Bassmastry101

iTrader: (1)

Since you said your EFI fuse was bad that means power was cut to the ECU and cleared any codes that were stored. So you probably can't pull anything until the engine is running and the ECU has time to "relearn" it.

Did you ever figure out why the EFI fuse blew in the first place? Double check the ground at the ECU to make sure its good and make sure it has the right amount of voltage at the connector. Compare with the chart in the FSM to make sure it's all good.

But it seems like your on the right track, don't give up!

kushiel

Never did figure out what caused the fuse to go. Silly question. Where is the ECU ground? I have the passenger side kick panel off. I can see the ECU it's bolted to the body in three places.

Bassmastry101

iTrader: (1)

Should be behind it

kushiel

Check the ground for the ECU that's all good.

Idle air control valve is good and I replaced the hose from the TB to it.

When I disconnect the TPS the 4runner idles at 750 rpm and it's rough. When I reconnect the TPS is idles at 150 rpm.

VTA-E2 0.7 kOhm
IDL-E2 at 0.57mm gap is less then 2.3 kOhm by quite a bit
IDL-E2 at 0.889 or 0.83 (I don't have a 0.85 mm and no one around here seems to know where I can find one) 0.15 kOhm, should be infinite but I don't have the right thickness
VTA-E2 throttle open - within range
Vcc-E2 also within range

The spring that sits on top the DP diaphragm is a bit sticky and not very springy. Would this cause some of the problems I am seeing?

kushiel

Okies, any hints on how to remove the bottom screw on the TPS without taking part the whole throttle body?

Kiroshu

Remove throttle body.

Its best to do so anyway as it makes it much easier to adjust the TPS with the throttle body off the car.

Plus perfect time to clean the throttle body and replace the gasket ^_^

goodyota

I would check fuel pressure if you could..those tps screws are challenging not to strip but only 4 bolts and a deadblow to get the throttle body off. also, out of left feild, ive heard of fuel pump relays getting hot and randomly causing a no start cond. so i wouldnt hurt to jump the relay and see if it runs any better? hope it helps, cheers!

kushiel

After a little break I got back under the hood. I replaced the throttle position sensor, installed a new fuel filter, checked the distributor and spark plugs. The plugs are fairly new but were coated with black gunk. It looks like the engine is running rich. So here is the weird thing. The runner still idles violently at 250 rpms. The AFM flaps a lot. I put in a new AFM and same thing happened. When we adjust the idle and the throttle arm to 1200 rpm everything is fine except that it idles at 1200 rpm. It does this weird looping thing. I am not sure how to explain it. You can here the engine running at 1200 and then it drops a little and then picks back up again. Repeats over and over. This was a much bigger problem with the old TPS. We are going to take a vac gauge to the runner later this week. Has anyone had similar issues before? thanks, ara

Kiroshu

Clogged throttle body coolant passage?

Kiroshu

Compression check?

kushiel

@Kiroshu We checked the compression awhile back like a month ago but I will add that to the list.

I hadn't thought about the TB coolant passage. What part of the TB is that located on?

Kiroshu

The bottom of the throttle body you will see 2 hoses going in one on left and right....

"Black gunk" not seeing the spark plugs first hand indicates a "liquid" either gas or oil and or both entering the compustion chamber "raw."

Excessive blow-by for oil consumption? Broken piston ring(s)? Burnt valve(s)? Leaking valve stem seals... A vacuum test you said you were planning to perform will tell you alot if you know what to look for....

Blown Head gasket between 2 cyldiners...?

Internal fuel leakage into the intake... via: fuel injector.... cold start injector... fuel pressure regulator...

goodyota

hey one thing caught my eye u said..afm flaps alot. I just worked on an 85 runner and heard the same weird noise. It was because of the valves not closing all the way (too tight) so the compression was going back up through the intake on some strokes. I adjusted the valves (.008 intake and .012 exhaust) and it stopped and the truck ran alot smoother. Just to remind, engine must be at operating temp when u adjust the valves AND i put MINE at .007/.011 and it is alot quieter but probly needs adjusting more frequently. these engines do tick but i have OCD haha! hope this helps.

kushiel

@goodyota I'll give this a try too. As far as I know the values have never been adjusted or at least not recently. The insides of this runner were almost all original factory parts. Very little maintenance was done on it. The AFM flapping loudly is what is throwing me off. I hadn't thought about the valves.

kushiel

Back after a holiday with a little fiddling with the 4runner. I started the runner up this morning and it runs but the idle still loops.

So what happens is that the idle sits at 700 and then jumps up to 1100. This repeats at always at the same interval. When I drive it you can feel the vehicle pull as the idle loops up and down.

I have a feeling this is related to a faulty sensor. But not sure which one. I replaced the throttle position sensor a while ago. Any ideas?

4Crawler

iTrader: (3)

Perhaps the ECU coolant temperature sender, down below the throttle body. That or an air pocket in the cooling system causing that sender to read varying temps. That sender tells the ECU if the engine is cold (if so, increase idle speed to warm it up) or hot (if so, lower idle speed to normal).

SPARKS89

iTrader: (1)

I'm pretty sure it's the '82 Supra that's interchangeable with it. From what I've heard it's actually more of a simple upgrade, but it fits right in there with no mods....

I also wonder if it's the coolant temperature sensor. Have you burped the cooling system? You can get some pretty weird stuff happening if there's an air pocket caught in there.

kushiel

I'll recheck the the coolant temp sensor. I think I replaced it awhile back but need to check my notes.

Sorry silly question. How do I burp the cooling system?

SPARKS89

iTrader: (1)

Get it facing uphill on an incline, open the radiator cap and let it run for a bit. If bubbles are in there they will work themselves out. It's also good to bounce the front end too to work stubborn bubbles lose. Jumping on the bumper worked for me.

kushiel

I burped the runner this morning. A single bubble came out. Still doing the same looping rpm thing.

I have a second ECU coolant temp sensor that I swapped in. This on is from a parts yard. Both sensors read the same resistance. However (I forgot to mention this above) ever so often the temperature gauge inside the runner drops to zero and then jumps back up. Could both ECU temp sensor be bad? Or is there something else I should check.

Thanks!
ara