Engine shutter and rough idle (1 Viewer)

[feralyouth]

Ok everyone I am looking for advice…
I am a first time 80 owner. She’s a 95 with 160k. Anyways I noticed a while back that sometimes I would get a rough idle/shake. Thought nothing of it. Few months go by I get an O2 fault. Intake hose was falling apart. Got a new hose, new air filter, spark plugs, wires, and new fuel filter. Ran great for a few months. Then it started intermittently again but now in when Idle sometimes it gets a horrible shutter, whole vehicle shakes. I’m thinking maybe clogged injectors. I know my egr vacuum solenoid is bad so I have one coming. It’s raining but I did a Quick Look around all hoses seem fine. Im waiting to check engine mounts and exhaust mounts.
I saw somewhere that it could be the ecu. I’m also planing on doing a fuel injector cleaning.

Other notable things is I did the 7prong mod. Just put in a 2.9” lift. New touch screen radio that has been recently turning off and on a few times. No codes. Idk if the rpms are higher.

 

[BILT4ME]

Continue to shoot the parts cannon at it.

You'll find it eventually.

What brand and types of parts did you install?
Did you change the other O² sensor?
Have you ever changed your valve cover gasket and spark plug tube seals? Remove your oil filter cap while it's running and it should nearly die. And if it continues to run fine, then you need to go back and search for vacuum leaks.

 

[feralyouth]

Continue to shoot the parts cannon at it.

You'll find it eventually.

What brand and types of parts did you install?
Did you change the other O² sensor?
Have you ever changed your valve cover gasket and spark plug tube seals? Remove your oil filter cap while it's running and it should nearly die. And if it continues to run fine, then you need to go back and search for vacuum leaks.

Haven’t change O2 sensor but it was working and notified gave me a fault as I had a crack in my intake hose.. haven’t replaced cover gaskets or spark plug seals. I will try that tomorrow. I’m also going to check all mounts because I forgot to mention a hard shift sometimes

 

[jjdeneen918]

Is it only when cold, or at operating temps?

 

[LandLocked93]

Are the rpms dropping when it shakes? Like to 200rpm or thereabouts?
Or are they staying put @600 (idle speed) or so when the shaking is present?
Or is the shaking present regardless of rpm when it happens?

 

[feralyouth]

Is it only when cold, or at operating temps?

Running temps

 

[feralyouth]

Are the rpms dropping when it shakes? Like to 200rpm or thereabouts?
Or are they staying put @600 (idle speed) or so when the shaking is present?
Or is the shaking present regardless of rpm when it happens?

RPM is dropping. I tried adjusting/cleaning TPS and adjusted to about 658-630 rpm on warm idle park. Drove 15 miles 65mph and lots of stops, she sounded great, thought it was fixed. Went to an event for a few hours, started up and drove fine, high way was fine, but then had RPM dropping to 450 when coming to a stop and even died when going into reverse in drive way.

 

[OfficialGamings]

From what I have read. You are experiencing this while at Operating temperature, Or as you refer too as Running temperature.

While you also have a O2 Sensor code. When O2 Sensors are in Open loop (While the truck is warming up) The ECU has a base fuel/air map ratio (From what I remember)

Now when in closed loop (Operating temperature) The O2 Sensors feed information back to the ECU for fuel/air map ratios.

If you do have a faulty O2 Sensor this could be a issue. ? Someone with abit more knowledge can hopefully chip in on this.

I have also had a similar issue with a VAF on the 1993, But I believe the 1995 just got the new MAF sensor upgrade

 

[jjdeneen918]

Running temps

Interesting. I’m having these same issues, but while getting to operating temp.

After it gets to 110-120* and higher, this issue goes away.

 

[feralyouth]

From what I have read. You are experiencing this while at Operating temperature, Or as you refer too as Running temperature.

