That sounds great man. I wish I had more 4zd1/4ze1 to work on. I've learned quite a bit more since I made that video so if you have any questions please ask.
Yippy. Looking for videos in 89 troopers. Just picked one up with the 2.6 4 cylinder. It leaks oil I need to fix that. I heard the distributor is notorious and it looks like there is a good amount under it. Also the valve cover. But there is supposed to be a new one just installed
My original distributor was leaking through the seal into the cap and rotor. I bought one for around $300 from AutoZone. A reproduction of the original. It was made in Italy and started leaking under the cap within a year worse than the original Japanese from 1989. Took it back for the lifetime warranty and got a replacement. This time made in Taiwan and it's still doing well. So if you do get a new one try to see where it's made first. I'll probably rebuild the original sometime. The distributor is where the ECU gets the crank position and I think rpm so it's important to have one in good working order.
Thanks! I was just working on my trooper today. I've learned a lot since I've made this video so I wonder if it's time for me to make another quick one.
@@nicholasbottini8731 I had a Jeep or Toyota truck for years and just recently picked up an 89 Trooper with a 2.6. I'm always into learning more about them, so any instructional videos would be great. Just wheeling is fine too.
Yes!! Please do. Can I request setting/adjusting the valve lash? Just picked up a Trooper that's got 60K miles since last checked and I really want to get in and check it out. I've got a manual and have checked in a Planet Isuzu. Not quite confident just yet and the weather here is crap for street parking work. Thanks for this video it was great @@nicholasbottini8731
@@getsducks727 Do you have a stock cam? I put one in that has overlap so the procedure for adjusting the valves is a bit different with cams with overlap vs stock. But I don't think that matters much when it comes to the actual valve lash. And I believe it's.008" for all the valves.
I've got a stock cam in it. Yup, .008" for both. I've got another head with a cam from Jerry Lemond and he says .008 intake and .010 exhaust. What does it mean to have a cam with overlap? @@nicholasbottini8731
I had a start and within two seconds stall condition. After 4-5 trys it would go NP. Had an extra fuel pump relay so I popped it in and good on startup now.
I am troubleshooting a Code 25 on my 1989 Isuzu Trooper. The code references MAT Sensor, Vacuum Switching Valve{4}{9}, MAT Sensor, High Temp{7} , Intake Air Temperature sensor voltage high - turbo, 1989 to 1995 1.6L, 1.8L, 3.2L vehicles and the AIR VSV circuit failure. I think you showed the VSV and the vacuum circuit. What is the MAT Sensor ?
I've never worked with the Isuzu diesel engines but a search online shows a MAT sensor is manifold air temperature. Some California gas versions had MAP sensors(manifold absolute pressure) but I haven't run across one with a MAT sensor. The first thing I would do is try replacing the sensor itself and resetting the ECM. Other than that what would cause manifold air temperature to be too high? You have a turbo so if the waste gate is letting the pressure build up too much that could be a possibility but again I haven't worked with the turbo diesels. Let me know how it's going.
Nick, great info! I'm currently trying to diagnose why my 91 runs like crap... I hate how vacuum dependent these engines are. I can't get mine to respond to throttle with any regularity. I have to feather the pedal just to get it to run. Ever run into anything like that? Thanks for posting.
That sounds like an intriguing problem. Can you elaborate on how you can't get the engine to respond to the throttle with any regularity? If you gun it, does it rev up or stall? For the sake of performing tests while it's running, why don't you back the idle screw out on the throttle body so you don't have to feather the pedal.
@@nicholasbottini8731 the vehicle sat for 4 years and I found that the fuel had turned into basically turpentine... Replaced pump and filter. It fired right up and idled for about 30 seconds before it died. Next attempt it would start if feathering throttle. If you stomped on the throttle it will big and die. The only way to get it to rev up is by nursing the throttle... Could get to hold about 2k rpms and it sounds great. Let off any and it drops to idle for a split second and then dies. Cleaned TBI, and replaced parts mentioned to no improvement. Thanks for the help. I'll post vid on my channel.
