FTs can be kind of weird with the tach.. the ones that came with EGR send the signal from the IP to the EGR ecu and then on to the dash. Does this engine have EGR? And what type of cruiser is it going into?
What Did You Do To Your Diesel Today (WDYDTYDT)
- Thread starter OGBeno
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
FTs can be kind of weird with the tach.. the ones that came with EGR send the signal from the IP to the EGR ecu and then on to the dash. Does this engine have EGR? And what type of cruiser is it going into?
Hmmm... That's interesting. This engine DID have EGR but I'm in the process of removing it. The engine was in an HDJ81 originally. But the engine and tach were operating normally before we tried putting in the Chinese pump. I don't think the original had an EGR ECU and I'm pretty sure if we did it did not get transplanted when the engine went in a couple of years ago. I will have a look at the EWD if I can find it. The truck where it is now is an HZJ80. Do you have any more detail about the EGR ECU and tach signalr?
And thanks!
Ah if the tach was running fine before then it must be something else.
I don't have too many details on it, I haven't really seen anyone address it in a good writeup but you'll see people mention it here and there. Also it might only be auto 80s with EGR, not sure how it works on a manual 80 with EGR.
tach not working ('97 HDFT 24V)
it's not a drama, it didn't work when I bought the truck, but I would like to get it going again. So here's the story : the tach gets its signal from the IP. the signal goes to the EGR ECU and from there to the dashboard. first I checked the ground connection. this was OK Next I measured the...
www.landcruiserclub.net
Wow. That's interesting. Thanks. The donor was a 24 VDC truck, not that I think that would have anything to do with it. Sadly the gentleman who did the swap is no longer with us so we can't ask him. I was looking at the EWD and saw this too:Ah if the tach was running fine before then it must be something else.
I don't have too many details on it, I haven't really seen anyone address it in a good writeup but you'll see people mention it here and there. Also it might only be auto 80s with EGR, not sure how it works on a manual 80 with EGR.
tach not working ('97 HDFT 24V)
it's not a drama, it didn't work when I bought the truck, but I would like to get it going again. So here's the story : the tach gets its signal from the IP. the signal goes to the EGR ECU and from there to the dashboard. first I checked the ground connection. this was OK Next I measured the...
I did not think that hall effect sensors were that delicate. Sounds like I should test the sensor itself to make sure we did not screw it up.
a good sensor/ pump combo will produce a 1.5v AC sine waveform if you have access to an oscilloscope for testing. Measure the gap between the original and the china pump is it different? does the reluctor wheel have the same number of teeth? do both sensors have the same ohm reading? 95+ non-EGR ft with automatic also have the signal converted in the auto trans module before going to the interment cluster.
Thank you for the additional info Bussman.
I opened up the old pump and counted teeth: 36 for the sensor pulse wheel and 23 for the gear that drives it. I asked the Chinese manufacturer for confirmation but still not getting that. I'm asking them for the spec sheet and color code for their wiring. I actually have a second pump from them but I don't want to risk that sensor without some information. And this was originally out of an HDJ81 which does not seem to have an electrical wiring diagram that I can find.
The thing that kills me was the engine, pump, and meter were all working correctly before I installed the Chinese pump, maybe getting the polarity wrong because the connector on the 81 was a combined 3 pin connector and the Chinese pump came with separate connectors for sensor and shut off solenoid.
I only went through this exercise because I was not happy with low end torque and thought it might be because the motor had been out of an auto transmission vehicle with the different pump calibration. I'm now having the old pump rebuilt and calibrated by the local Bosch guys but I am worried that now I have screwed the pooch on the sensor when we tried the old sensor on the new Chinese pump and again got the wrong polarity.
I'm trying to get info on denso hall effect sensors but not having any luck
The sensor shouldn't care about polarity, it is just a coil from my understanding. The tachometer, on the other hand, will be very sensitive to reversed polarity and could have been damaged if things weren't hooked up properly.
Hi AHN, here's a typical internal diagram of a hall effect sensor:
The big question is whether it has internal protection for the entirely foreseeable error of reversed wiring.
The big question is whether it has internal protection for the entirely foreseeable error of reversed wiring.
I'm not super familiar with the technical aspects of these pumps, but I was always under the impression that they used a Variable Reluctance sensor (also known as magnetic pickup) rather than Hall Effect. This would produce an AC sine wave instead of the square wave common with Hall Effect sensors, and would only require two conductors instead of three.
I think you may be right. I'm going to reassess my assumptions
I would just wait until you get the original pump rebuilt, better then taking a risk with a china pump, there is alot that could go wrong with it.
Got the original pump back from Bosch yesterday and it went in today.
