Idle trouble and loss of power 80s series (1 Viewer)

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Joined
May 1, 2019
Threads
1
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25
Location
South Carolina
Hey y'all,

I'm new here so I ask for apologies in advance if I am asking questions that have been beat to death already or if I am posting this in the wrong place. I've searched some threads but have not found the answers I am looking for.
Backstory:
I have a 94 80s series. When I would first crank it, it would idle a little rough and I would have some loss of power down the hwy. After running a little down the hwy, it seemed to straighten itself out. I assumed it was a vacuum leak. The only leak that I could find was the #2 pvc valve. I replace it and had no change. The distributor O-ring was leaking and needed to be done, so I decided to change the button, cap, plugs, and wires while I was at it. I hoped that new plugs and wires would help solve my problems. The plugs really needed changing. They were pretty corroded and fouled. I marked everything to try to get the timing back correct and installed the new parts. Now, the engine runs much worse. It has substantial loss of power and wont even idle without shutting off. When I rev up to a steady 2500 rpms it seems to run smooth until I give it more throttle. I have several questions and a few ideas.

1) My feelings is that there is a good chance that I exasperated a problem and messed something up when I worked on the distributor, plugs and wires. I will start there and work on to something else.
a) spark plugs are NGK. the gap could be wrong. They looked right but I will recheck those tonight.
b) How are the cylinders numbered? I assume #1 is closest to the front of the vehicle, #2 is next and so on. Am I wrong? I am pretty sure I went back with the wires just like they came off but I could have made a mistake.
c) the wires could be bad. I have the CARQUEST wires with a lifetime warranty. I know I should have gotten OEM wires but I was taking a chance and anxious to get this done. I live an hour away from the nearest Toyota dealer. I may go back with the old wires to see if that changes anything. Should I order OEM wires? I know that a bad set of new wires can ruin your day.
d) the timing could be off. Would it run this badly bc of timing? I have read to put the #1 cylinder at tdc and line up the distributor like that. Do I have to take the valve cover off to do this? or take the plug out and shine a flashlight down to see?

2) There could be a unrelated problem to the whole distributor deal and it has coincidently decided to act up during this time bc of me rummaging around the intake.
a) I have taken the throttle body off and it is dirty. I plan on cleaning it. Could it be the MAF sensor causing my trouble?
b) I have found no obvious problems with any vacuum hoses but I am thinking of replacing them all. A tedious job but one I am willing to do if it gets me up and running. What else do I need to check?

Any suggestions are welcome and I am open to constructive criticism. Please understand I am not a mechanic and my mechanical knowledge is enough to get me in trouble :) but I am all about saving money. Remember, it was running a little rough before I started in on this venture but it has gotten much worse since I have worked on it which leads to more questions than answers for me. Thanks guys!
 
Download the FSM. Good info there to trouble shoot.

FSM will have spark plug wiring order. #1 is closest to radiator. Make sure plugs are wired right. I would then check timing knowing you messed with distributor. Check the throttle position sensor as well.
 
MAF sensor will not suddenly act up if you did not mess with to begin with. Check intake hose that connected MAF sensor to intake to see if there are cracks. Common issue which exhibits your symptoms. FSM has trouble shooting to verify if your MAF sensor is working.
 
I marked everything to try to get the timing back correct and installed the new parts. Now, the engine runs much worse. It has substantial loss of power and wont even idle without shutting off. When I rev up to a steady 2500 rpms it seems to run smooth until I give it more throttle. I have several questions and a few ideas.

Your timing sounds WAY off. You can't set the timing by feel, you need to use a timing light and do it per the FSM. Stock is 3 degrees advanced, however, our engines run much stronger with 6-8 degrees advanced.


1) My feelings is that there is a good chance that I exasperated a problem and messed something up when I worked on the distributor, plugs and wires. I will start there and work on to something else.

Take a breath buddy, as far as engines go these are about as simple as they get, not like a german sports car. So whatever is the culprit is something we can likely uncover relatively quickly

a) spark plugs are NGK. the gap could be wrong. They looked right but I will recheck those tonight.
b) How are the cylinders numbered? I assume #1 is closest to the front of the vehicle, #2 is next and so on. Am I wrong? I am pretty sure I went back with the wires just like they came off but I could have made a mistake.
c) the wires could be bad. I have the CARQUEST wires with a lifetime warranty. I know I should have gotten OEM wires but I was taking a chance and anxious to get this done. I live an hour away from the nearest Toyota dealer. I may go back with the old wires to see if that changes anything. Should I order OEM wires? I know that a bad set of new wires can ruin your day.
d) the timing could be off. Would it run this badly bc of timing? I have read to put the #1 cylinder at tdc and line up the distributor like that. Do I have to take the valve cover off to do this? or take the plug out and shine a flashlight down to see?

2) There could be a unrelated problem to the whole distributor deal and it has coincidently decided to act up during this time bc of me rummaging around the intake.
a) I have taken the throttle body off and it is dirty. I plan on cleaning it. Could it be the MAF sensor causing my trouble?
b) I have found no obvious problems with any vacuum hoses but I am thinking of replacing them all. A tedious job but one I am willing to do if it gets me up and running. What else do I need to check?