@@MrBowNaxe Looking forward to seeing it. Good job on replacing the pump, that's quite a project especially if half the bolts on the tank were seized like mine were. Do you have a vacuum gauge? I've had my engine behave similar to yours when a large vacuum tube fell off the port. There's one going to the idle air control and it goes through the middle of the ITEC. Sometimes it's helpful to take off the passenger wheel and remove the rubber flap so you can inspect some of the lines from that angle. I replaced all the lines back when I put it together because I figured there would be some splits and leaks that would add up. I'm guessing any air that doesn't pass through the Mass Air Flow sensor will cause a lean condition. The Oxygen sensor will sense and the module can correct to some extent but if it's a big leak it can't. The power brake booster could be an issue too. Maybe it would be worth pulling that vacuum line off and plugging it. if the diaphragm is split inside it would be like having a huge vacuum leak. Did you check fuel pressure? Maybe the fuel pressure regulator is an issue. I think it's suppose to be 42 PSI without vacuum and 31 PSI with. It could be a bad Mass Air Flow sensor too. You could try taking it off the car and cleaning it with the cleaner or maybe it needs to be replaced. I was able to get one from Autozone but it took them 3 times to get me the right one. I didn't really even need to change I think I just wanted a spare. I don't thing the throttle positioning switch would cause this kind of problem for you because it's not a potentiometer style, it's just a 3 position switch. Idle, wide open throttle, and in between. I'm still not 100 percent sure what WOT position does. I'm guessing makes the mixture a little more rich. The Oxygen sensor wouldn't cause this kind of problem either because even if it wasn't working at all, it only makes slight adjustments to the mixture anyway. I hope you're making some progress. let me know.
were you able to see my video I posted on my page? I have somehow managed to have two accounts. I'm still trying to move clips from my phone and GoPro to my channel.
@@MrBowNaxe Yes I did see the videos. Have you gotten any further on troubleshooting? From the videos it does sound like it could be a timing issue. Have you checked that? Those harmonic balancers are notorious for slipping so you might think you're timed right but you're actually way off. If you take the spark plug out of cylinder number one and carefully put something in the hole like a screwdriver or if you want to get fancy and have an indicator that will fit in there. Then crank the engine by hand by putting a socket on the harmonic balancer bolt, I believe it's 24 mm. If you don't have that size socket you could put the car in forth or fifth gear and push it enough to turn the engine but it would be harder to rotate the engine slowly and accurately this way. You'll notice at some point as you're cranking it the object you have in the hole should stop coming up and then begin going down. Go back and forth until you find the point where the object is as high as it's going to get. Then check to see if your timing mark is lined up to top dead center (zero degrees). If it's significantly off you have to make a new mark for where top dead center actually is.
Both vacuum tubes come out below the chamber that says i-tec. One of the tubes then goes to the blue thermal vacuum switching valve. This valve stays closed when the engine is cold then opens when the engine is warmed up. I don't think mine was working so I bypassed it. It then goes from the blue vacuum thermal switching valve too a metal tube just above it that bends around behind the i-tec chamber and winds up near the EGR valve setup. It would then go into that back pressure transducer and so on. I think most people bypass all that anyway unless you're in California like I am. Well you still can but you have to put it back when it's smog time. Well anyway that was one of the lines. The second line goes to a plastic splitter. Then the two hoses from that splitter both go towards a vacuum switching valve on the passenger side fender. If you look at the five metal hoses going toward that vacuum switching valve, the two coming from the splitter go into #1 and #4. That's the way I have them anyway. 95% sure it's right. #1 controls the fuel pressure regulator. When the fuel pressure regulator has vacuum like when you're cruising it runs at about 31 PSI and when you open up the throttle and lose vacuum it jumps up to about 42 PS I think. Kind of like an accelerator pump on a carburetor. That one is pretty important to have configured right. #4 I think deals more with the charcoal canister. Probably not as important. It probably doesn't want to pull from the charcoal canister when it's cold or when idling or both. I did my best to explain but let me know if I missed anything or I could be more clear.
I've never actually traced it out but usually the tach gets pulses from the distributor so I assume it's ultimately coming from one of the wires in the wiring harness that plugs into the distributor. It also needs to have one wire for power when the ignition is on and probably another for ground. I think even another for when you turn the headlights on so the backlighting works. The distributor also gives crankshaft positioning to the module so there's a lot of communicating going on between the distributor and the module. If you trace the wire you might find that it Ys off to go to the module too. Just a guess.
I just got a 89. Striped every vacuum smog piece off that I could. No air pump, no egr, no heat gallery, no vacuum switching, .. Whatcha Johnny5' and see what he does..piece of mind..oh, no charcoal can either... It's all bullsh#t?.
This is the best video for these engines I've seen. I have 3 of these right now lined up for rebuilds and the vacuum is routed different in every one.
That sounds great man. I wish I had more 4zd1/4ze1 to work on. I've learned quite a bit more since I made that video so if you have any questions please ask.