While you also have a O2 Sensor code. When O2 Sensors are in Open loop (While the truck is warming up) The ECU has a base fuel/air map ratio (From what I remember)

Now when in closed loop (Operating temperature) The O2 Sensors feed information back to the ECU for fuel/air map ratios.

If you do have a faulty O2 Sensor this could be a issue. ? Someone with abit more knowledge can hopefully chip in on this.

I have also had a similar issue with a VAF on the 1993, But I believe the 1995 just got the new MAF sensor upgrade

I get what you are saying. I have already ordered both O2 sensors. I figured why not replace them.

I also have a new TPS on the way, just in case.
Also a new charcoal canister for the excessive fuel tank pressure.

 

[Brindleboxer]

Honestly, you need to download the FSM (resource section) before continuing with any further repairs. Although, @BILT4ME was using some sarcasm his post still stands true. Throwing parts is not an economical or smart way to fix your issues and will likely have you regretting the cost of ownership.

Now, you need to address one issue at a time. Taken from your post, you are dealing with multiple issues.
1. O2 sensors, what code do you have?
2. Charcoal canister, extreme pressure when opening the gas cap. Address this sooner rather than later because it can cause more costly issue (cracked fuel tank) if left unattended.
3. Rough idle/shake, original compliant.
4. EGR solenoid, use the FSM and test it to ensure you need a new one. If you already have the part and are adamant about replacing, do that.
5. Hard shifts

Lastly, since you have multiple issues you need to address one thing at a time. You will never know what resolves your issue if you replace several items at once. Most of the items listed above can be tested per the FSM and if you follow the applicable troubleshooting section than you know, through a methodical process established by the Toyota engineers, that you have ensured that system/component is within the factory specifications.

 

[Rollinns]

Have you replaced the distributor cap and rotor?
Fairly cheap, easy to do and not a waste of money or time to replace them after all these years.

Mine had an intermittent rough idle and replacing the cap and rotor made it run silky smooth again.

 

[feralyouth]

Honestly, you need to download the FSM (resource section) before continuing with any further repairs. Although, @BILT4ME was using some sarcasm his post still stands true. Throwing parts is not an economical or smart way to fix your issues and will likely have you regretting the cost of ownership.

Now, you need to address one issue at a time. Taken from your post, you are dealing with multiple issues.
1. O2 sensors, what code do you have?
2. Charcoal canister, extreme pressure when opening the gas cap. Address this sooner rather than later because it can cause more costly issue (cracked fuel tank) if left unattended.
3. Rough idle/shake, original compliant.
4. EGR solenoid, use the FSM and test it to ensure you need a new one. If you already have the part and are adamant about replacing, do that.
5. Hard shifts

Lastly, since you have multiple issues you need to address one thing at a time. You will never know what resolves your issue if you replace several items at once. Most of the items listed above can be tested per the FSM and if you follow the applicable troubleshooting section than you know, through a methodical process established by the Toyota engineers, that you have ensured that system/component is within the factory specifications.

I understand what you are saying. I am replacing one at a time. Not tripping on the money, if I find the issue then I have back ups… no codes for O2 yet, they usually take awhile to show up in my experience, if you’re lucky… charcoal canister has been replaced… egr modulator is bad. Well versed in egr do to working on the 88 runner… hard shift was due to the drop in rpm, while shifting into R and giving gas.

So basically I’m hunting the rough idle. Called a well versed shop. They stated they have been replacing a lot of IACs lately. I think I’ll start with replacing that. If it’s not that then I’ll have a back up. No big deal.

 

[effjay80]

MANY MANY moons ago my 94 had the shakes as you describe. Went away with a valve cover gasket replacement and thankfully never returned.

 

[CharlieS]

So basically I’m hunting the rough idle. Called a well versed shop. They stated they have been replacing a lot of IACs lately. I think I’ll start with replacing that. If it’s not that then I’ll have a back up. No big deal.

Before throwing an IAC (which is several hundred dollars) at it, you can remove and bench test your current one. There is a simple procedure in the FSM.

