99 sierra studdering

Im have trouble with my 5.3L 99 gmc sierra hesitating as i accelerate. I bought it 5 months ago with no problems what so ever. When I start driving with it cold it studders really bad but smooths out a bit when its at full operating temp around 205deg. Ive replaced the fuel filter, air filter,plugs, and wires with no result, checked the fuel PSI and it has 57PSI at Idle and around 70Psi under a load. I took it to the dealership and they said it needed a fuel rail flush that would cost $190. I took it home and took the fuel rails off myself and they were perfectly clean. What I think is really weird is that there is no check engine light when this hesitation occurs. ITS GOT ME STUMPED!!! Anyone with any suggestions PLEASE Suggest!!

Your engine has multec2 injectors, they can get plugged and cause a hesitation on acceleration.
There is a procedure for cleaning them that is covered in a TSB..it is a labor intensive process and probally the reason the dealer wanted to charge you 180 bucks.

Now before you run down to the local autoparts store and buy some injector cleaner, let me tell you that cleaners and other fuel injection services not listed in the TSB will not clean the injectors properly and some of the chemicals in aftermarket injector cleaners may cause damage to the injector windings.

Your engine has multec2 injectors, they can get plugged and cause a hesitation on acceleration.
There is a procedure for cleaning them that is covered in a TSB..it is a labor intensive process and probally the reason the dealer wanted to charge you 180 bucks.

Now before you run down to the local autoparts store and buy some injector cleaner, let me tell you that cleaners and other fuel injection services not listed in the TSB will not clean the injectors properly and some of the chemicals in aftermarket injector cleaners may cause damage to the injector windings.

Whats a TSB???

Technical Service Bulletin

Technical Service Bulletin


Where is this bulletin? I think I have the same issue.