- Joined
- Sep 9, 2004
- Threads
- 184
- Messages
- 13,145
- Location
- Boise - Idaho
- Website
- www.snlandcruisers.com
Here is a random thought and fact for you Cruiserheads.
Some Toyota engine specs go to the hundredth thousandth. That is .00001 which is an inch sliced in 100,000 pieces.
Ya!!
Cheers
Some Toyota engine specs go to the hundredth thousandth. That is .00001 which is an inch sliced in 100,000 pieces.
Ya!!
Cheers
I’d be curious to know what components would require tolerances like that. A hundred thousandth is a quarter of a micron, you’d be hard pressed to find a machinist that could both measure and hold that tolerance.Here is a random thought and fact for you Cruiserheads.
Some Toyota engine specs go to the hundredth thousandth. That is .00001 which is an inch sliced in 100,000 pieces.
Ya!!
Cheers
Ok, I have a puzzle for you all...
Yesterday I took the troopy with the 1HZ/safari turbo for a first drive on the highway and about 10 minutes in, this happened.
I parked as soon as it was safe.
The hoses were quite firm, and it was still full of coolant (I waited 45 minutes before opening).
When cool I drove back slowly with the heater going full blast, and the needle stayed at mid-point, never going higher.
The heater works really, really well, BTW. And this was a truck that never had a heater before. From new there was no heater. Not even holes in the firewall. I cut those myself.
My first thought was that the pump was unable to fill the engine with coolant--but then why was the heater going so well? And today we tried force circulating fluid through the head and that did not seem to be it. The other really odd symptom is that the pressure in the system is way too high. After running only a short time it is approaching 1 bar.
This engine was previously installed in Mr. Blue the 105 and had been operating normally. We freshened it and added the Safari turbo before installing in the troopy.
Today we also did the chemical test to see if maybe we had a head gasket failure but it was negative and the engine is not hard starting or smelling funny, or smoking.
The only thought I am having is that maybe we botched the plumbing somehow?
If any of you have ideas on this I'd be most interested to hear them.
Yesterday I took the troopy with the 1HZ/safari turbo for a first drive on the highway and about 10 minutes in, this happened.
I parked as soon as it was safe.
The hoses were quite firm, and it was still full of coolant (I waited 45 minutes before opening).
When cool I drove back slowly with the heater going full blast, and the needle stayed at mid-point, never going higher.
The heater works really, really well, BTW. And this was a truck that never had a heater before. From new there was no heater. Not even holes in the firewall. I cut those myself.
My first thought was that the pump was unable to fill the engine with coolant--but then why was the heater going so well? And today we tried force circulating fluid through the head and that did not seem to be it. The other really odd symptom is that the pressure in the system is way too high. After running only a short time it is approaching 1 bar.
This engine was previously installed in Mr. Blue the 105 and had been operating normally. We freshened it and added the Safari turbo before installing in the troopy.
Today we also did the chemical test to see if maybe we had a head gasket failure but it was negative and the engine is not hard starting or smelling funny, or smoking.
The only thought I am having is that maybe we botched the plumbing somehow?
If any of you have ideas on this I'd be most interested to hear them.
this is usually the headgasket (or cracked head) leaking under boost pressure causing combustion air in the cooling system, sometimes it will only leak pressure under boost (and load), check the overflow tank for bubbles while running. those gas tests on diesels are unreliable. If you have a composite headgasket it is likely the issue, not sure if 1hz got composite or mls gaskets
and if you are that high on the dash temp gauge you are near complete total meltdown, get a proper water temp gauge hooked up.... first thing
and if you are that high on the dash temp gauge you are near complete total meltdown, get a proper water temp gauge hooked up.... first thing
Last edited:
gauge, wiring / sensor problem is possible, did you happen to notice if it slowly climbed up? It's good to do a block test like that but just because it passes doesn't mean its good. might have to do other tests or get more data on under what conditions it gets hot or use another thermometer to check temps around the engine and radiator. thermal camera is even better.
exact thing happened to me once , it was the headgasket, and the test showed a false negative result,
i caught it before it got that hot though, that hot could have hurt some other things too.....
Thanks fellas. The senior mechanic was already convinced it was a head gasket. I have been doing anything I could to avoid agreeing to that conclusion and having to open the engine. We've just done that to two other diesels and I am about to head home for the holidays. Very unfortunate timing. Especially after a long stretch of work on the troopy. Was hoping to try it at high speed before heading to the US.
Just to update you all here briefly, the problem with the tach on the diesel 80 may have been a problem with the instrument cluster, not the pump sensor. We got the original pump back from Bosch and the tach continued to read low. Problem is now solved but I will post elsewhere so others can search it.
Last edited: