1984 cargo acts like a bad accelerator pump would if there was one.

[zosteria]

if there was a carb id know exactly what to do but there's not. I replaced the TPS, the old one was not giving continuity to the higher range points. I have had the throttle body off 3 times now and I am at the end of my rope.15 lbs of vacuum on the manifold holding steady, I can't find any vacuum leak, the MAF is clean and moves freely. if I rev up high before I load it up it will go. I can get the van to 60mph. I'm all out of ideas. when I step on the gas fast it dies out.

[llamavan]

Have you checked for codes (https://www.toyotavantech.com/forum/content.php?196-Engine-Service-Connector)?

O2 sensor status?

Gwen

[timsrv]

Sounds like a cracked intake tube. While it's idling, squeeze the tube that goes from the air box to the throttle body. If it stumbles and/or dies when you squeeze, then that's your problem. For more info, check the 2nd post of THIS THREAD (https://www.toyotavantech.com/forum/showthread.php?849-erratic-rough-idle-p-s-leak-amp-noise-sensors)

[zosteria]

Sounds like a cracked intake tube. While it's idling, squeeze the tube that goes from the air box to the throttle body. If it stumbles and/or dies when you squeeze, then that's your problem. For more info, check the 2nd post of THIS THREAD (https://www.toyotavantech.com/forum/showthread.php?849-erratic-rough-idle-p-s-leak-amp-noise-sensors)
I had a somewhat questionable hose, but I replaced it and it didn’t change anything. I haven’t tried the oxygen sensor. Does anyone know where that is? I’m also wondering about the temperature sensor that’s on the side of the filler neck is that something that can be tested? The van idles perfectly and doesn’t miss it just bogs like someone cut a hole in it if I step on the gas

[timsrv]

Do you have any codes?

[llamavan]

I had a somewhat questionable hose, but I replaced it and it didn’t change anything. I haven’t tried the oxygen sensor. Does anyone know where that is?

O2 sensor mounts into the exhaust pipe and is before the catalytic converter (1st gen vans only have the one, and it rarely throws a code when it goes bad in my experience).


The van idles perfectly and doesn’t miss it just bogs like someone cut a hole in it if I step on the gas

That's what my '85 does — right at or just above 50mph only — when the O2 sensor needs to be replaced. It's inexpensive, so a good place to start anyway.

Gwen

[zosteria]

Do you have any codes?
no codes at all

[zosteria]

O2 sensor mounts into the exhaust pipe and is before the catalytic converter (1st gen vans only have the one, and it rarely throws a code when it goes bad in my experience).



That's what my '85 does — right at or just above 50mph only — when the O2 sensor needs to be replaced. It's inexpensive, so a good place to start anyway.

Gwen
This is happening at 5 mph or whenever I change the throttle position at all, which made me think that it was the throttle position sensor I’m afraid that sort of the old it won’t start. I think it must be the starter problem where thinking too hard about the function of something makes you suspect it to the best of my abilities I think I’ve got the TPS correctly adjustedand I checked it after the whole throttlebody was installed. I’ve got continuity from when the throttle is completely closed to when it’s passing .28 how sensitive is that adjustment supposed to be? It’s going between an adjustable screw and a sheet metal arm that’s kind of rough. and I checked it after the whole throttlebody was installed. I’ve got continuity from when the throttle is completely closed to when it’s passing .28 how sensitive is that adjustment supposed to be? It’s going between an adjustable screw and a sheet metal arm that’s kind of rough. The book is kind of useless. It says that you’re supposed to have continuity at .22 but not whether you’re supposed to have it up to that point as well when the throttle is completely closed, I have continuity on those two pins. I’m gonna go ahead and order a oxygen sensor because I’ve never replaced mine and it seems like maybe it’s due any guidance on what has to be taken apart to get to it?