Lepprykaun

Okay looks like i gotta dig up my tester. But before i do that i just wanted to say something.. So i undid my airbox with the afm still attached and plugged in, i reached in underneath and played with that valve while it was still running. When i pushed it open more it idled higher but way better and smoother...... What can this mean? Maybe i do have a big vacuum leak somewhere? O_O

4Crawler

iTrader: (3)

Might be an air leak, by opening the AFM vane, you are bumping up the reading it is sending to the ECU telling it there is more air getting into the engine. So it could be if there is a vacuum/air leak letting in some unmetered air and causing the engine to run poorly, by pushing the AFM vane, ECU can compensate for the extra air.

Or it could be the fuel pump contact strip down at the bottom end is bad causing the pump to run erratically. Opening the vane pushes the fuel pump contact onto a part of the contact strip that is better and the pump now runs better. The fuel pump test jumper would tell you if this is the case.

Lepprykaun

Okay thanks. The fuel pump contact strip you speak of.. Are you talking the fuel pump relay? And i don't suppose you know where i should check for vacuum leaks that are usually a high risk?

Thanks a bunch for all this awesome info btw!

4Crawler

iTrader: (3)

Inside the AFM:
- http://www.4crawler.com/4x4/CheapTri...tml#AFMtesting

That contact in the AFM turns on the Circuit Opening Relay (COR):

- http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump
- http://www.4crawler.com/4x4/CheapTri...ORelayLocation

A popular vacuum leak check below:

Lepprykaun

If the fuel pump contact strip is faulty can this also affect fuel pressure? Because my truck has that problems as mentioned in the links you sent me where, when it sits for a few minutes after being at operating temp, it takes awhile to crank before it fires..

4Crawler

iTrader: (3)

Look a the diagram above. The AFM Fc contact is what turns on the CO relay and the CO relay sends power to the fuel pump. No Fc contact = no CO relay = no fuel pump power = no fuel to the engine. A quick ohm meter test will tell you if this is the case and likely there will be an ECU trouble code stored if this is the case (it did set a code on my '85 when I had a connection issue with my AFM).

Lepprykaun

Holy crap, so much to think about. Okay well i'll test the fuel pump test jumper and do a more thorough vacuum check on my lines. Is there a way to adjust the afm? like the valve that opens and closes?

4Crawler

iTrader: (3)

Generally not adjustable. Some folks cut open the top and adjust the internal spring pre-load to fine tune the air-fuel mixture, but other than that it is just an air vane that opens and closes with air flow.

Lepprykaun

I've tried everything i can think of.. still nothing =l

Lepprykaun

I can't locate my fuel pump test jumper either O_O

4Crawler

iTrader: (3)

Mine ('85) circled in red (driver's side fender - with jumper wire installed):


Details:
- http://www.4crawler.com/4x4/CheapTri...CheckConnector

Lepprykaun

Thanks. No luck still. Where is the cat normally located on an 85? is it right after the manifold?

4Crawler

iTrader: (3)

Underneath the floor board, right next the transmission/t-case typically.

Gamefreakgc

Ok, thread jack for just a second. I didn't know you could use carb cleaner, I've been too cheap to buy a propane torch and haven't checked. Will do that one tomorrow night! With all the vacuum hoses in a 3vz-e, I'm sure I've got at least one leak in there.



Back to the topic, 4Crawler's got you in the right direction. I think the new TPS purchase was pre-mature, you can usually adjust them and get them to work without getting a new one. You can unplug it and the engine will run, tried that when I was diagnosing a poor idle and it idled smooth without it (and very high rpm but that's normal with no TPS). So, unless unplugging the TPS cures all your issues, keep the receipt.... Installing a TPS is a pain, you'll need a ohm meter and steady hands.

Lepprykaun

Yeah carb cleaner works great!

It was definitely a spur of the moment buy and will do more research next time when i find something going wrong..

85yoat

okay guys help me out, please, i cant start a new thread cuz something about 15 post, anyways i have a 1st gen with a 22re swap, its boosted, but not the stock 22ret motor, i was sitting in it one day letting it warm up, out of no where it starts running like crap, go to give it some fuel and it dies, i can get it to idle but if i touch that throttle she wants to die and has backfired before doing so, i have checked the following..maf sensor, tps senser, cacuume lines countless times, my g pa told me to check the egr valve but i looked up symptoms of that and it sounds simalr to mine but no the same, it has fuel, but i dont know if it has enough? where do i check fuel pressure on a 22re? and what is the fuel pressure supposed to be? if you guys think of anything els please let me know, thanks

4Crawler

iTrader: (3)

See if there are any stored trouble codes:
- http://www.4crawler.com/4x4/CheapTri...CheckConnector

Sounds like an air/vacuum leak in the intake plumbing:
- http://www.4crawler.com/4x4/CheapTri...shtml#AirLeaks

reedrj

Hey,

What I have learned (the hard way) is when all else fails, it may be cheaper to ask an expert. I had the same problems with my 86. After it was down for three months of problem investigation at my local shop, I took it to a veteran Toyota mechanic who ran diagnostics and found the knock sensor to be faulty.

Fixing is only fun if I can fix it, without spending too much.