Rusty Bottoms
Member
- Joined
- Aug 23, 2016
- Messages
- 121
- Country Flag
Hi everyone, as some of you might know, I recently picked up a rather nice looking 1988 LJ70 with the Toyota 1UZFE V8 conversion - again some of you may have recognised it as one of the forum member's old LJ builds.
From what little information I have been given, seems West Coast had it for a long time after the V8 install trying to sort some running issues, and from the receipts I have, it seems the now defunct Thor Racing had a go at solving the engine problems after it left WC. The seller didn't offer much information, I didn't ask a ton of questions really, and it had a slight misfire just off idle when I bought it. But hey, it made it home 360 miles!
Well, it drove home ok, a slight misfire in town, but ran fine in the end on the motorway and pulled like a freight train on hills only using half throttle.
I had it booked in for its MOT tomorrow (expired about three weeks ago) but ended up canceling.
Yesterday and today it is fouling all eight spark plugs like nobody's business - completely black and soot covered, and runs very rough - without the MOT I can't legally drive it to clear the plugs and it misfires pretty badly as it's loading up on fuel.
So time to get the multimeter out and start diagnosing. The engine itself is ok, compression and all that, but of course there are a ton of possible faults causing this problem - given a 25 year old complex motor with a ton of electronics plonked into a 28 year old diesel truck with lots of wires running amok...which I shall eventually tidy up in new looms.
Fun, but I figured owning it at first wouldn't be that easy.
After reading forums specifically on the 1UZFE motor, I am starting from scratch and going through the whole lot methodically, so I expect this will take some time since two garages could not fix it.
Again, it blows smoke when cracking the throttle and is running very, very rich - I bet I've only seen plugs that fouled maybe 3 or 4 times in the past 30 years. Covered in black fuzz and soot.
I started unplugging and cleaning connectors, while spraying for vacuum leaks as well. I unplugged the MAF and it stalled immediately. This apparently means it is something else, as it should default into limp-home mode if the MAF goes south, but I'm not trusting the MAF 100% just yet.
I took the ECU out tonight and will inspect the capacitors for leakage and solder new ones in if needed. From there after getting the right diagrams I will check ground connections and make sure the MAF and other sensors are getting the correct voltage. Looks like someone may have replaced the MAF, but there are two different types and the wrong one is, well, wrong!
I bet at the end of the day is it something simple, either no/low voltage to the right part, bad earth connection or something like the coolant temp sensor telling the motor it is -25C outside or a mass of gunk on the crank angle sensor...I don't think it is related to specific ignition components such as HT leads or dizzy caps (two), as all eight plugs are fouled, not four, so something is telling it to pump fuel like mad.
I don't know if anyone on here messes about with 1UZFE conversions, but it would be interesting to chat to them. Otherwise, the swap is common in Australia and New Zealand, and to a lesser extent, the states, so fortunately there is a lot of info out there for me to chew on.
If anyone has any thoughts, they are welcome to throw them out there. I WILL get this sorted as I miss driving it already!
From what little information I have been given, seems West Coast had it for a long time after the V8 install trying to sort some running issues, and from the receipts I have, it seems the now defunct Thor Racing had a go at solving the engine problems after it left WC. The seller didn't offer much information, I didn't ask a ton of questions really, and it had a slight misfire just off idle when I bought it. But hey, it made it home 360 miles!
Well, it drove home ok, a slight misfire in town, but ran fine in the end on the motorway and pulled like a freight train on hills only using half throttle.
I had it booked in for its MOT tomorrow (expired about three weeks ago) but ended up canceling.
Yesterday and today it is fouling all eight spark plugs like nobody's business - completely black and soot covered, and runs very rough - without the MOT I can't legally drive it to clear the plugs and it misfires pretty badly as it's loading up on fuel.
So time to get the multimeter out and start diagnosing. The engine itself is ok, compression and all that, but of course there are a ton of possible faults causing this problem - given a 25 year old complex motor with a ton of electronics plonked into a 28 year old diesel truck with lots of wires running amok...which I shall eventually tidy up in new looms.
Fun, but I figured owning it at first wouldn't be that easy.
After reading forums specifically on the 1UZFE motor, I am starting from scratch and going through the whole lot methodically, so I expect this will take some time since two garages could not fix it.
Again, it blows smoke when cracking the throttle and is running very, very rich - I bet I've only seen plugs that fouled maybe 3 or 4 times in the past 30 years. Covered in black fuzz and soot.
I started unplugging and cleaning connectors, while spraying for vacuum leaks as well. I unplugged the MAF and it stalled immediately. This apparently means it is something else, as it should default into limp-home mode if the MAF goes south, but I'm not trusting the MAF 100% just yet.
I took the ECU out tonight and will inspect the capacitors for leakage and solder new ones in if needed. From there after getting the right diagrams I will check ground connections and make sure the MAF and other sensors are getting the correct voltage. Looks like someone may have replaced the MAF, but there are two different types and the wrong one is, well, wrong!
I bet at the end of the day is it something simple, either no/low voltage to the right part, bad earth connection or something like the coolant temp sensor telling the motor it is -25C outside or a mass of gunk on the crank angle sensor...I don't think it is related to specific ignition components such as HT leads or dizzy caps (two), as all eight plugs are fouled, not four, so something is telling it to pump fuel like mad.
I don't know if anyone on here messes about with 1UZFE conversions, but it would be interesting to chat to them. Otherwise, the swap is common in Australia and New Zealand, and to a lesser extent, the states, so fortunately there is a lot of info out there for me to chew on.
If anyone has any thoughts, they are welcome to throw them out there. I WILL get this sorted as I miss driving it already!