Poorly running 89 2.9

[Mightyfordranger]

Hey guys i havent drive. This thing for awhile. And i know its got vac leaks i intend to fix the known ones. But when you get on it hard trying to get on highway it will break up and stumble superhard. But it fires right up and idles just wont pull under load.

If anyone knows where to look right off cool otherwise ill hunt the leaks and plug em as i go. Then report back what i find

 

[JMF661]

I would definitely fix up the vac leaks first. Maybe even redo all of the vac lines before continuing to diagnose. Especially if you are certain some exist.

 

[rusty ol ranger]

Fix the vacuum lines first, then pull codes.

 

[franklin2]

Sounds like a fuel delivery problem. Once you fix the obvious stuff like the vacuum leaks try it again. If its still messing up on a hard pull, go find yourself a pressure gauge, hose barb and clamp to clamp a long hose to the pressure gauge. 3/8 usually works, you might be able to use 5/16". What you are going to do is find the schrader valve on the fuel rail on the engine. This is the test port to test fuel pressure. Get a rag, and hold the rag around the test port (it's just like a tire valve) and poke the center to get rid of the pressure and soak up the fuel. Once you get rid of the pressure, find a tire valve tool that takes the guts out of a tire valve, take the guts out of the test port, and then slip your hose over the test port and use a hose clamp to clamp it tight. Run the hose/gauge up the back of the hood and tape it to the windshield.

Carefully close the hood and make sure the hose is not pinched. Start the engine, you should read about 38 psi give or take. Get out on the road and watch the pressure as you get down on the engine hard. Make sure the pressure stays up. It can actually go higher when you pull the engine hard, but you don't want it to go low.

 

[gaz]

Mightyfordranger:

I agree with franklin2, I believe you have a fuel management issue. Checking the fuel pressure is good move, may want to take a look at your O² sensor also.

 

[rusty ol ranger]

If it is sucking massive amounts of air into the intake thru bad vacuum hoses/gaskets/etc its going to make it appear as fuel delivery due to it being lean.

O2s can only compensate so much.

 

[fastpakr]

Agreed - fuel delivery is likely to be a symptom of the underlying issues you've named. You can't do a thing to troubleshoot until fixing the known issues.

 

[Mightyfordranger]

Fixed what i could find but it still stumbles. And thereis no cel either

 

[fastpakr]

Are there still vacuum leaks?

 

[Ranger850]

The title could have just said "2.9" lol

 

[Mightyfordranger]

I fixed all vac leaks i could find and replaced all but one vac hose cause i ran out of hose but it didnt look bad. Its got like a dead spot in the throttle i got it out on a end end road and hammered it. It loses power on the low end like below 2500 rpm then wakes up and takes off ut also started sticking the throttle at 3k rpm for some reason but if i shut it off it will "reset" and the idle will come back down. Thing is weird. I have a diesel and a 302 for it but no way do i have the time for any of that. Ill deal with burning oil etc but i at least gotta get the thing running decent. So it can be used ya know

 

[Mightyfordranger]

@PetroleumJunkie412 what do you think man

 

[Mightyfordranger]

Sounds like a fuel delivery problem. Once you fix the obvious stuff like the vacuum leaks try it again. If its still messing up on a hard pull, go find yourself a pressure gauge, hose barb and clamp to clamp a long hose to the pressure gauge. 3/8 usually works, you might be able to use 5/16". What you are going to do is find the schrader valve on the fuel rail on the engine. This is the test port to test fuel pressure. Get a rag, and hold the rag around the test port (it's just like a tire valve) and poke the center to get rid of the pressure and soak up the fuel. Once you get rid of the pressure, find a tire valve tool that takes the guts out of a tire valve, take the guts out of the test port, and then slip your hose over the test port and use a hose clamp to clamp it tight. Run the hose/gauge up the back of the hood and tape it to the windshield.

Carefully close the hood and make sure the hose is not pinched. Start the engine, you should read about 38 psi give or take. Get out on the road and watch the pressure as you get down on the engine hard. Make sure the pressure stays up. It can actually go higher when you pull the engine hard, but you don't want it to go low.

Ill have to give this a try. Not sure where to get a gauge rated for this but im sure summit racing has something they are bout 20 min away. I did replace the fuel pump and tank recently.

 

[fastpakr]

Any chain auto parts store (or even Harbor Freight) should have what you need.

Just to confirm - this is really a 2.9, not a V8 swap?

 

[Mightyfordranger]

Any chain auto parts store (or even Harbor Freight) should have what you need.

Just to confirm - this is really a 2.9, not a V8 swap?

Yes it is in fact a factory 2.9 v6 i was just mentioning i had other engines to swap but no time for it.
Ill take a look and see what the pressure is. Curious if it could be the regulator restricting flow untill vac gets high enough to force it open?
Also anyone know of a smoker kit to check for leaks? Would be super cool if i could rent one