unusual jumping

[jeremymik84]

my 01 tahoe 5.3 is doing this crazy jumping thing when im accelerating..its kind of like its starving of fuel for a split second long enuf to nosedive somewhat...ive read codes and it said MAFS so i changed that...now it still says that and says purge or vent solenoid..any ideas??

 

[TnTahoe]

I would suggest a fuel filter change first, does your gauges do anything while its surging

 

[jeremymik84]

the rpm's drop a tad bit but its not long enough to drop em alot..it seems to do it alot more when my speakers are booming :-D

 

[NathanJax]

see... this is a very technical question and wouldn't help doing it in chat...


While having the intake off, did you look at the throttle body? was it dirty? did you clean it? Does the butterfly valve (or whatever) seem to open and close smoothly?

 

[jeremymik84]

haha, i did check it...it didnt seem to be very dirty at all suprisingly...,maybe i just couldnt see far enuf lol...cant really say about the butterfly valve i dunno how easily its sposed to move

 

[TnTahoe]

Check the wires going to your fuel injectors, mine did similar and found out that some squirrels had eaten through some of the wires

 

[NathanJax]

haha, i did check it...it didnt seem to be very dirty at all suprisingly...,maybe i just couldnt see far enuf lol...cant really say about the butterfly valve i dunno how easily its sposed to move

should move easy and fluently. if it's catching, that's your problem.

 

[jeremymik84]

it doesnt catch, however when it closes by itself it kinda flaps back n forth like a saloon door just not as dramatic

 

[nimrod.sixty9]

I think its best if we get more details. Im really curious about the actual code number and details your recieved from the OBD scanner.

Also, does it do it when hot, cold, both?
Accel only? Any other symptoms? I
s it missing, or completely dieing out?
Does it recover or fail entirely?

Get us some details.

 

[jeremymik84]

it does it anytime...mostly accel rarely while cruising or on cruise control...its not dying just split second stutter..and then back to normal...but itll do it 3,4 times back to back then be good then randomly do it again lol..