93yotasr5
Come and take it
I had replaced my ECT sensor with a non Toyota brand sensor and on a longer drive in hot weather I would get a lot of “bucking” and similar issues to you. I replaced it with a Toyota brand sensor and that solved my issue.
Troubleshooting Help: '93 Sudden and Complete Loss of Power (1 Viewer)
- Thread starter IoN6
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
I suspect something in the airflow meter or the wiring and connector related to it. The connector appears to come apart when the two small screws on either end are removed. This is NOT the case and attempting it will generally wreck the meter. You can unplug the airflow meter by properly releasing the wire bail that secures it. With the meter disconnected start the truck and see if it has the same symptoms as when it acts up. If so you have found the trouble area.
There is no advance mechanism in the distributor, it is electronic advance.
So, I got it all back together. New injectors, new EGR valve and modulator, new coil. All was looking well...
Until it did it again.
This time I heard something. I heard it pinging pretty bad. I noticed that if I back out of it so it doesn't ping it is fine. But if I do not catch it in time, it just falls on its face. I have the timing set just over 3*, would say 3.5-4, running ethanol free 88 octane.
So my thought now is that the advance mechanism in the distributor is sticking. I have noticed that it feels super jerky even though I am not changing the throttle or anything else. It will go from feeling under powered to like someone hit the turbo button.
Does not seem there is anything that can be adjusted. Which means a new dizzy appears to be in my future.
- Thread starter
- #24
Interesting. Sometimes it is full on bucking others it is slight. Someone not mechanically inclined would probably not even notice it. Did Were you getting odd readings from the sensor, or just the bucking?
I received no service history with the vehicle, so I cannot say it someone prior removed the screws. I definitely did and have not though.
~2 years ago when I had to get it smog'd I did cut the cover off and adjusted the "spring" in it though. Can see what I did in this thread. I have checked all of the contacts and specs per the FSM. I will start it and unplug the VAF and see what happens. I would assume it dies. When I had the intake off to replace the injectors I wanted to make sure all of them were seated and had a good seal. Without the VAF plugged in the fuel pump does not come on.
Interesting. Really shoots a hole in my theory, but it also saved me $500.
You can advance it by following this pricedureInteresting. Sometimes it is full on bucking others it is slight. Someone not mechanically inclined would probably not even notice it. Did Were you getting odd readings from the sensor, or just the bucking?
I received no service history with the vehicle, so I cannot say it someone prior removed the screws. I definitely did and have not though.
I will start it and unplug the VAF and see what happens. I would assume it dies. When I had the intake off to replace the injectors I wanted to make sure all of them were seated and had a good seal. Without the VAF plugged in the fuel pump does not come on.
Interesting. Really shoots a hole in my theory, but it also saved me $500.
- Thread starter
- #26
@graham5david yep, that is how I set it. It is just over 3*, like the thickness of the markings over which is why I said 3.5 to 4 at the most.
- Thread starter
- #27
I received no service history with the vehicle, so I cannot say it someone prior removed the screws. I definitely did and have not though.
I will start it and unplug the VAF and see what happens. I would assume it dies. When I had the intake off to replace the injectors I wanted to make sure all of them were seated and had a good seal. Without the VAF plugged in the fuel pump does not come on.
So, when you unplug the VAF it does die. BUT, it appears you can feather the throttle and keep it running. It definitely feels like it has about 2hp when you do it though. Not really inline with what I experience when it does it on the road. It has never completely died. Just zero power.
Yesterday when I got home, I checked and there were no codes. When I unplug the VAF completely I got a 24 and 31.
I recall seeing a thread from a while back about the ECU's in the 93's having some problems. But it was not clear exactly what it was. Could it be that @cruiserdan ?
Early computers throw 85, 86 and 87 codes which relate to TCM/ECM communication issues. Codes 21 an 28 sometimes show up as well. If you comouter part number ends in 60170 or 60220 you have a problematic unit. 60221 is the updated unit
Have you washed the engine recently?
- Thread starter
- #30
Let me take a look-see what mine is.
I did pressure wash the drivers side of the block when I had it all torn apart. Given how hot is has been lately, I am pretty sure everything is dry now. And this has been going on for 2 summers now.
I would try to locate a used 60221. New ones are long gone. They were also well north of a thousand bucks when they were available. I know of a used one but it won't be cheap.
- Thread starter
- #33
Well, while I have your attention on the ECU @cruiserdan , I have an H151 sitting in my garage that I am hoping to tackle in the near future. What would be the correct P/N for a 1993 M/T ECU? I am headed to Sydney here in a few weeks for work, was going to see if I could hit a junk yard while I was out there.
[edit]
I have this P/N in my notes, but I am pretty sure I have come across at least one other M/T one as well.
89661-60200
[/edit]
[edit]
I have this P/N in my notes, but I am pretty sure I have come across at least one other M/T one as well.
89661-60200
[/edit]
For what it’s worth, there are a couple of 60221 ECUs on eBay. Not cheap, but not horrible
ecu 60221 for sale | eBay
Get the best deals for ecu 60221 at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!
www.ebay.com
- Thread starter
- #35
So, the VAF has definitely been messed with prior to me adjusting it. The little spring when it is fully closed (engine off) appears to be the shut-off for the fuel pump. Ever since I bought it, when the key was on the fuel pump was on.
Setting it to where it shuts of the fuel pump is roughly where the blue dot was. Which is 6 "clicks" from where it was when I bought it. Just ran to the store and it is running like a champ. Still feel some random hesitations, but nothing is coming up on my TOYODB reader.
Setting it to where it shuts of the fuel pump is roughly where the blue dot was. Which is 6 "clicks" from where it was when I bought it. Just ran to the store and it is running like a champ. Still feel some random hesitations, but nothing is coming up on my TOYODB reader.
Last edited:
- Thread starter
- #36
And back home. Ever so slight hesitation every now and then still. Which is hard to tell if it is the ECU backing the timing off when watching the TOYODB since it updates so slow. Going to drive it around this week and hopefully get it to pass smog. Really do not want to buy another A/T ECU since have just about all of the parts for my H151 swap.
Azca
If there is a harder way - I will find it...
The ECU may have to "learn" from the new settings. One week sounds like a good plan.
93yotasr5
Come and take it
Interesting. Sometimes it is full on bucking others it is slight. Someone not mechanically inclined would probably not even notice it. Did Were you getting odd readings from the sensor, or just the bucking?
I received no service history with the vehicle, so I cannot say it someone prior removed the screws. I definitely did and have not though.
I will start it and unplug the VAF and see what happens. I would assume it dies. When I had the intake off to replace the injectors I wanted to make sure all of them were seated and had a good seal. Without the VAF plugged in the fuel pump does not come on.
Interesting. Really shoots a hole in my theory, but it also saved me $500.
Mine was just the bucking.
- Thread starter
- #40
Passed emissions!
On the way home though, it tripped on its face. I tend to not run the AC around town and just do 2-60 air. Since it seems that everyone agrees that the only other option is the ECU, and since I am out of things I can think of, I rolled up the windows and cranked the air. Drove the whole way home in stop and go without a hitch. About half way home, I did the opposite and cranked the heat and could not get it to reproduce the problem. So maybe I am not onto something...
I am struggling with how excess ambient heat or a "hot" ECU could cause this from a logic / programming perspective... It does seem that when it loses all power the timing advance is stuck at -41.4* (which seems to be the max) according to TOYOBD app. And when before it does its thing, the timing is constantly in the -20's or more.
Have a line on an ECU locally, just waiting for conformation it is a 60221.
Code:
HC - 1.0879 / 2.5000 limit
CO - 10.7724 / 25.000 limit
CO2 - 711.7903
NOx - 4.3345 / 4.5000 limitOn the way home though, it tripped on its face. I tend to not run the AC around town and just do 2-60 air. Since it seems that everyone agrees that the only other option is the ECU, and since I am out of things I can think of, I rolled up the windows and cranked the air. Drove the whole way home in stop and go without a hitch. About half way home, I did the opposite and cranked the heat and could not get it to reproduce the problem. So maybe I am not onto something...
I am struggling with how excess ambient heat or a "hot" ECU could cause this from a logic / programming perspective... It does seem that when it loses all power the timing advance is stuck at -41.4* (which seems to be the max) according to TOYOBD app. And when before it does its thing, the timing is constantly in the -20's or more.
Have a line on an ECU locally, just waiting for conformation it is a 60221.
