85 Ranger Throttle Response Issue

[ISX_15]

Sounds like your classic dead spot on a cold engine? Does it improve after the engine comes up to temp? Is your electric choke working properly? I also put in a power valve that opens when the vacuum drops below 8.5hg. Sounds like a choke issue to me do you know what size main jets are in the carb?

doesn't improve once it gets up to temp, no clue if choke even works tbh i reside in AZ so cold starting is rare for me. No clue on the size jets, but i can tell you my whole motor is bone stock 2.8L V6. It could be a vacuum issue because this issue didn't start until last year, which is when i had it parked, its possible i could've forgot a line when i've worked on it.

 

[MikeG]

Too much air or not enough gas. If the pump is working (you should be able to look down the carb throat and see it squirt gas) then you have a vacuum leak, somewhere. Get a gage.

 

[19Walt93]

Try unplugging the EGR valve, the integral transducer can fail and instead of pulsating the valve will suck wide open and feed the intake charge a big mouthful of exhaust. Just because you see a squirt of fuel doesn't mean the accelerator pump is working properly, old diaphragms can get stiff and not flex properly and the linkage can bind. Also check the vacuum motor in the air cleaner for leaking. I'd want a full length exhaust system with a different muffler, it won't make it run much different but it will tone it down some.

 

[kimcrwbr1]

doesn't improve once it gets up to temp, no clue if choke even works tbh i reside in AZ so cold starting is rare for me. No clue on the size jets, but i can tell you my whole motor is bone stock 2.8L V6. It could be a vacuum issue because this issue didn't start until last year, which is when i had it parked, its possible i could've forgot a line when i've worked on it.

Did you find the vacuum diagram under the hood. In the tech library click engines then click ignition charging computer then click EEC-IV diagnostics. Find the diagnostic connector under the hood and make a jumper wire to reset the computer and erase the codes. All you need is a test light or VOM to pull the codes. It is easier to have someone write the numbers down as you count. How many miles are on the odometer?

 

[ISX_15]

Did you find the vacuum diagram under the hood. In the tech library click engines then click ignition charging computer then click EEC-IV diagnostics. Find the diagnostic connector under the hood and make a jumper wire to reset the computer and erase the codes. All you need is a test light or VOM to pull the codes. It is easier to have someone write the numbers down as you count. How many miles are on the odometer?

its gonna be abit before i get back to my project danger, sitting in my backyard right now. whenever my money is right i have to first replace the starter and get new set of tires
has about 70k on the odometer but who knows how many rollovers it had. coming from my uncle, he informed me it was used for work, he would transport 26FT straight trucks or whatever, have the ranger behind it towed so he can go home or whatever he had to do. ive check under the frame and what not, no rust, no buckling or sign of frame damage. basically its a 100% farm truck that need some TLC.
i am pretty soon like i said swapping it with the isuzu 4banger diesel maybe next year or so.
until then i just want my v6 to run smoothly and not stall out on me when im trying to take off from the light.
and about have guages and codes and what not, im 18, all i got is a common hand tool set haha.
but from the sounds of it more then likely its a vacuum problem.

if you wanna talk more in depth about it im more then happy to take inbox messages.

 

[ISX_15]

Try unplugging the EGR valve, the integral transducer can fail and instead of pulsating the valve will suck wide open and feed the intake charge a big mouthful of exhaust. Just because you see a squirt of fuel doesn't mean the accelerator pump is working properly, old diaphragms can get stiff and not flex properly and the linkage can bind. Also check the vacuum motor in the air cleaner for leaking. I'd want a full length exhaust system with a different muffler, it won't make it run much different but it will tone it down some.

should i just EGR delete??

 

[ISX_15]

also just a note i am not running a muffler, downpipe>cat>side exit
sounds good actually haha but im sure its affecting performance maybe.

 

[ISX_15]

quick update, cleaned carb, idles okay, revs okay, but like i said once its full throttle it stalls out, not sure if its too much fuel or not enough. i looked inside the carb and its getting fuel and when i open it up full throttle i can see fuel being sprayed in, so perhaps either too much fuel or a vacuum line? i have a two way PCV with one line going to the carb and the other one blocked off, i believe some emission things were removed

 

[ISX_15]

soon ill get some more photos posted in this thread, but what i also had found is a empty connector on the driver side on the wheel well, for the ECM?
unconnected plug next to the transmission, perhaps the shift light sensor or something i dont know
two more unconnected cables on the passenger side
also two blocked off vaccuum lines on the driver side engine, not sure what that part is or for.
thanks for feedback

 

[ISX_15]

ok folks so basically when i close the choke just enough, it eliminates that issue im having, so its more like, am i getting too much air? should i adjust anything? or should i look into replacing some mechanical parts or vacuum stuff?

 

[franklin2]

If you are getting too much air from somewhere, your idle speed will be too high, even with the throttle stop screw all the way off the throttle. If you can back the throttle stop screw all the way back and the engine slows and then stalls, then you are not getting too much air.

You could have a fuel issue. If the float level is too low in the carb, it will make the main venturi come in late and be a little lean. You can check the fuel level while the carb is on the engine if you are careful and do not drop any screws into the engine. You can run the engine and then take the carb top off after you turn the engine off and check the fuel level.

I can tell you if all these 2.8 setups are like mine ( I am assuming they are) they have a serious design flaw in the fuel system. I was having problems in hot weather with stalling and jerking, especially around town and pulling a mountain road. I found on the driver's side the fuel line comes out to go around the frame rail, and is way too close to the exhaust system there. I took a piece of old heater hose, slit it down the side, and wire tied it around the fuel line to insulate it from the exhaust in that area, and the problem is much improved.

 

[ISX_15]

If you are getting too much air from somewhere, your idle speed will be too high, even with the throttle stop screw all the way off the throttle. If you can back the throttle stop screw all the way back and the engine slows and then stalls, then you are not getting too much air.

You could have a fuel issue. If the float level is too low in the carb, it will make the main venturi come in late and be a little lean. You can check the fuel level while the carb is on the engine if you are careful and do not drop any screws into the engine. You can run the engine and then take the carb top off after you turn the engine off and check the fuel level.

I can tell you if all these 2.8 setups are like mine ( I am assuming they are) they have a serious design flaw in the fuel system. I was having problems in hot weather with stalling and jerking, especially around town and pulling a mountain road. I found on the driver's side the fuel line comes out to go around the frame rail, and is way too close to the exhaust system there. I took a piece of old heater hose, slit it down the side, and wire tied it around the fuel line to insulate it from the exhaust in that area, and the problem is much improved.

yeah it does high idle and i did try putting the stop screw enough to the point where it wasnt even touching the throttle cable.


tbh all this fuckery this ranger is giving me, considering its hard to even get aftermarket parts for it, i should just opt in for a fullsize pickup for a project

 

[franklin2]

You will end up exchanging one set of problems for another, been there, done that.

Sounds like you do have a large air leak. What you can do is get some brake cleaner or carb cleaner, something the engine will run on. Make sure it's flammable and the engine likes it. Then with it idling, spray the cleaner around the base of the carb and in different areas and see where it affects the idle the most. When the air leak starts sucking in the cleaner, the engine should rev up noticeably.

 

[ISX_15]

You will end up exchanging one set of problems for another, been there, done that.

Sounds like you do have a large air leak. What you can do is get some brake cleaner or carb cleaner, something the engine will run on. Make sure it's flammable and the engine likes it. Then with it idling, spray the cleaner around the base of the carb and in different areas and see where it affects the idle the most. When the air leak starts sucking in the cleaner, the engine should rev up noticeably.

you're right ill give that a try, when i was using the carb cleaning outside of the throttle body i did notice the idle fluctuating, perhaps i could have bad seals, i should probably get a gasket kit or something

 

[ISX_15]

you're right ill give that a try, when i was using the carb cleaning outside of the throttle body i did notice the idle fluctuating, perhaps i could have bad seals, i should probably get a gasket kit or something

it is arizona aswell so starting off by replacing gaskets should be a good start