Slow your roll, let's tackle this logically. It's too easy to fire the parts cannon at the problem with the hope that something you do will fix the problem. Don't do that it usually ends up being very costly and frustrating. Instead, take a minute to download the FSM HERE. Spend the rest of the day familiarizing yourself with it.

Any suggestions are welcome and I am open to constructive criticism. Please understand I am not a mechanic and my mechanical knowledge is enough to get me in trouble :) but I am all about saving money. Remember, it was running a little rough before I started in on this venture but it has gotten much worse since I have worked on it which leads to more questions than answers for me. Thanks guys!

Start with the FSM. Download it and save it to your ipad, flash drive, hard drive, your moms hard drive etc. This is your bible. Upon first glance it can be confusing and clunky to navigate but the information that Mr. T put in this will help you solve any issue you ever have (provided you are patient enough to actually find it, then you need to read the information slowly enough to comprehend what it is telling you)..

Once you download the file (1994 FZJ80 FSM) and open it up start by going to thie "diagnosi" pdf. Follow this file path to get to there. C:\Users\rnelson\Downloads\1994FZJ80FSM.zip\LC FSM\Engine\Engine\Sfi System

This will tell you how to pull the check engine codes on your rig, start there and report back. Don't buy any more parts.
 
^^^^ Amen.
 
Also, did you disconnect your battery during this adventure while replacing the dizzy O-ring? If so, your engine has to re-learn it's place. This takes like 30 start/stop cycles (that's engine on-off) before they code in.

Also, you can have Toyota parts shipped direct to your house if you can wait a few days.

I use:
Another source is www.partsouq.com

That Toyota site is cheaper than I can drive 5 miles from my house. I can order at midnight, wait 4-5 days, then they are delivered to my doorstep.

Also, look up above for a club local to you ("Clubhouses") so you can find locals to help out. They will.

On plug wires, I'm going to suggest OEM. My son works for O'Reilly so we get fantastic pricing on stuff. I still choose to go Toyota on most thing because my truck tends to "spit-out" aftermarket parts like plug wires, cap, and rotor. I tried the cheap stuff and returned it because it made it worse than 10 year old OEM stuff.

Good Luck!

Do searches, everything has been done multiple times and we'll help those that are willing to listen and wear their big-boy pants.
 
On replacement parts, I'm going to suggest OEM.

Fixed it for you ;)

But seriously, @Tjs23 these cruisers may have a simple engine but they are very very picky when it comes to parts. They will reject non-toyota parts more often than not, even simple parts that you would think would be just fine. Denso, Aisin, NGK are original equipment manufacturers that Mr. T used so you can too, other than that steer clear of the rock auto or autozone specials.
 
I agree with all of the above and imagine that once you get your wiring order sorted and your timing set that it will run better.

Another possible contributor to symptoms of low/no idle can be a cracked/broken intake pipe. This is the rubber pipe that runs from the air filter to the throttle body. With age is gets stiff and cracks around the bellows. If you changed the plugs then you probably interacted with this pipe and may have made already present cracks worse, or you may have created new ones.

Pull the intake pipe and inspect. If you find cracks and want a quick/easy fix to get you going while you wait on a new one to come in you can typically clean the cracked areas really well with brake or carb cleaner (or similar) and then glue them together with "goop" (actual name on tube) then wrap the gooped areas with the silicone repair tape. Let the goop cure overnight before reinstall. This repaired pipe will probably last a long time if repaired well but it's stiff and harder to remove/install and will fail again.

The lower cost replacement tubes on amazon/ebay have gotten good reviews to my knowledge. I've been running one for a year and it's still pliable and holding up well. OE is surely better but the cheaper options are viable for this application in my opinion due to how much lower their price is.
 
Your timing sounds WAY off. You can't set the timing by feel, you need to use a timing light and do it per the FSM. Stock is 3 degrees advanced, however, our engines run much stronger with 6-8 degrees advanced.




Take a breath buddy, as far as engines go these are about as simple as they get, not like a german sports car. So whatever is the culprit is something we can likely uncover relatively quickly



Slow your roll, let's tackle this logically. It's too easy to fire the parts cannon at the problem with the hope that something you do will fix the problem. Don't do that it usually ends up being very costly and frustrating. Instead, take a minute to download the FSM HERE. Spend the rest of the day familiarizing yourself with it.



Start with the FSM. Download it and save it to your ipad, flash drive, hard drive, your moms hard drive etc. This is your bible. Upon first glance it can be confusing and clunky to navigate but the information that Mr. T put in this will help you solve any issue you ever have (provided you are patient enough to actually find it, then you need to read the information slowly enough to comprehend what it is telling you)..

Once you download the file (1994 FZJ80 FSM) and open it up start by going to thie "diagnosi" pdf. Follow this file path to get to there. C:\Users\rnelson\Downloads\1994FZJ80FSM.zip\LC FSM\Engine\Engine\Sfi System

This will tell you how to pull the check engine codes on your rig, start there and report back. Don't buy any more parts.
This is an incredible source! Thank you!
 
