1999 tahoe stalling

[paulyp697]

i have a 1999 tahoe that keeps stalling, after it stales it will restart. on short trips only stalls once. the other day drove 45 miles and kept stalling every 3 miles. now getting evap code po446 saying evap solinoide problem. could this be causing my problem

[jdl]

If you have the csfi fuel system, that system is noted for problems.

As far as the code you listed, several things might cause it, one, is a loose gas cap. Another is a vacuum leak. There are other causes as well.

[Skull Valley]

I'm currently having this same issue with my 2000 Tahoe (except without the code). I've replaced the fuel filter and fuel pump, but stalling still occurs while driving. I just got a call from the dealership repair center stating they can duplicate the problem, but can't diagnose it. I've seen people complain about this issue but haven't found any possible fixes. Not sure what to do.

Originally Posted by paulyp697

i have a 1999 tahoe that keeps stalling, after it stales it will restart. on short trips only stalls once. the other day drove 45 miles and kept stalling every 3 miles. now getting evap code po446 saying evap solinoide problem. could this be causing my problem

[Treblig70]

Test...Last time I tried to write-in it didn't work

[MT-2500]

Check for lose of fuel pressure or spark when it happens.
Is it setting any codes?

Next trip to the dealer.

Tip on going to the dealer
Ask that only a factory certified gasoline engine performance specialist work on your car.
Not all dealerships are concerned with how repairs are dispatched, and not all dealership techs bother to take advantage of the training offered by factory (the vast majority of which is paid training). If the dealer is uncooperative, ask for your money back and call around for a dealer that will accommodate you.

[Treblig70]

I drive a 99 Tahoe, 2WD, 350 Vortec, 120,000 miles. I had a problem with stalling, clattering under load [even a light load] and also had evap codes. I replaced the dist, timing chain, fuel pump [for better fuel pressure], fuel filter, plugs, wires, gas cap [GM], used GM fuel injection cleaner, and even tried premium gas. I spent well over $500 and got nowhere. I also asked for help on this site but really didn’t get any good answers. I finally gave up and took my Tahoe to the dealer. The dealer hooked-up their computer to the Tahoe, went for a test ride and blew the intake gasket while doing their road test. They said it would cost me $1800.00 to fix the water leak. I towed my Tahoe home and proceeded to tear down the upper half of the engine. I found corrosion on the intake [which probably caused the water leak]. I also found loads of soot, carbon and raw fuel in the intake [no fuel should be in the intake]. As it turns out….the original spiders [fuel injection system] get old and brittle. The spider eventually starts leaking fuel into the intake [where only air should pass]. The excess fuel flows to the back cylinders [the engine tilts back so the back cylinders run very rich] causing clattering/stalling under load AND evap codes [fuel fumes find their way back to the sensors in the evap system]. I had to figure all this out myself. I replaced the spider [$300] with the new improved version [much better and more reliable]. I replaced the intake [$500]. Took 2 hours to clean the intake. Long story short… Tahoe runs better than new!!! 6 months now…NO evap codes, no clattering, NO stalling under load and plenty of POWER!!!
I’m NOT saying that your spider is bad but what I am saying is that you shouldn’t spend hundreds of dollars on external items when the problem is internal. If you plan to replace your spider let me know and I can give you many tips on how to make the job easier, faster and better.

Gil in Tex

[maxwedge]

A static fuel pressure test would detect a loss of fuel that can and should be traced to the regualtor or spider assy, not magic and a well known issue. Disappointing that the dealer diddn't pick this up, usually a code other than the evap would be set with this condition as the engine would be running rich. Good job resolving this.

[Treblig70]

I did a static fuel pressure test as part of my troubleshooting and although it may give you an indication of the problem, it didn't show any discrepancies when I checked except slightly low fuel pressure [54 PSI]. There are conflicting fuel pressure specs [or actual real life experiences] some say 60-65 and some say at least 65, some at start-up, some after shut-down and some after 15 minutes of shutdown. Either way mine held pressure for 15-20 minutes after shutdown but my pressure was a little low during start-up and running. I replaced the fuel pump [$300], my pressure rose to 59-60 and the clattering/stalling continued. This occured during my 12 months of troubleshooting the clattering/stalling/evap code problem. It may be fuel pressure regulator [FPR] problems or fuel pump/filter problems or all three. The new spider comes with new FPR.
Everybody's input helps!!
Gil in Tex

[MT-2500]

Originally Posted by Treblig70

I did a static fuel pressure test as part of my troubleshooting and although it may give you an indication of the problem, it didn't show any discrepancies when I checked except slightly low fuel pressure [54 PSI]. There are conflicting fuel pressure specs [or actual real life experiences] some say 60-65 and some say at least 65, some at start-up, some after shut-down and some after 15 minutes of shutdown. Either way mine held pressure for 15-20 minutes after shutdown but my pressure was a little low during start-up and running. I replaced the fuel pump [$300], my pressure rose to 59-60 and the clattering/stalling continued. This occured during my 12 months of troubleshooting the clattering/stalling/evap code problem. It may be fuel pressure regulator [FPR] problems or fuel pump/filter problems or all three. The new spider comes with new FPR.
Everybody's input helps!!
Gil in Tex

I am a little mixed up here Treblig 70.
Are you Paulyp697 that started this post?
On you Tahoe is it not running right or still giving you trouble?
The fuel pressure test in this post is not a little low it is low.
There is no conflicting pressure specs.
The specs are 60/66 lbs of pressure.
In the upper post about asking for help here and not getting any good answers.
I remember that post and you did get some good answers.
You did not follow threw with the help that was giving.
Do you need more help now?
If so I would suggest start with a new post and some one will help.
This post has done mixed up my mind.
MT

[Treblig70]

Not sure where the confusion lies??? My Tahoe runs perfect now that I have the new spider. I spoke to many mechanics during the time I was troubleshooting the problem. Some suggested I replace the gas cap…I did. Some said GM injector cleaner…I did. Some said to check for leaks in the evap system…I did. Some said to do a “smoke test” where they inject smoke into the evap system to identify the leak….didn’t try that. One mechanic told me that if you overfill the tank it would flood fuel into the fuel neck overflow and put raw fuel in the evap plumbing, the excessive fuel vapors will give you an evap code [just like the leaking spider does]. I simply wanted the original poster to know that he could spend loads of money [like I did] replacing external parts when it might just be the spider. If I was him I would do a lot of troubleshooting before I spent too much. I only wish someone had told me about the evap system and its’ relationship to excessive fuel vapors in the evap system [well actually that one mechanic did tell me about overfilling the gas tank]. As for the original poster….he must have found his problem in which case we should know something sooner or later! As for me…you can find my post some months ago about my clattering under load. I did get some suggestions from this site but nothing about excessive fuel vapors and how a leaking spider can cause loss of power, valve clattering under load, evap codes and stalling. Now if only there was an easy way for the regular guy to attach a device to one of the air ports on the intake to measure excessive fuel vapors???????????????
Gil in Tex

[Treblig70]

MT-2500..Now I see where you might have gotten turned around by reading my post. MAXWEDGE suggested, "A static fuel pressure test would detect a loss of fuel that can and should be traced to the regualtor or spider assy".

I then submiited what had happened when I checked my system for presuure leak-down. What I was trying to tell PAULYP697 is that, just because your system doesn't leak-down too fast doesn't mean that your spider could still be bad. Mine held pressure for over 20 minutes but my spider was really nessed-up.
Gil in Tex

[MT-2500]

10-4
No problem.
I might have read the post wrong.
But any way you go remember proper testing to get to the problem.
And every one is usually a different deal.
Good luck
MT