2.5L ('98-'01) garbage 2.5l

[Mightyfordranger]

So recently I picked up a 99 ext cab 5spd 2wd 2.5 truck. With a bad rear end. For 500$. Which wasn't an issue cause I had a good rear end from my old 98 ranger same truck but wrecked in the front.

I swapped the axles and fixed some exhaust probs it was broke right at the collector. Made a "quick fix" and got the truck out for its maiden voyage.

And man is that thing is scary at 65+ shakin like a dog $h#tin razor blades. Then all of the sudden it starts breaking up and running rough. Played hell getting it back home.

Its bogging under a load and I have to tach it up real high to get it to move. And if I hold it to the floor long enough it will eventually come to life and take off like normal... Anyone got any ideas where to look first??

I'm gonna look for anything obvious first loose connections etc. But beyond that where do you guys think I should look first.

It will fall on its face at first then wake up and take off then when you shift it will drop off again and cont the same way.

 

[RonD]

Change fuel filter first, maybe drain some gas and check it for water, or drain the tank all the way and put in fresh gasoline
Clean MAF sensor

Check fuel pressure, if possible, 1998 and up Rangers use 55psi, 1997 and older 35psi

Long shot is that the exhaust is worse than you think, Cats or muffler is rusted out and broken up inside so blocking flow, and it can come and go as pieces shift around, which kind of fits your description

 

[scotts90ranger]

severe metered air leak or like Ron said clean the MAF, but I think you're on the right track... if possible pull trouble codes, they could help. If it runs ok cold but gets bad hot the O2 sensor is probably roasted...

 

[Mightyfordranger]

Thanks for the reply guys. Yeah my "quick fix" isn't quit the greatest lol I hammered a piece of 2 in pipe into a flange for the collector and drilled out the manifold bolts. Seemed like the louder the truck got the worse it ran. I'll fix that better for sure and post up some picks for your viewing pleasure. Lol perhaps tommorow when I get time in the Am

Side note: I put it together with all the spare parts from all my other rangers. So its got the newest style shift stick. The bigger mirrors. A center console thing with a cup holder. ( my most favorite addition yet) I cleaned like a 2 ft pile of trash out of and found a garmin thingy!! Lol I'll make a whole post bout it later with pictures.

 

[PetroleumJunkie412]

Sounds like your manifold leak is driving your O2 nuts.

Happened to mine with the egr blockoff stud. Stud was leaking and i found a bunch of other holes in the manifolds once I had them off. Reason it ran so well after I put headers on is the O2 finally worked.

 

[scotts90ranger]

If you have a big gaping hole within a few inches of an oxygen sensor that could definitely be your problem... good rule of thumb is 18" of exhaust behind an oxygen sensor... a small hole you can't hear after a collector (and near the O2 sensor) isn't a huge problem, but if you can hear it it's also leaking air in and thinking it's running lean...

 

[tomw]

Plug wires can cause intermittent problems as described. Run as if only 2 cylinders functioning, then wake up and run fine... Check the ohms end-to-end. If you get OL, get new wires. There's a rule of thumb as in 1k ohms per foot, but I'm not sure of the '1'. Open will make the spark jump multiple gaps, and it will find shortcuts way prior to the spark plug itself...
tom

 

[Mightyfordranger]

I didn't get up early enough to mess with the truck was up late. (Dam second shift)

 

[Mightyfordranger]

ok so I got the truck driving straight and not trying to kill me anymore. it seemed to clear itself up once I got that exhaust fixed better. will actually get to a hold 70mph.

But it doesn't have heat has me scratching my head. Seems like the blend door is cooperating and the blower motor is working only on high though. (non issue yet)

Now that little 4 way valve thing, its getting 15 in merc all the time when I had my gauge on it. So I guess my question is how does that valve play into the heat system? the truck has A/C but it wont kick the pump on, but it will do everything else in the cab like it should when you turn the switch.

From what I have read the little valve under the hood gets vac, only when you turn it to heat on the selector.

I did put like 20 in merc of vac on that valve and it still had no heat, the heater hoses seem warm not super hot but warm I could still hold them.
just wondering if that 4 way valve is trashed.

 

[RonD]

The by-pass valve should only have vacuum when MAX AC is selected in dash controls, when it has vacuum it by-passes flow thru heater core for max cooling in the cab

So unplug that grey vacuum hose and plug it with a screw/bolt for now
Should be a GREY vacuum line that comes out of the firewall, if not someone screwed up and hooked up the wrong vacuum line to it

Anyway that should get your heat back in the cab
No vacuum at by-pass valve = heat in the cab, if valve is working OK

Other than that only the Blend Door controls temp in the cab by directing air flow thru or around heater core in varying degrees

 

[Mightyfordranger]

Ok quick update. I checked the vac line again it gets vac with the selector is "off".
I unplugged that vac line which is gray. And still no heat.

Pulled live time data with my ob2 thing coolant temp was 190 max and steady.
The gauge worked as well.

Once i unplugged that vac line i still got no heat. But i can say the actuator is working i can hear it change tone with the blower. And feel it turn super slow if i put my finger on it.

Seems to me that that valve is done?
My question is can i bypass it safely with copper pipe to see if i can get results? Also is there a specific cleaner used to clean heater cores? Would regular drain-o work?

Also i found post you made awhile ago Ron. That how i got this far ha ha!!

 

[PetroleumJunkie412]

Also i found post you made awhile ago Ron. That how i got this far ha ha!!

RonD is Canadian God.

His old posts are the Canadian bible.

 

[RonD]

Yes, if heater hoses are not heating up with vacuum unplugged then you can by-pass the by-pass, lol, with just straight fittings, there is no "order", as long as one engine hose is patched to one heater core hose you will get flow thru the core, assuming its not plugged up.

The only reason the by-pass is there is for MAX AC, as said, so really up to you if you want to even replace the by-pass.

AC still works in MAX AC setting, plug that grey hose, MAX AC's main benefit is that it closes the OUTSIDE AIR VENT, so instead of trying to cool down HOT outside air, the fan sucks in already cooled air from inside the cab to cool it even more

 

[Dirtman]

I'm not helping you because you called the 2.5 garbage...

 

[Mightyfordranger]

I'm not helping you because you called the 2.5 garbage...

The whole truck was garbage when I got it. I mean the guy literally used it as a trash can!

And I affectionately called it garbage, its my garbage 2.5!!

I pull some much gross stuff out of it. Like old socks and like 5$ in really gross sticky change.

And oddly a large number of nails??

Ooo and a garmin (also gross)

But Ron what about getting a specific core cleaner?? Or just draino or CLR or something??