1996 Bronco 5.8L surging at light throttle

[Tbeck]

Just like the title. Very noticeable at a light touch on throttle. Idles fine, heavy throttle also fine. Rig has 178k, no leaks etc. What say you, Broncozone?
TBeck

 

[Tiha]

Check engine light on? Any codes?

Light throttle, is the throttle body worn out? Vacuum leak?

 

[Tbeck]

Doesn’t appear to have a vac leak (ether test…). I didn’t think of throttle body. Thx!

 

[L\Bronco]

Doesn’t appear to have a vac leak (ether test…). I didn’t think of throttle body. Thx!

Could be a dead spot in the TPS, just off of closed throttle, Ive seen a sticky PCV valve cause a tip in surge (very rare though), does vehicle speed affect it at all, and as Tiha asked, are there any codes?

 

[Tbeck]

Never thought to hook up code reader as no lights. Seems more a throttle position deal (lightly tough foot feed).

 

[Tiha]

At this point is really is kind of a shot in the dark.

Does it happen at a particular MPH, or does it happen sitting in park?

Or does it clear up at crusing speed? But it runs fine at idle and full throttle?

Does it happen above or below 200o rpms, or both?

Could it be something like the AC compressor kicking on and off?

So yes there is a lot of things to check. Back in the early 90's the GM 3.1 wouild start surging very gently under light throttle at any speed. owners would swear it was the transmission or at least a torque converter issue. Turns out that was a bad injector.

TPS is a great thing to check, probably use a DVOM to test it. Maybe check fuel pressure as well?

Just trying to eliminate as much as we can.

 

[miesk5]

Yo Tbeck,
As advised by Tiha & L\Bronco, TPS TEST @ https://www.fullsizebronco.com/thre...or-testing-replacement-and-adjustment.203080/

Also,

 

[johnnyreb]

Yo Tbeck,
As advised by Tiha & L\Bronco, TPS TEST @ https://www.fullsizebronco.com/thre...or-testing-replacement-and-adjustment.203080/

Also,

How about that catalic convertor? It could be stopped up and the oxygen sensor could be sending the wrong signals---especially if it has alot of miles on it.---Its something I have noticed --seems like no one pays attention too.

 

[L\Bronco]

Doesn’t appear to have a vac leak (ether test…). I didn’t think of throttle body. Thx!

Hey Tbeck:
did you have any success with your surge?
Cheers

 

[Tbeck]

Hey Tbeck:
did you have any success with your surge?
Cheers

Calves started dropping so been distracted! I will post when I puzzle it out ( I hate unresolved threads!!)

 

[L\Bronco]

Calves started dropping so been distracted! I will post when I puzzle it out ( I hate unresolved threads!!)

Totally get that, (I grew up on a dairy farm)
Take your time, just want to make sure you got the help you need

 

[johnnyreb]

Totally get that, (I grew up on a dairy farm)
Take your time, just want to make sure you got the help you need

A friend of mine.Went to check on a cow that was gonna have a calf and almost got killed. He said he tried to out run her and she hit him in the back and throwed him in the air. It boke his leg Ondecided to do something to you. Ye day we were out in the field where some of the cows were. Hear they came and I started to the truck. He laughed at me. I told him as big as a cow is and if it decided to harm you--it could. Its why I use some caution. Another friend of ours was telling us about a cow he had. He said he never seen any bulls as mean as she was and one day he got fed up with her and took her to the stock yard.

 

[Tbeck]

Gotta watch ‘em close. I have one crabby momma out there right now, calved Sunday morning and was still giving me the business yesterday. When I go to feed tonight I will be carrying my pick-axe handle in case she still isn’t seeing this game my way. Cows aren’t so bad; but, Grandpa always told us to never trust the bulls. And I don’t!

 

[johnnyreb]

Gotta watch ‘em close. I have one crabby momma out there right now, calved Sunday morning and was still giving me the business yesterday. When I go to feed tonight I will be carrying my pick-axe handle in case she still isn’t seeing this game my way. Cows aren’t so bad; but, Grandpa always told us to never trust the bulls. And I don’t!

Mom and I were coming out this country road. They had this big bull in a big round metal fence and some coms in the pasture. Then they released this young bull in the field. This big bull syarted going nuts. He has pushing the fence around like nothing. Mom said how stupid can they be, Anyone who has been around cows and bulls knows.. You don,t do that, That big bull will **** the small one. We never stuck around. That big bull was blowing snot every where, He was real mad. How,s the weather in Montana now?

 

[johnnyreb]

Mom and I were coming out this country road. They had this big bull in a big round metal fence and some coms in the pasture. Then they released this young bull in the field. This big bull syarted going nuts. He has pushing the fence around like nothing. Mom said how stupid can they be, Anyone who has been around cows and bulls knows.. You don,t do that, That big bull will **** the small one. We never stuck around. That big bull was blowing snot every where, He was real mad. How,s the weather in Montana now?

be careful and have a safe day

 

[L\Bronco]

Gotta watch ‘em close. I have one crabby momma out there right now, calved Sunday morning and was still giving me the business yesterday. When I go to feed tonight I will be carrying my pick-axe handle in case she still isn’t seeing this game my way. Cows aren’t so bad; but, Grandpa always told us to never trust the bulls. And I don’t!

Whats the breed?

 

[Tbeck]

Mom and I were coming out this country road. They had this big bull in a big round metal fence and some coms in the pasture. Then they released this young bull in the field. This big bull syarted going nuts. He has pushing the fence around like nothing. Mom said how stupid can they be, Anyone who has been around cows and bulls knows.. You don,t do that, That big bull will **** the small one. We never stuck around. That big bull was blowing snot every where, He was real mad. How,s the weather in Montana now?

Terribly dry in the east (I’m up in the NE corner), although some spots are getting some moisture. As far as the bulls go, that’s the worst part of a cow/calf operation. They gotta work for 2 months, eat for 12, and fight & tear things it for 10!

 

[johnnyreb]

Terribly dry in the east (I’m up in the NE corner), although some spots are getting some moisture. As far as the bulls go, that’s the worst part of a cow/calf operation. They gotta work for 2 months, eat for 12, and fight & tear things it for 10!

I was telling a friend one time. About starting a junk yard. He said you,d have to get some dogs.So people wouldn,t steal off of you. I told him I wouldn,t have dog,s. I,d get a bull and he said no one would come around then. They used to rip me off hear. Until I spotted a big rattler out back one day and told some friends about it. They asked if I killed it and told them I started to,but got to thinking. I,d let it guard my stuff--now no one bothers it. . That suckers about 5 feet long and as big around as my arm.