Backfire issue...help please

[Trey Figgity]

I have a 1989 v1500 suburban....350 TBI...set the timing so I know that's not it....went to googling and I've heard every reason under the sun...

It's running rich (because I can smell sunburnt gas). It starts fine....turn key, no gas and fires right up....

It does seems to be idling high, says for this motor there is no idle adjustment ‍(not sure if true)

But biggest issue is when I'm in gear and have foot on brake, if I hit the gas at all it backfires... never in neutral and never in park.....

I'm hella lost, any advise would be great...thank you in advance


Trey

 

[AuroraGirl]

You set the timing but not the idle…. Did you actually set the timing by removing the mandatory plug that tbi timing procedure calls for?

Because setting the idle is usually found with that information often. Just curious. You have an idle set procedure to adjust the minimum air screw to just barely idling without the computer intervention and this process requires jumping two pins of the aldl. You can Google it for further but just making sure