97 gmc yukon misfires at speeds over 50

[lodownlv]

well first check to see if your fuel is spraying out of the injectors and not just streaming. the fuel presure reg should be located before the fuel lines to the injectors it should have a vacume line going to it. not sure where its located on tbi injection systems.

[Eggert]

Hi,
if I am not mistaken you do have two fuel injectors, just not one for each cylinder.
Take care, Eggert

[70GTORAG]

Check this out man!
http://www.automotiveforums.com/vbul...d.php?t=386078

[skisteeep]

I'll bet a lot, name a price, that it's the fuel filter. The good news is it's easy to replace. I did my first one today. Ask about problems. Same symptoms.

John

[Kevcules]

Originally Posted by Eggert

Hi,
if I am not mistaken you do have two fuel injectors, just not one for each cylinder.
Take care, Eggert

Eggert is right. You do have two injectors on your truck. The TBI unit is the shape of a carb, on top of your intake maifold. Take off your air breather lid and remove air filter and start truck. Hear that ticking noise , those are your injectors. Now look inside and you can see what should be a mist of fuel , move the accelerator linkage and rev the engine. Does the stream of fuel look good?? Lucas fuel injector is good stuff and wouldn't hurt to dump some in.
Kevin

[2000CAYukon]

The last year for TBI is 95. He has a 97 so he will have 8 injectors.

//2000CAYukon

[Kevcules]

Originally Posted by usscvr

No, I haven't.... ugh! I do not have individual injectors. My Yukon has a throttle body injector system, thus no fuel rails, no individual injectors, etc. I am still at a loss. Any suggestions????

"OK, if you read back in the post, you'll see that I have a throttle body fuel injection system, not individual injectors ~ so a 'bad injector' can be ruled out. "

I must have gotten this guy mixed up with the thread starter.Thanks for noticing 2000. Don't want to confuse anyone.

[Eggert]

Gentlemen, please help me out here.
If you do not have a carburator then you do have fuel injectors.
The 'older' TBI Throttle Body Injection has 2 injectors in the throttle body.
The 'newer' fuel injection has 8 injectors, one in each cylinder.
The only reference to a model year is by Suburbman asking if the problem with the 97 was fixed.
My 95 sub with the 4000 RPM limit had TBI.
The 96 and up engine has the 5000 RPM limit and is stronger.
Can each of you having the problem please specify model and year?
Take care, Eggert