trucks)

Thanks

TahoeBoy919

If you do decide to replace the injectors, do the MFI upgrade. Cost should be around the same. Google TSB 00-06-04-003B for additional information.

 

[skimo]

I had 2 fuel injectors go bad but there was a constant "pinging" and bad sound all the time . It never got better. I have had my fuel injectors cleaned and it helped(when they were good). Cost me $500.00 to replace those two.....Check the fuel filter underneath. Had mine changed and you wouldnt believe what came out of there...made a big difference with new one..hope this helps....

 

[Budreau68]

Cap/Rotor/Tune-up

When was the last time you did a cap/rotor/spark plug/wires/tune-up? Could be that simple. Could be a cold start valve/vacumn advance/whatever they use issue. Or is it the new distributorless ignition?

It only happens 1/4 of the time, is that only when the truck is cold? Do you tap the gas before starting the ingnition or when you get in/out of the truck? That could be releasing the pressure in the line.

I agree that it doesn't sound like an injector issue. More like a fuel pressue/spark issue.

 

[GMCYukalade]

I remember on the older Camaros when they first started coming out with fuel injection the sticker on the windows when they were on the lots said Do Not Press The Gas Pedal When Trying To Start Vehicle

 

[JennaBear]

It may be in the injectors, but that is an expensive guessing game. It really needs to be looked at by somebody with the proper equipment to scan the computer. It would be wise to spend a few extra dollars on diagnosing the problem rather than a couple hundred on random guesses.

 

[amack23]

The prime-up procedure worked for me. At least it'll buy me some time. You all are great...!!!!