NBAProfessor
New member
So recently I went and bought myself a 1991 toyota 4runner v6 3.0. And it had some small issues with it. It always had a misfire but at the time, wasn't anything serious.
Drove the car for about a week. And the misfire got worst, and worst. Until one time I drove it for about 30 mins and the car chugged and died at a stoplight.
Once that happened we started to investigate and try to find this issue.
The person that put this engine in really threw it all together. Such as a aftermarket fan is their, but the wires are not connected.
Their is a knock sensor on top of the engine, but not plugged in correctly or mounted, its just hanging their.
Bunch of vacum leakes that we plugged up
And many more.
Anyways, we replaced the 1AT sensor, aka the air flow sensor. And that didn't fix the issue.
We smoked the engine to see where the vacum leaks where coming from, and one hose had a major leak. So we patched that up. Still misfires.
After that, we checked the timing on the distributor and everything was on the mark, weirdly enough, putting it on the CORRECT timing made it miss more then putting it just a little foward.
We did a check engine light test. And got back error code 24, 25, and 52. Listed below are the error codes and what they are.Trouble codeFault locationProbable Cause24lntake air temperature (lAT) sensor-circuitWiring, lAT sensor, ECM25Mixture control -continuously leanWiring, injector, H02S, ECTNAF sensor, intake/fue/lignition system, ECM52Knock sensor (KS) -circuitWiring, KS, ECM
We fixed the intake sensor, so thats gone. We still have 25, and 52. But I don't even know if those are causing it to misfire, what do you guys think?
The car also backfires. As misfire is causing it.
NEW PARTS!
Added spark plug wires
Added Spark plugs
Added new hose's on certain parts that where rusted, cracked, etc.
I also did two fuel injector cleaners. Still nothing.
Did a fuel injector pressuare check (i think its called that?) And it came back good. Around 40psi if i remember correctly.
I also disconnected the battery and checked that, cleaned up the connections a bit. And made sure it was good. Left it their for like 25 mins. Oddly enough, I started the car up and it ran perfectly for about 1min or so. After that it ran really bad again and started
to misfire. We thought doing that would reset the computer or something in that matter.
We also did a compression check, all are good, coming in at 175 all around and one is 165.
I'll be adding pictures here in a bit to show you what it looks like, it was clearly just thrown together
I'm asking for ANY Experts help in fixing this vehicle. This is my only vehicle and need it to run.
Thank you!
Pictures:
https://imgur.com/a/U3tG9hX
As you can see, I added some new parts. And if you look close, you can see I plugged up a lot of vacum leaks on the left side of the engine.
QUICK UPDATE:
Fixed the wires.
Fixed the Knock sensor
Fixed the crankshaft
Fixed the timing
TPS was on backwards, some how? Fixed that.
Fixed all those grounds that literally didn't do much because it wasn't a ground.
Fixed the 02 sensor that was not plugged in, and rusted.
Fixed the coolent leak. Hose wasn't clamped down all the way to the TPS sensor
After all of this, their is still a misfire. Anyone know what it might be?
Thanks!
Another quick update.
Ran out of options and brought it to a dealership that I work at, that is a toyota dealership.
Payed $65 and got these results
FROM THE TECH:
Someone has destroyed this vehicle. EGR has been removed and plugged off.
Many vaccum lines have been plugged off
PCV does not work, plugged off
Vehicle runs really poor. Fuel pressure is within spec. If I pinch the return line vehicle runs better.
Codes for TPS and knock sensor.
So many things wrong with this vehicle
Maybe we should start with fuel filter in case volume is low
Could also be fuel damper
We would need to remove intake plenum to inspect/replace
A good start would be knock sensor with new wire, Fuel filter, fuel dampner, intake boot, and pcv stuff.
---------------------------------------------------------
So with all of that being said. Its running rich, you can smell fuel like crazy, and its blowing a lot of smoke. SO should I start with the fuel filter and dampner and see if that fixes it?
Also, for some reason the knock sensor is still coming up as a code, even tho its been installed correctly. I'll double check that.
TPS sensor has a code and im not sure why. It only had a code after we messed with it and put it in the correct position.
Intake boot is a temp fix, and is fine for now.
With the PCV stuff is that a huge issue? Same with the EGR. Or should I start with the Fuel filter and dampner. I can't see it being the knock sensor thats making the engine flood itself, or so it seems.
Also here is a list of parts I need. Would anyone be kind enough to link me to some OEM cheap parts if possible? Thanks!
Fuel Filter
Knock Sensor
Sensor wire for knock
Air surge Gasket
Intake manifold gasket
Fuel gamper set
TPS sensor.
Thank you guys for all your help. Hopefully in the following days I can get her back on the street!
UPDATE:
I have a feeling it has something to do with the fuel. As you pinch the fuel return line, it runs just fine and has no misfire, anyone know what I should do? So I know its a fuel issue, and happens after the return line. AND it smells rich. Thanks.
ALSO: would like to note that the spark plug gap is .032, and that I've been trying to find this issue out for months and hired multiple mechanics and nobody has been able to find the issue. First we thought it was the mass air flow sensor so we replaced that as you can see by the updates. Also that the engine bay is much more cleaner then it was, such as the crankpully is now placed properly. And that the knock sensor is mounted. I'am no mechanic, or professional. I work at a toyota dealership with master tech's but they want me to pay a full paycheck to get it fixed. As you can see by the tech doug, at the toyota dealership. Thats what he had to say about it. Anyways hopefully someone can help, as I really would like to keep this vehicle. Thank you.