Also, did you disconnect your battery during this adventure while replacing the dizzy O-ring? If so, your engine has to re-learn it's place. This takes like 30 start/stop cycles (that's engine on-off) before they code in.

Also, you can have Toyota parts shipped direct to your house if you can wait a few days.

I use:
Another source is www.partsouq.com

That Toyota site is cheaper than I can drive 5 miles from my house. I can order at midnight, wait 4-5 days, then they are delivered to my doorstep.

Also, look up above for a club local to you ("Clubhouses") so you can find locals to help out. They will.

On plug wires, I'm going to suggest OEM. My son works for O'Reilly so we get fantastic pricing on stuff. I still choose to go Toyota on most thing because my truck tends to "spit-out" aftermarket parts like plug wires, cap, and rotor. I tried the cheap stuff and returned it because it made it worse than 10 year old OEM stuff.

Good Luck!

Do searches, everything has been done multiple times and we'll help those that are willing to listen and wear their big-
Also, did you disconnect your battery during this adventure while replacing the dizzy O-ring? If so, your engine has to re-learn it's place. This takes like 30 start/stop cycles (that's engine on-off) before they code in.

Also, you can have Toyota parts shipped direct to your house if you can wait a few days.

I use:
Another source is www.partsouq.com

That Toyota site is cheaper than I can drive 5 miles from my house. I can order at midnight, wait 4-5 days, then they are delivered to my doorstep.

Also, look up above for a club local to you ("Clubhouses") so you can find locals to help out. They will.

On plug wires, I'm going to suggest OEM. My son works for O'Reilly so we get fantastic pricing on stuff. I still choose to go Toyota on most thing because my truck tends to "spit-out" aftermarket parts like plug wires, cap, and rotor. I tried the cheap stuff and returned it because it made it worse than 10 year old OEM stuff.

Good Luck!

Do searches, everything has been done multiple times and we'll help those that are willing to listen and wear their big-boy pants.

i did disconnect the battery. I think this may be a firing/timing issue. Thanks for the info and links! I used to work at a body shop and we occasionally did mechanic work. I totally agree with you about OEM. We refused to buy aftermarket plug wires bc they are simply trash.
 
MAF sensor will not suddenly act up if you did not mess with to begin with.
Just as an FYI, since the original poster said his truck is a 1994, the correct name for this part is a VAF/Volume Air Flow Meter, not a MAF sensor. Toyota started the change over to MAF'sensors on Land Cruisers beginning with the 1995 model year. Which also goes along with the end of OBD1 in 1994, to the start of OBD2 in 1995.
 
Alright update. I took the throttle body off and cleaned it. It was filthy and it had some vacuum lines with crud in them. One was completely stopped up. I reassembled after checking all the spark plugs again. I then turned the distributor as far down as it would go, twisting it clockwise if you are standing on the left hand side of the vehicle. It cranked and ran without skipping. I assume this means I was off a gear with the distributor.
Since it looks like I will he resetting the timing, what do you guys recommend. What are the Positive and negative impacts of increasing the degrees from 3 to say 6-8? FYI -I run non ethanol and the highest grade gas.

Big thanks to those who has posted, given me extremely valuable resources, and have been helpful and patient!
 
Awesome man! It’s so rewarding when you figure it out by yourself. That’s what so cool about these trucks. Easy to work on.
 
Bumping timing from the stock 3 degrees to 6-8 will give you a noticeable bump in responsive and more power below 4K rpm. It is safe to do on pump gas.

These engine can supposedly safely run up to 12 degreed on regular gas. But I haven’t had good luck with anything over 10. Set it to 8 and enjoy the extra grunt.

You must follow the procedure outlined in the fsm to correctly set your timing. This includes putting a jumper across two terminals in the diagnostic port before starting your adjustment. Let me know if you have a hard time finding this.
 
Remove, readjust your distributor first. Then worry about timing.
 
I also have 94. 300k miles.
If I’m not mistaken, our engine runs a 9:1 compression. w/ that as low as it is, there’s no more than a mental job as to how HiTest gas makes it run any better than 87. In my yrs of ownership, I personally never saw better ‘running’ or gas mileage. I still get 11-15mpg 25yrs later. FWIW
 
Ok, I’m still not out of the woods. Back to square one. I thought I had found the solution to my issue but I may have been premature. The vehicle cranked and ran smooth but began skipping badly again and shut off before I could get to operating temp to set timing. So, I started over again. I found tdc on the compression stroke and lined everything up. This time I can’t even get fire. What’s the next step?
 
How did you verify you are in a compression stroke? Did you remove plug #1 and test with a screw driver or equal?
 
How did you verify you are in a compression stroke? Did you remove plug #1 and test with a screw driver or equal?
I used an old spark plug wire boot and held it to seal the number one cylinder with the spark plug removed while turning the motor by hand. You could see it sucking it in and then pushing it out on compression.
 

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