Second, and my experience isn't exhaustive, but on my rig rough idle was definitely a result of vacuum leaks great and small. I'd definitely recommend that you explore that avenue and eliminate that potential cause. There are a ton of places for unmetered air to enter the engine with failing/aging rubber components. Unmetered air results in rough idling.

Smoke testing has been a very effective tool for rooting out even the smallest leaks. I think I've finally replaced every rubber hose, tube, gasket, grommet, seal, o-ring, etc. on my engine and it runs like a top now.

I wouldn't rule out a failing IAC issue, but since they're so easy to bench test, I'd definitely take the time to do that.

Also, the IAC doesn't come with the o-ring, you need to order it separately.

And last of all, @Brindleboxer gave you really great advice in post #11. You'd do well to carefully reread that post and follow their advice.

 

[feralyouth]

Before throwing an IAC (which is several hundred dollars) at it, you can remove and bench test your current one. There is a simple procedure in the FSM.

Second, and my experience isn't exhaustive, but on my rig rough idle was definitely a result of vacuum leaks great and small. I'd definitely recommend that you explore that avenue and eliminate that potential cause. There are a ton of places for unmetered air to enter the engine with failing/aging rubber components. Unmetered air results in rough idling.

Smoke testing has been a very effective tool for rooting out even the smallest leaks. I think I've finally replaced every rubber hose, tube, gasket, grommet, seal, o-ring, etc. on my engine and it runs like a top now.

I wouldn't rule out a failing IAC issue, but since they're so easy to bench test, I'd definitely take the time to do that.

Also, the IAC doesn't come with the o-ring, you need to order it separately.

And last of all, @Brindleboxer gave you really great advice in post #11. You'd do well to carefully reread that post and follow their advice.

I’ve pulled vacuum on all hoses and tried the old carb cleaner test. No issues

 

[feralyouth]

Before throwing an IAC (which is several hundred dollars) at it, you can remove and bench test your current one. There is a simple procedure in the FSM.

Second, and my experience isn't exhaustive, but on my rig rough idle was definitely a result of vacuum leaks great and small. I'd definitely recommend that you explore that avenue and eliminate that potential cause. There are a ton of places for unmetered air to enter the engine with failing/aging rubber components. Unmetered air results in rough idling.

Smoke testing has been a very effective tool for rooting out even the smallest leaks. I think I've finally replaced every rubber hose, tube, gasket, grommet, seal, o-ring, etc. on my engine and it runs like a top now.

I wouldn't rule out a failing IAC issue, but since they're so easy to bench test, I'd definitely take the time to do that.

Also, the IAC doesn't come with the o-ring, you need to order it separately.

And last of all, @Brindleboxer gave you really great advice in post #11. You'd do well to carefully reread that post and follow their advice.

The issue was mainly the O2 sensor but my IAC did have some issues due to carbon build up, so I cleaned it and we all good.

 

[feralyouth]

Ok everyone I am looking for advice…
I am a first time 80 owner. She’s a 95 with 160k. Anyways I noticed a while back that sometimes I would get a rough idle/shake. Thought nothing of it. Few months go by I get an O2 fault. Intake hose was falling apart. Got a new hose, new air filter, spark plugs, wires, and new fuel filter. Ran great for a few months. Then it started intermittently again but now in when Idle sometimes it gets a horrible shutter, whole vehicle shakes. I’m thinking maybe clogged injectors. I know my egr vacuum solenoid is bad so I have one coming. It’s raining but I did a Quick Look around all hoses seem fine. Im waiting to check engine mounts and exhaust mounts.
I saw somewhere that it could be the ecu. I’m also planing on doing a fuel injector cleaning.

Other notable things is I did the 7prong mod. Just put in a 2.9” lift. New touch screen radio that has been recently turning off and on a few times. No codes. Idk if the rpms are higher.

Hello the answer was a bad up stream O2 sensor a long with a minor build up of carbon on the IAC that contributed.