Drove the car for about a week. And the misfire got worst, and worst. Until one time I drove it for about 30 mins and the car chugged and died at a stoplight.
Once that happened we started to investigate and try to find this issue.
The person that put this engine in really threw it all together. Such as a aftermarket fan is their, but the wires are not connected.
Their is a knock sensor on top of the engine, but not plugged in correctly or mounted, its just hanging their.
Bunch of vacum leakes that we plugged up
And many more.
Anyways, we replaced the 1AT sensor, aka the air flow sensor. And that didn't fix the issue.
We smoked the engine to see where the vacum leaks where coming from, and one hose had a major leak. So we patched that up. Still misfires.
After that, we checked the timing on the distributor and everything was on the mark, weirdly enough, putting it on the CORRECT timing made it miss more then putting it just a little foward.
We did a check engine light test. And got back error code 24, 25, and 52. Listed below are the error codes and what they are.Trouble codeFault locationProbable Cause24lntake air temperature (lAT) sensor-circuitWiring, lAT sensor, ECM25Mixture control -continuously leanWiring, injector, H02S, ECTNAF sensor, intake/fue/lignition system, ECM52Knock sensor (KS) -circuitWiring, KS, ECM
We fixed the intake sensor, so thats gone. We still have 25, and 52. But I don't even know if those are causing it to misfire, what do you guys think?
The car also backfires. As misfire is causing it.
NEW PARTS!
Added spark plug wires
Added Spark plugs
Added new hose's on certain parts that where rusted, cracked, etc.
I also did two fuel injector cleaners. Still nothing.
Did a fuel injector pressuare check (i think its called that?) And it came back good. Around 40psi if i remember correctly.
I also disconnected the battery and checked that, cleaned up the connections a bit. And made sure it was good. Left it their for like 25 mins. Oddly enough, I started the car up and it ran perfectly for about 1min or so. After that it ran really bad again and started
to misfire. We thought doing that would reset the computer or something in that matter.
We also did a compression check, all are good, coming in at 175 all around and one is 165.
I'll be adding pictures here in a bit to show you what it looks like, it was clearly just thrown together
I'm asking for ANY Experts help in fixing this vehicle. This is my only vehicle and need it to run.
Thank you!
Pictures:
https://imgur.com/a/U3tG9hX
As you can see, I added some new parts. And if you look close, you can see I plugged up a lot of vacum leaks on the left side of the engine.
QUICK UPDATE:
Fixed the wires.
Fixed the Knock sensor
Fixed the crankshaft
Fixed the timing
TPS was on backwards, some how? Fixed that.
Fixed all those grounds that literally didn't do much because it wasn't a ground.
Fixed the 02 sensor that was not plugged in, and rusted.
Fixed the coolent leak. Hose wasn't clamped down all the way to the TPS sensor
After all of this, their is still a misfire. Anyone know what it might be?
Thanks!
Another quick update.
Ran out of options and brought it to a dealership that I work at, that is a toyota dealership.
Payed $65 and got these results
FROM THE TECH:
Someone has destroyed this vehicle. EGR has been removed and plugged off.
Many vaccum lines have been plugged off
PCV does not work, plugged off
Vehicle runs really poor. Fuel pressure is within spec. If I pinch the return line vehicle runs better.
Codes for TPS and knock sensor.
So many things wrong with this vehicle
Maybe we should start with fuel filter in case volume is low
Could also be fuel damper
We would need to remove intake plenum to inspect/replace
A good start would be knock sensor with new wire, Fuel filter, fuel dampner, intake boot, and pcv stuff.
---------------------------------------------------------
So with all of that being said. Its running rich, you can smell fuel like crazy, and its blowing a lot of smoke. SO should I start with the fuel filter and dampner and see if that fixes it?
Also, for some reason the knock sensor is still coming up as a code, even tho its been installed correctly. I'll double check that.
TPS sensor has a code and im not sure why. It only had a code after we messed with it and put it in the correct position.
Intake boot is a temp fix, and is fine for now.
With the PCV stuff is that a huge issue? Same with the EGR. Or should I start with the Fuel filter and dampner. I can't see it being the knock sensor thats making the engine flood itself, or so it seems.
Also here is a list of parts I need. Would anyone be kind enough to link me to some OEM cheap parts if possible? Thanks!
Fuel Filter
Knock Sensor
Sensor wire for knock
Air surge Gasket
Intake manifold gasket
Fuel gamper set
TPS sensor.
Thank you guys for all your help. Hopefully in the following days I can get her back on the street!
UPDATE:
I have a feeling it has something to do with the fuel. As you pinch the fuel return line, it runs just fine and has no misfire, anyone know what I should do? So I know its a fuel issue, and happens after the return line. AND it smells rich. Thanks.
ALSO: would like to note that the spark plug gap is .032, and that I've been trying to find this issue out for months and hired multiple mechanics and nobody has been able to find the issue. First we thought it was the mass air flow sensor so we replaced that as you can see by the updates. Also that the engine bay is much more cleaner then it was, such as the crankpully is now placed properly. And that the knock sensor is mounted. I'am no mechanic, or professional. I work at a toyota dealership with master tech's but they want me to pay a full paycheck to get it fixed. As you can see by the tech doug, at the toyota dealership. Thats what he had to say about it. Anyways hopefully someone can help, as I really would like to keep this vehicle. Thank you.
