No power. Can't drive. Won't idle above 1,500 RPMS

[MrBobDobalina]

Okay, I have been searching extensively and have found a lot of people that have pointed out fuel pressure regulators that could be bad, O2 sensors, CAT's, MAF and crank position sensors. Please take a peek at my story and my recordings of my o2 and fuel trims to see if this makes sense to any of you. Trying to get the truck on the road without experimenting with parts!! Want to buy just what is needed.

I have a 99 Limited 4x4 with a 1st generation supercharger. 200k Miles. Owned the truck the last 100k miles. California truck. No current CEL. See notes below from when I started having the issue.

For the most part, I have a bad head gasket which I know I need to get after...which leads me to believe I could've fried one of the CATs.

I have cleaned the MAF, replaced air filter and spark plugs are all good...one of them will foul from the bad HG and I replace that one often.

I was driving up a small grade on the freeway...truck just lost all power and I had to limp up the hill in the emergency lane. I live very close to the next off ramp so I was able to barely make it home. Prior to that the truck ran fine...other than HG and spark plug I occasionally replace.

Now my truck will not idle above 1,500+/- RPMS...I cannot drive it except to pull it in and out of my driveway. There is no power and can't really get past more than a few MPH.

This is a recording of my truck at idle:

994Runner Idle

Here is my truck when I try to increase the idle. I will also mention that my foot is steady on the gas and you will see that the idle will fluctuate all on its own quite a bit.

99 4Runner Increased Idle Attempt

This was from when I first had the issue:

My truck idles very smoothly. Starts up just fine...Just not drivable after that.

What do you all think?

 

[ShannanC]

Just going to throw this out there because it just happened to me. My timing belt tensioner broke and allowed the belt to jump a couple of teeth and completely assed up the timing. Ran rough and wouldn't go over 1500 rpm. Maybe this will help you out.

 

[MrBobDobalina]

I should've added, that I did tear down the front belt cover and got the crank to 0 degrees... everything seemed to line up. Was yours off a noticeable amount?

 

[heat]

Searching on limp mode suggests a P0420 can trigger it.

 

[thennen]

I’m going to throw out my first thought. Keep in mind I’m not a Toyota mechanic. The too-rich errors indicate not enough air to me. I’m no supercharger expert, but I’m guessing the electronics are tuned to look for a certain amount of air based on the engine’s current configuration. Is there a way to tell the engine that there’s no supercharger attached, then physically bypass the supercharger altogether? Or maybe it’s not that complicated - maybe you can physically eliminate possible airflow culprits by simply bypassing them one at a time. Guessing again, fuel delivery problems would typically result in too-lean errors. Please correct me if I’m off base, folks.

 

[thennen]

Sorry, gonna add really old data here. I had a 1988 4Runner with a 22RE that fell on its face in a similar fashion around 2002. Short story is that I lubed the ends of the butterfly valve in the air flow sensor (WD40) and the problem went away. It apparently had a small bind in it due to being dry. The air flow sensor was $475 I believe, so I had some motivation to experiment. This is one reason I’m focused on air flow being your culprit.

 

[alumarine]

While we're throwing ideas around I once had the exposed wires to my O2 short out and it fell on it's face too.

 

[kevinRR]

I had the same problem with my WRX, it ran sluggish, rich and gas mileage just drop. I also had the P0172, I log it and the STFT was adding fuel like crazy. I check for vacuum leaks and found nothing. It ended up being a bad MAF. If you have one lying around swap it out and see it that fixes it.

 

[LittleCaesar]

How much compression is there in Cylinder #4?

 

[4Reak Show]

Buy a vacuum gauge, and hook it up. Rev it up and see. If the vacuum is slow to respond a plugged exhaust could be the issue. Remember, an engine is just an air pump. It needs to get air in and out. If you're suspecting a plugged cat, take it out. See if the engine breathes better.

It could be a MAF that is sluggish as well. Tough to know without extensive testing. At some point, you gotta try something or invest in diag equipment.

 

[spartacus]

i would start by fixing the Head gasket! seems like a ignition system issue.your misfire on four caused by HG leak is probably causing rich condition. I would check the plugs for cracks in the ceramic also coil boots and ohm out the coils and plug wires. p0420 could be caused by the rich condition also.

 

[19963.4lsr5]

420 code can also be caused by burning antifreeze.


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[MrBobDobalina]

Sorry for the late replies everyone. Had to take off for work.

How much compression is there in Cylinder #4?

I will try and check that today. Thanks!

