Patchestoyota

hello fellow yota owners im new to this site have question concerning 94 with 22re just dropped 7 bigs ones chasing a ghost on mas airflow throttle body rebuilt truck will drop in power while driving and act as if its not getting any air heelllpp please any suggestions???? thank you

wyoming9

iTrader: (1)

Well if you have a Mass Air Flow Sensor on a 22re that might be part of your problem.

Losing air Filter blocked from never having been changed.

Rodent nest in the intake.

Those two are about the only two things that would cause a loss of air.

You have ruled out any fuel related problems??

Thommo Thompson

ok symptoms of not getting any air are the car rapidly decelerating like the brakes are on, or engine unable to eun. so choose words carefully, ppl will start looking foe air related iaauea.
im going to assume u simply mean the engine bogs down?
and i think what ur saying is uve been "chasing a ghost" by throwing money at things before having any clue at all as to what ur symptoms might be? is that a good analysis of the situation?
Effectivwly, alll uve given us to work with is..
"cars not running good, someone help"
we need much much more information, or else ur going to receive a sea of useless replies.

Patchestoyota

yes to both what i meant to say is the vfm/vam not mas air flow.@thommo the problem is when your driving and it bogs down , as if no air supposedly the shop could fix it but they couldnt, the vfm was sticking preventing it to start ,replaced, and it starts but when it gets warm it starts bogging i dont know could it be the egr??? i checked it with a vacuum gauge, i dont know? any suggestions thanks

ksti

Not mentioned, but possible TPS out of spec.

Patchestoyota

ksti that is one thing i didnt check neither did the mechanic its a possibly thanks

akwheeler

you could also check for a plugged catalytic converter, pull an O2 sensor in front of the cat or break a flange loose before the cat, you'll get check engine lights and it will be loud, but if it doesn't load up and bog down like before (drop in power while driving) you know it's the cat. Air has to get in, but exhaust also has to get out.

Thommo Thompson

ok nothing u are typing is mak8ng any sense to me.
what the hell is vfm/vam, or are u just making up acronyms?
u havent explained why u think its starved of air.
bogging down means lacking power.
Gasoline engine needs more than just air to operate.
Air, fuel, compression, spark, timing and exhaust.
So lacking power, can be any one of those.
im just not underatanding ur poats. 5hey are very poorly written. slow down and take the time to explain the problem and please use fullstops, question marks, and sentence and paragraphs.

Thommo Thompson

and if u really mean the air flow meter, what u said makes no sense. it doesnt stick. sensors dont stick.
sorry i cant believe people are suggesting specific parts to check, we have no idea of what the problem is because nothing uve said makes any sense yet. for that reason, the suggestions above are null and void and are simply just plucking at straws.

Patchestoyota

@thommo the door in the air flow meter was not opening,where the air filter goes, that prevented it from starting, when you would open it manually it would start, now that it starts when your driving at speed the truck loses power and bogs down,i have fuel spark and air. ive repaced injectors ,fuel pump as well as the air flow meter(mass air flow) if thats the correct terminology. my question is whatelse would cause this problem of loss of power if plugs wires and timing are all good? thank you.

Thommo Thompson

ok so your not necessarily getting choked of air. lets make that clear
Was the VAFM replaced with a brand new one?
If so, then it must be functioning properly.
Bogging down under power is a result of net enough fuel or not enough spark. considering what you have changed.
Not enough fuel can be because of a sticking VAFM if u boguh t a used one, (undereading the air, causing lean mixture), or fuel pressure regulator, or fuel filter.
Not enough spark can be leaking HT leads, plug gaps worn out of spec, dizzy cap cracked, coil failing, or insufficient current at coil positive.

Patchestoyota

@thommo ,yes the vafm was replaced with a new one ,plugs and wires as well as cap was replaced also fuel filter was the first thing i replaced.the coil looks good and i assume they either go out or work.would it just go out intermittent? forgot to mention i replaced fuel pump and injectors...
now the fuel pressure regulator???? not the pump correct? lol that would suck if i have to drop the tank again. i appreciate your feedback thommo.

Thommo Thompson

coils only ever slowly die. they dont just go BLAERHH.
Coil symptoms are often more pronounced under high load low rpm conditions where u get a missfire or lack of power. Coils can be tested but a good test cannot rule out a heat related failure or a load related failure. As the engine asks for more power, the spark actually automatically pulls more power from the coil. If the amount available is diminished, u will get high load missfires.
a fuel pressure regulator failing would be most prominent at high rpm high load. But dont stress, the regulator is on the engine not in the tank haha.
What exact stage of engine operation are u getting the bog down.

Thommo Thompson

to explain the fuel preasure regulator and how it can be the issue. study this image. ( see link below)
under high engine load, manifold vacuum suction is low because the throttle plate is opened and the pistons are still catching up to the speed that the open throttle is trying to achieve.
In this scenario, under load, the lack of vacuum applied to the diaphragm on the other side of the spring is supposed to let the spring overcome the low vacuum and stop fuel escaping through the return. if the spring is snapped, old and worn, or stuck, the low vacuum will still be strong enough to pull the diaphragm and open the fuel return , limiting the fuel preasure to somewhere near where it would supposed to be closer to idle or coasting.
another failure is when the vacuum is diminished or the diaphragm is ruptured, thus causes the opposite, the spring always overcomes the vacuum and fuel pressure is always too high. but ur problem is more likely the lean failure.

https://www.google.com.ph/search?cli...RX3fygeibyCyM:

Thommo Thompson

perhaps a really dodgy way to test if its the regulator is to disconnext the vacuum line to the regulator and plug it so that the hose doesnt become a large vacuum leak.
Then go for a hard drive. I am not responsible for any fuel rail explosions this may cause.

thefishguy77

iTrader: (1)

When you replaced the injectors it is also possible that you may have damaged a wire inside the insulation. Ask me how I know. Mine was totally intermittent. Would work great for 2-3 days. Then keep trying to die. Sometime it wouldn’t run more than 20-30 seconds. Sometime it would only have problems when it was hot or cold. I finally gave up and found a guy, at the recommendation by my buddy that owns a shop, that eats sleeps and breaths electrical, after my friend that runs the shop worked on it for 2 days and couldn’t find anything “repeatable”. The electrical guy started testing resistance on all the minor components and sure enough found 2 separate wires to injectors that were damaged. He fixed those and she runs just fine.

It can be hard and frustrating when troubleshooting a problem like this. The wires are now over 20 years old and wire gets brittle with age. I am sure there are many other possibilities but I hope you get it figured out soon.

Edit: What brand parts are you putting on? These older trucks seem to really like Aisin, Denso, NGK, and several others. But can get really finicky with Bosch and a few others as well.

Patchestoyota

thanks ill trip around on that fuel pressure regulator cause it happens under load,@ fishguy, i try to use oem parts on major components, i appreciate the input i bet its something simple and something i over looked. thats why i prefer working on my 64 c10 much easier lol. appreciate the help

thefishguy77

iTrader: (1)

Rockauto is a good website for affordable OEM brand parts.