Hesitation in '99 Suburban 5.7: - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ain't_done_yet · 09-27-2006, 09:06 PM

Need some help here...I have a 1999 Suburban w/113K on it. EVERYTHING has been serviced (that I can think of) but when you get in it first thing in the A.M., it hesitates when you first accelerate (for about 2-4 seconds.) Kind of like it's missing or flooding out. Outside temperature doesn't seem to make a difference. It runs like a champ after that first hesitation. Any help would be great!!!

**N2TRUX** · 09-30-2006, 05:12 PM

When you say "EVERYTHING has been serviced " what does that include? Have you had the injectors cleaned? Rough idle and surging can be dirty or sticky injectors. If you haven't changed your fuel filter try that first. If that doesn't help consider a fuel system flush and injectors clean up.

ain't_done_yet · 09-30-2006, 09:22 PM

Thank you for your response!

I haven't actually had the injectors serviced, but I have been running AMSOIL fuel injector cleaner for about two years now (other brands B4 AMSOIL). The idle is actually smooth, just hesitates when you first accelerate. Also, I've replaced the fuel filter numerous times (WIX), and I have even replaced fuel pump (AC Delco)(that was fun).

I just recently had the trans serviced 'cause the wife said it was shifting hard. I think this is something common on this truck. The trans guy said it was still throwing a code, so I may run it down to my buds at Oreilly's and have 'em check it out.

*bluewhitepete* · 10-05-2006, 08:51 AM

try cleaning your throttle body. sometimes you get build up in there and it can cause hesitation, have you done a full tune up on it lately?

67ChevyRedneck · 10-05-2006, 10:45 AM

Quote:

Originally Posted by ain't_done_yet

Need some help here...I have a 1999 Suburban w/113K on it. EVERYTHING has been serviced (that I can think of) but when you get in it first thing in the A.M., it hesitates when you first accelerate (for about 2-4 seconds.) Kind of like it's missing or flooding out. Outside temperature doesn't seem to make a difference. It runs like a champ after that first hesitation. Any help would be great!!!

Mine does the exact same thing (2000 Z71). BUT if I let it warm up before I take off it doesn't do it, but I never get up early enough to let the truck warm up

**N2TRUX** · 10-05-2006, 11:31 PM

Ok, my mistake here. I saw it was a 99 but didn't notice you said 5.7. I was thinking 5.3.

bluewhitepete is correct. If it stumbles at take off then it can be a sticking butterfly in the throttle body. They get a bit of carbon build that makes them bind just a bit when they first open. I had one that the shaft on the TB was causing the problem. I lubed the external linkage and it smoothed out.

See if that helps.

Jonboy · 10-06-2006, 08:38 AM

Also check your EGR valve. The hesitation off idle can also be traced to a sticking egr valve.

ain't_done_yet · 10-06-2006, 09:33 AM

Where is the EGR? That's one thing I haven't done, but have thought about. Is it easy to replace? How about $$

Thanks, Clay

Jonboy · 10-06-2006, 05:28 PM

It is on the intake, but not sure where.

09-27-2006, 09:06 PM	#1
ain't_done_yet and won't ever be Join Date: Jun 2000 Location: Arbala, TX Posts: 159	Hesitation in '99 Suburban 5.7: Need some help here...I have a 1999 Suburban w/113K on it. EVERYTHING has been serviced (that I can think of) but when you get in it first thing in the A.M., it hesitates when you first accelerate (for about 2-4 seconds.) Kind of like it's missing or flooding out. Outside temperature doesn't seem to make a difference. It runs like a champ after that first hesitation. Any help would be great!!! __________________ '82 SWB 1/2T Silverado (project) '96 SWB 1/2T Silverado, factory leather, Sony CD, Sirius Satellite 2006 Ram 3500 Megacab 4x4 SRW, AMSOIL/Injen CAI, AMSOIL By-Pass, Mag-Hytech cover, AMSOIL Lubriants throughout, and much more!! CHANGE YOUR MIND...NOT YOUR OIL

09-30-2006, 05:12 PM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,023	Re: Hesitation in '99 Suburban 5.7: When you say "EVERYTHING has been serviced " what does that include? Have you had the injectors cleaned? Rough idle and surging can be dirty or sticky injectors. If you haven't changed your fuel filter try that first. If that doesn't help consider a fuel system flush and injectors clean up. __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

09-30-2006, 09:22 PM	#3
ain't_done_yet and won't ever be Join Date: Jun 2000 Location: Arbala, TX Posts: 159	Re: Hesitation in '99 Suburban 5.7: Thank you for your response! I haven't actually had the injectors serviced, but I have been running AMSOIL fuel injector cleaner for about two years now (other brands B4 AMSOIL). The idle is actually smooth, just hesitates when you first accelerate. Also, I've replaced the fuel filter numerous times (WIX), and I have even replaced fuel pump (AC Delco)(that was fun). I just recently had the trans serviced 'cause the wife said it was shifting hard. I think this is something common on this truck. The trans guy said it was still throwing a code, so I may run it down to my buds at Oreilly's and have 'em check it out. __________________ '82 SWB 1/2T Silverado (project) '96 SWB 1/2T Silverado, factory leather, Sony CD, Sirius Satellite 2006 Ram 3500 Megacab 4x4 SRW, AMSOIL/Injen CAI, AMSOIL By-Pass, Mag-Hytech cover, AMSOIL Lubriants throughout, and much more!! CHANGE YOUR MIND...NOT YOUR OIL

10-05-2006, 08:51 AM	#4
bluewhitepete chevy72402 under a new name to get past a ban Join Date: Apr 2006 Location: SD Posts: 12	Re: Hesitation in '99 Suburban 5.7: try cleaning your throttle body. sometimes you get build up in there and it can cause hesitation, have you done a full tune up on it lately?

10-05-2006, 11:31 PM	#6
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,023	Re: Hesitation in '99 Suburban 5.7: Ok, my mistake here. I saw it was a 99 but didn't notice you said 5.7. I was thinking 5.3. bluewhitepete is correct. If it stumbles at take off then it can be a sticking butterfly in the throttle body. They get a bit of carbon build that makes them bind just a bit when they first open. I had one that the shaft on the TB was causing the problem. I lubed the external linkage and it smoothed out. See if that helps. __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

10-06-2006, 08:38 AM	#7
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Hesitation in '99 Suburban 5.7: Also check your EGR valve. The hesitation off idle can also be traced to a sticking egr valve.

10-06-2006, 09:33 AM	#8
ain't_done_yet and won't ever be Join Date: Jun 2000 Location: Arbala, TX Posts: 159	Re: Hesitation in '99 Suburban 5.7: Where is the EGR? That's one thing I haven't done, but have thought about. Is it easy to replace? How about $$ Thanks, Clay __________________ '82 SWB 1/2T Silverado (project) '96 SWB 1/2T Silverado, factory leather, Sony CD, Sirius Satellite 2006 Ram 3500 Megacab 4x4 SRW, AMSOIL/Injen CAI, AMSOIL By-Pass, Mag-Hytech cover, AMSOIL Lubriants throughout, and much more!! CHANGE YOUR MIND...NOT YOUR OIL

10-06-2006, 05:28 PM	#9
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Hesitation in '99 Suburban 5.7: It is on the intake, but not sure where.



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