Buy a vacuum gauge, and hook it up. Rev it up and see. If the vacuum is slow to respond a plugged exhaust could be the issue. Remember, an engine is just an air pump. It needs to get air in and out. If you're suspecting a plugged cat, take it out. See if the engine breathes better.

It could be a MAF that is sluggish as well. Tough to know without extensive testing. At some point, you gotta try something or invest in diag equipment.

I have a mityvac gauge. I am not sure where to hook it up though. I can only rev it up to no more than 1,500 RPMS before is starts to fall flat. I was thinking about buying a MAF and trying to swap it. Or try and test mine.

i would start by fixing the Head gasket! seems like a ignition system issue.your misfire on four caused by HG leak is probably causing rich condition. I would check the plugs for cracks in the ceramic also coil boots and ohm out the coils and plug wires. p0420 could be caused by the rich condition also.

Thanks. I will check into the coils/wires. The wires I believe I bought within the last 60k miles and are OEM. I know, I have been planning on the HG repair, but need to finish some other projects in my garage so I have a place to take this apart.

420 code can also be caused by burning antifreeze.


Sent from my iPhone using Tapatalk

Yes!

While we're throwing ideas around I once had the exposed wires to my O2 short out and it fell on it's face too.

I will check the O2 Sensor wires. Thank you!

I had the same problem with my WRX, it ran sluggish, rich and gas mileage just drop. I also had the P0172, I log it and the STFT was adding fuel like crazy. I check for vacuum leaks and found nothing. It ended up being a bad MAF. If you have one lying around swap it out and see it that fixes it.

I think I am going to try that today! Thanks!!

So everyone, thanks for the replies. What is so weird is that I have had this HG issue for a while. Once my truck warms up, it drives great!! Occasionally top off the coolant and once in a while swap out that plug. So it's been very driveable. Other than when I was going up that grade and randomly, now I can't rev above 1,500 RPMS.

Does anyone notice anything strange with my O2 Sensors and fuel trim levels I posted above? Those are 15 sec recordings. Thanks again everyone!!!

 

[LittleCaesar]

One fast way to check the cat is using an infrared heat gun to measure the temp pre and post cat. Usually the temps pre cat are cooler than post cat by a good thirty degrees at least, maybe more. If it isn’t working, they will be about the same.

As [MENTION=15034]4reak[/MENTION]_Show suggests, buy a vacuum gauge and hook it up to a vacuum port on the upper manifold.

 

[MrBobDobalina]

Thanks. I will see if I can pick up a gauge today. I have a IR thermometer, I will check that as well.

 

[spartacus]

Does anyone notice anything strange with my O2 Sensors and fuel trim levels I posted above? Those are 15 sec recordings. Thanks again everyone!!![/QUOTE]

your readings indicate rich conditions,-19 is rich. your o2 sensors are fluctuating between 0.1 to 0.9 volts which is inline.you also have a system to rich cel. system to rich can be caused by dlirty or bad maf, leaking injectors, faulty fuel pressure, coolant temp sensor, exhaust leaks also camshaft timing or low compression issues like a cracked head or bad HG etc. among other things.

 

[juiceboxer]

This probably won't help much in the diagnosis but as I am in the middle of replacing what I thought was a head gasket I figured I would add some info. I had similar symptoms on startup, and an intermittent misfire code for Cylinder 4 as well. I pulled the plug and put a borescope Cylinder 4 and saw coolant. When I pulled the heads to replace the gasket I discovered the gasket was not the issue, there was a crack between the intake and exhaust valves that was causing the leak. I wouldn't say it is a "common problem" but these heads are known to crack in the same place every time either cylinder 4 or 3 depending on the side of the motor with the issue.

I bring all of this up fist to prepare you that it may not just be a head gasket, and second because its possible that you have a crack in the head that could be allowing intake air (and fuel) to pass through to the exhaust before combustion causing a rich reading from the downstream o2 sensors.

 

[MrBobDobalina]

Just wanted to post an update in case this thread ever helps someone. Turns out both of my catalytic converters were bad!

 

[thegipper]

Thanks for following up with us.

I remember reading this thread and to me it sounded like the cat was plugged up. I had very similar symptoms with my Grand Prix and that's what it was. Glad you got it fixed.

 

[MrBobDobalina]

Thanks for following up with us.

I remember reading this thread and to me it sounded like the cat was plugged up. I had very similar symptoms with my Grand Prix and that's what it was. Glad you got it fixed.

Yeah, now it's just too bad I live in California!!! Our cats are spendy! Lol.