Yippy. Looking for videos in 89 troopers. Just picked one up with the 2.6 4 cylinder. It leaks oil I need to fix that. I heard the distributor is notorious and it looks like there is a good amount under it. Also the valve cover. But there is supposed to be a new one just installed
My original distributor was leaking through the seal into the cap and rotor. I bought one for around $300 from AutoZone. A reproduction of the original. It was made in Italy and started leaking under the cap within a year worse than the original Japanese from 1989. Took it back for the lifetime warranty and got a replacement. This time made in Taiwan and it's still doing well. So if you do get a new one try to see where it's made first. I'll probably rebuild the original sometime. The distributor is where the ECU gets the crank position and I think rpm so it's important to have one in good working order.
Video was helpful. That's the cleanest 2.6 I've ever seen.
Thanks! I was just working on my trooper today. I've learned a lot since I've made this video so I wonder if it's time for me to make another quick one.
@@nicholasbottini8731 I had a Jeep or Toyota truck for years and just recently picked up an 89 Trooper with a 2.6. I'm always into learning more about them, so any instructional videos would be great. Just wheeling is fine too.
Yes!! Please do. Can I request setting/adjusting the valve lash? Just picked up a Trooper that's got 60K miles since last checked and I really want to get in and check it out. I've got a manual and have checked in a Planet Isuzu. Not quite confident just yet and the weather here is crap for street parking work. Thanks for this video it was great @@nicholasbottini8731
@@getsducks727 Do you have a stock cam? I put one in that has overlap so the procedure for adjusting the valves is a bit different with cams with overlap vs stock. But I don't think that matters much when it comes to the actual valve lash. And I believe it's.008" for all the valves.
I've got a stock cam in it. Yup, .008" for both. I've got another head with a cam from Jerry Lemond and he says .008 intake and .010 exhaust. What does it mean to have a cam with overlap? @@nicholasbottini8731
Isuzu mu 4ze1.
💪🔥
Awesome video, just got an 89 myself and am having a problem with it staying on when it's cold or low rpms, it will stall unless I give it some gas
There's a few things that could be. Maybe your idle air control valve. Once it's warmed up what RPM is it idling at?
@@nicholasbottini8731 it was the air intake tube, had a hole on the bottom, and the mass airflow sensor was cracked.
I had a start and within two seconds stall condition. After 4-5 trys it would go NP. Had an extra fuel pump relay so I popped it in and good on startup now.
I am troubleshooting a Code 25 on my 1989 Isuzu Trooper. The code references MAT Sensor, Vacuum Switching Valve{4}{9}, MAT Sensor, High Temp{7} ,
Intake Air Temperature sensor voltage high - turbo, 1989 to 1995 1.6L, 1.8L, 3.2L vehicles and the AIR VSV circuit failure. I think you showed the VSV and the vacuum circuit. What is the MAT Sensor ?
I've never worked with the Isuzu diesel engines but a search online shows a MAT sensor is manifold air temperature. Some California gas versions had MAP sensors(manifold absolute pressure) but I haven't run across one with a MAT sensor. The first thing I would do is try replacing the sensor itself and resetting the ECM. Other than that what would cause manifold air temperature to be too high? You have a turbo so if the waste gate is letting the pressure build up too much that could be a possibility but again I haven't worked with the turbo diesels. Let me know how it's going.
Nick, great info! I'm currently trying to diagnose why my 91 runs like crap... I hate how vacuum dependent these engines are. I can't get mine to respond to throttle with any regularity. I have to feather the pedal just to get it to run. Ever run into anything like that? Thanks for posting.
That sounds like an intriguing problem. Can you elaborate on how you can't get the engine to respond to the throttle with any regularity? If you gun it, does it rev up or stall? For the sake of performing tests while it's running, why don't you back the idle screw out on the throttle body so you don't have to feather the pedal.
@@nicholasbottini8731 the vehicle sat for 4 years and I found that the fuel had turned into basically turpentine... Replaced pump and filter. It fired right up and idled for about 30 seconds before it died. Next attempt it would start if feathering throttle. If you stomped on the throttle it will big and die. The only way to get it to rev up is by nursing the throttle... Could get to hold about 2k rpms and it sounds great. Let off any and it drops to idle for a split second and then dies. Cleaned TBI, and replaced parts mentioned to no improvement. Thanks for the help. I'll post vid on my channel.
