89 351 intake sucks in air rapidly runs rought and then dies plz help

[bronco72]

i have a 89 fullsize ford bronco some days it runs good and others it runs not to hot. i just replaced the idle control and the tps, plugs, and cap rotor. It help but it didnt fix the problem. im getting fuel the only thing i could think it is the air going in the intake. when its running good the air is not sucking loud and smooth but when its running like crap it sucking loud and is rapidly like its turn a vacume is getting turned on and off really fast the the rpm goes up and down and if u give it pedle (gas) it back fires and die so if any one could help me that would be great i have used crab cleaner around the intake and i didnt have any smoothing out or high idles either. timing is on plz help thanks

[rhandwor]

If you have a cracked valve spring they will back fire. Try doing a compression test. Ohm all plug wires you should have appx.1/2 scale. A break in the wire will cause a back fire. Pull the vacuum line to the fuel pressure regulator if you have gas in it replace it. Spray around any injector base and any pcv hose.
A bad EGR will cause stalling.
Note if you have a bad spring reply and I will tell you how to change it without pulling the head.

[bronco72]

Originally Posted by rhandwor

If you have a cracked valve spring they will back fire. Try doing a compression test. Ohm all plug wires you should have appx.1/2 scale. A break in the wire will cause a back fire. Pull the vacuum line to the fuel pressure regulator if you have gas in it replace it. Spray around any injector base and any pcv hose.
A bad EGR will cause stalling.
Note if you have a bad spring reply and I will tell you how to change it without pulling the head.

thanks but it only thing thats making it back fires when i give it gas but the thing thats making it idle not right is the air going in to the intake. the intake is acting like its getting to much air or not enough i dont have egr any more either i got rid of it when i got header. thanks would springs still be it if it runs good for 5days then acts up and runs bad lol

[rhandwor]

I've had worn valve guides and the engine runs fine and then the push rod moves and the lifter doesn't work correctly. I removed the valve cover looked and used my hand and wiggled each one until I found it.
I always found vacuum leaks by spraying the intake and hoses until the engine smoothed out.
A stretched timing chain I rotated the engine by hand to appx. 60 degrees past TDC then rotated it back to zero. I then pulled the distributor cap marked the rotor tip and base with whiteout. I had somebody watch the rotor
and turned the engine by hand stop as soon as the rotor starts to move.
Anything over 20 degrees can cause problems.
Disconnect the sprout and set the timing. Then plug in the sprout. If you had to move it much you normally have other problems unless you worked on it and didn't reset it.
On older engines with mileage you can easily have mechanical problems.
Vacuum leaks will make them run rough but normally cause backfire if other things are correct.

[bronco72]

Originally Posted by rhandwor

I've had worn valve guides and the engine runs fine and then the push rod moves and the lifter doesn't work correctly. I removed the valve cover looked and used my hand and wiggled each one until I found it.
I always found vacuum leaks by spraying the intake and hoses until the engine smoothed out.
A stretched timing chain I rotated the engine by hand to appx. 60 degrees past TDC then rotated it back to zero. I then pulled the distributor cap marked the rotor tip and base with whiteout. I had somebody watch the rotor
and turned the engine by hand stop as soon as the rotor starts to move.
Anything over 20 degrees can cause problems.
Disconnect the sprout and set the timing. Then plug in the sprout. If you had to move it much you normally have other problems unless you worked on it and didn't reset it.
On older engines with mileage you can easily have mechanical problems.
Vacuum leaks will make them run rough but normally cause backfire if other things are correct.

i'm sorry if i'm wasting ur time would worn valve make the air going in the intake not right. if i do have to replace the valves and springs. i have to pull ever thing on top don't i. A stretched timing chain would make timing slip to thanks ill try that tonight

[rhandwor]

Start at the air filter and follow it back to the throttle. Look for any busted air hoses and make sure the air filter is clean. Look over the entire intake for cracks. Clean the throttle and clean the air flow meter. If after spraying it with carb cleaner any leaks found will smooth the engine.
The air goes into the intake valve fuel is sprayed into the cylinder and it is compressed and the spark plug ignites the mixture. Worn valve guides you have to take to a machine shop and get done. Valve springs you can replace without pulling the head. A compression tells you what cylinder to check then pull the valve cover and look. Pulling the valve covers will tell you a lot. You can't fix it until you find the problem.
Without a gasket leak or crack where is the air coming from I basically am not certain what is going on from your description. Basically you have to do some checks until you find out what is happening.

[bronco72]

the only thing i could think of is its getting to much air. when it starts to act up it a loud sucking from the intake if u give it gas it backfires or just die

[bronco72]

Originally Posted by rhandwor

Start at the air filter and follow it back to the throttle. Look for any busted air hoses and make sure the air filter is clean. Look over the entire intake for cracks. Clean the throttle and clean the air flow meter. If after spraying it with carb cleaner any leaks found will smooth the engine.
The air goes into the intake valve fuel is sprayed into the cylinder and it is compressed and the spark plug ignites the mixture. Worn valve guides you have to take to a machine shop and get done. Valve springs you can replace without pulling the head. A compression tells you what cylinder to check then pull the valve cover and look. Pulling the valve covers will tell you a lot. You can't fix it until you find the problem.
Without a gasket leak or crack where is the air coming from I basically am not certain what is going on from your description. Basically you have to do some checks until you find out what is happening.

the only thing i could think it is is its getting to much air when the motor starts to act up theres a loud suck form the intake. if u give it gas it back fires or dies most of the time it dies.

[rhandwor]

Look closely for intake leaks I've found hose cracks which cause problems.

[bronco72]

Originally Posted by rhandwor

Look closely for intake leaks I've found hose cracks which cause problems.

ok im going to try to take it to guy and see if he can scan it ok thanks

[bronco72]

Originally Posted by rhandwor

Look closely for intake leaks I've found hose cracks which cause problems.

i didnt find any vacuum leaks on any of the hose. theres a vacuum sneser on the side of the in take if u unplug that it dise nothing would or should i replace that senser i dont know what else it would be on this.

[rhandwor]

Do you have any computer codes?

[bronco72]

Originally Posted by rhandwor

Do you have any computer codes?

it didnt make it that far to get scaned so i think im going to try to get it towed there tomorrow or maybe it will run better tomorrow. I just dont get it it runs great for 5 days then is runs like crap. thanks for all ur help to

[rhandwor]

Look at 89 Bronco fires but won't run. The link has pictures.

[bronco72]

Originally Posted by rhandwor

Look at 89 Bronco fires but won't run. The link has pictures.

but im getting fuel and sprak lolim not getting the right air going in so its not mixing right nad making it run like poop :?