@@MrBowNaxe Looking forward to seeing it. Good job on replacing the pump, that's quite a project especially if half the bolts on the tank were seized like mine were. Do you have a vacuum gauge? I've had my engine behave similar to yours when a large vacuum tube fell off the port. There's one going to the idle air control and it goes through the middle of the ITEC. Sometimes it's helpful to take off the passenger wheel and remove the rubber flap so you can inspect some of the lines from that angle. I replaced all the lines back when I put it together because I figured there would be some splits and leaks that would add up. I'm guessing any air that doesn't pass through the Mass Air Flow sensor will cause a lean condition. The Oxygen sensor will sense and the module can correct to some extent but if it's a big leak it can't. The power brake booster could be an issue too. Maybe it would be worth pulling that vacuum line off and plugging it. if the diaphragm is split inside it would be like having a huge vacuum leak. Did you check fuel pressure? Maybe the fuel pressure regulator is an issue. I think it's suppose to be 42 PSI without vacuum and 31 PSI with. It could be a bad Mass Air Flow sensor too. You could try taking it off the car and cleaning it with the cleaner or maybe it needs to be replaced. I was able to get one from Autozone but it took them 3 times to get me the right one. I didn't really even need to change I think I just wanted a spare. I don't thing the throttle positioning switch would cause this kind of problem for you because it's not a potentiometer style, it's just a 3 position switch. Idle, wide open throttle, and in between. I'm still not 100 percent sure what WOT position does. I'm guessing makes the mixture a little more rich. The Oxygen sensor wouldn't cause this kind of problem either because even if it wasn't working at all, it only makes slight adjustments to the mixture anyway. I hope you're making some progress. let me know.
were you able to see my video I posted on my page? I have somehow managed to have two accounts. I'm still trying to move clips from my phone and GoPro to my channel.
@@MrBowNaxe Yes I did see the videos. Have you gotten any further on troubleshooting? From the videos it does sound like it could be a timing issue. Have you checked that? Those harmonic balancers are notorious for slipping so you might think you're timed right but you're actually way off. If you take the spark plug out of cylinder number one and carefully put something in the hole like a screwdriver or if you want to get fancy and have an indicator that will fit in there. Then crank the engine by hand by putting a socket on the harmonic balancer bolt, I believe it's 24 mm. If you don't have that size socket you could put the car in forth or fifth gear and push it enough to turn the engine but it would be harder to rotate the engine slowly and accurately this way. You'll notice at some point as you're cranking it the object you have in the hole should stop coming up and then begin going down. Go back and forth until you find the point where the object is as high as it's going to get. Then check to see if your timing mark is lined up to top dead center (zero degrees). If it's significantly off you have to make a new mark for where top dead center actually is.
On the throttle body where do the two vacuum lines go
Both vacuum tubes come out below the chamber that says i-tec. One of the tubes then goes to the blue thermal vacuum switching valve. This valve stays closed when the engine is cold then opens when the engine is warmed up. I don't think mine was working so I bypassed it. It then goes from the blue vacuum thermal switching valve too a metal tube just above it that bends around behind the i-tec chamber and winds up near the EGR valve setup. It would then go into that back pressure transducer and so on. I think most people bypass all that anyway unless you're in California like I am. Well you still can but you have to put it back when it's smog time. Well anyway that was one of the lines. The second line goes to a plastic splitter. Then the two hoses from that splitter both go towards a vacuum switching valve on the passenger side fender. If you look at the five metal hoses going toward that vacuum switching valve, the two coming from the splitter go into #1 and #4. That's the way I have them anyway. 95% sure it's right. #1 controls the fuel pressure regulator. When the fuel pressure regulator has vacuum like when you're cruising it runs at about 31 PSI and when you open up the throttle and lose vacuum it jumps up to about 42 PS I think. Kind of like an accelerator pump on a carburetor. That one is pretty important to have configured right. #4 I think deals more with the charcoal canister. Probably not as important. It probably doesn't want to pull from the charcoal canister when it's cold or when idling or both. I did my best to explain but let me know if I missed anything or I could be more clear.
Hello I am trying to figure out where the tachometer wire is and where it goes anyway you could contact me
I've never actually traced it out but usually the tach gets pulses from the distributor so I assume it's ultimately coming from one of the wires in the wiring harness that plugs into the distributor. It also needs to have one wire for power when the ignition is on and probably another for ground. I think even another for when you turn the headlights on so the backlighting works. The distributor also gives crankshaft positioning to the module so there's a lot of communicating going on between the distributor and the module. If you trace the wire you might find that it Ys off to go to the module too. Just a guess.
Yeah so problem is it is disconnected lol and can’t figure out where it even is to start
@@corbinmichael1288 what is disconnected? Show some pictures if you can
I just got a 89. Striped every vacuum smog piece off that I could. No air pump, no egr, no heat gallery, no vacuum switching, ..
Whatcha Johnny5' and see what he does..piece of mind..oh, no charcoal can either...
It's all bullsh#t?.