Terrano surging at low revs

[sibainmud]

Simon! That hose is partially clean! What a disgrace!

Doodling while talking on the phone.
Can assure you it's not clean now

[R_ace-link]

Hi Race, no I'm sorry I don't know about the turbo off-hand. I think mine's covered up too but will have a look and see what I can this w/end.

Your issue could still be timing, or some other issue with that inj pump. I made up an adapter to fit my dial gauge and timed it according to the book. Your description of problems is much like a timing fault. If it's too far retarded it will blow smoke and idle roughly, if it's advanced a little it will improve but can still be hard to start until it's right. To advance it you turn the pump away from the engine - possibly worth a try (it might be worth finding out what exactly your nephew did to the pump that made such a difference previously).

If I have time to get my tacho sorted I'll let you know what's needed.

Lucky you with the manual, my preference too but none available and I'd probably go Toyota on that anyway...

Cheers, P.

Just found out he adjusted it by advancing the timing a little( so the pump can't be the fault). he told me it could be the injectors and that the slow cranking could be that the starter motor is on it's way out

great, let me know if you got your tacho sorted , oh and if you got the turbo serial number would you let me know too. that's when I could start looking for a replacement turbo, if mine fails.

yep.. I love the manual, you got more grunt with a manual then a auto.

regards,
R

[R_ace-link]

That TD27eti is out of a Mistral. They were the only ones to have a top mount intercooler, the R50 Terrano have a front mount cooler. I have retro fitted one of these coolers to my standard TD27t. See the similarities.


Your problem could be an injector. When it is running on 3, loosen each injector pipe in turn to see which cylinder is causing the issue. The one that makes no difference is the problem one. Eti engines have a sensor in number 1 injector that is hooked to the ecu.
PM TD Power, with the turbo and pump questions. He eats, breaths and shyts Nissan diesels

Cheers,

I'll replace the injectors by the end of the month (I hope). only when cold starting it acts like it's running on 3 cylinders, but when hot it idles smooth, but you can feel a little hiccup though.
so it's a mistral engine
does it differ from the terrano? like performance??? HP?? torque??
or is it the same engine
do you know what turbo they used on these engines?
so I could start looking for a replacement, if I blow this one up

[sibainmud]

Same Same.
TD Power has a couple of these turbos in his old mans wreckers yard (well last time i was there)
They are off a Post 97 mistral (the one with the round headlights)
Hope this helps.
Cheers,

[u13turbo]

That TD27eti is out of a Mistral. They were the only ones to have a top mount intercooler, the R50 Terrano have a front mount cooler. I have retro fitted one of these coolers to my standard TD27t. See the similarities.


Your problem could be an injector. When it is running on 3, loosen each injector pipe in turn to see which cylinder is causing the issue. The one that makes no difference is the problem one. Eti engines have a sensor in number 1 injector that is hooked to the ecu.
PM TD Power, with the turbo and pump questions. He eats, breaths and shyts Nissan diesels

Cheers,

I'll replace the injectors by the end of the month (I hope). only when cold starting it acts like it's running on 3 cylinders, but when hot it idles smooth, but you can feel a little hiccup though.
so it's a mistral engine
does it differ from the terrano? like performance??? HP?? torque??
or is it the same engine
do you know what turbo they used on these engines?
so I could start looking for a replacement, if I blow this one up

At a guess, have you checked compression? My mates terrano idles really rough on startup, and blows a little blue smoke, after about 1 minute its fine, and one of the cylinders has low compression, im guessing once the rings warm abit they expand giving better compression.

[R_ace-link]

well, I haven't really thought about that!
I guess I have to find a garage that can do a compression test then..huh! right now my budget is a whee bit tight, so I'ma leave it like that for the moment.

race

[R_ace-link]

hey guys,

just got the boost gauge and I it was boosting around 11psi.
I now adjusted it to 14 psi and goes like umph! adjusted the fuel screw by a 1/4 turn too. now when planting your foot down and driving like there's no tomorrow the fuel needle really goes down real fast too

oh..yeah it still takes a while to start though, haven't come around to having the injectors, inj pump tested and starter rebuild.

phaedrus, did you get your tacho sorted yet???

regards
race

[phaedrus]

Good to hear you've got it going better!

I've not had a chance to look at the tacho yet unfortunately, still rather busy playing with earthquakes 'n structures right now

That said I'd like to get it sorted so must have a look at it soon.

P.

[phaedrus]

Well it's taken a while but I got the tacho working today. I'll be using the vehicle next week (I've had the Mistral on the road for the past 6 months) so thought I'd better sort a few things out with it.

In order to make the tacho work it requires a pulse to be fed to the ECU from a sensor that is ordinarily located on the side of the electronic injector pump. The mechanical pump doesn't have one so the pulse needs to be obtained elsewhere.

In this case to test it out I applied a pulse using a function generator and found that an 18hz signal equated to 500rpm on the tacho. This in itself meant a little over 1000 pulses/min (or 2 x crankshaft speed).

Obviously one needed to locate a suitable source of pulses, or create a system for producing them - say a couple of magnets glued to the front crankshaft pulley with a sensor close by. As it turned out however the crankshaft position sensor (CPS) when connected to the tacho (via some clip leads since the plugs are different) was found to work perfectly!

So in order to have the CPS provide the tacho pulses as well as do its own job I connected the outer red lead of the CPS engine mounted socket to the outer (blue) lead of the tacho sensor socket via a 0.1uf capacitor.

The central pin of the three-pin connectors for the CPS and tacho sensor connectors are common so just the single lead is required. I used the capacitor to DC isolate the two inputs just in case it caused any problems. I suspect the inputs already have caps but it didn't hurt to do this. Incidentaly anything less that 0.1uf may not work.

So now the tacho works happily and the ECU sees the CPS pulses as it should also.

If this were a manual vehicle the story would end there but unfortunately it's an auto so more needed to be done with that side of things. I'll start another thread perhaps but I've learnt somewhat more about the ECU/TCU, sensors and the electro-mechanical fuel pump that may be of interest to those wanting to mess with these things.

In particular I'm suspicious of the need to completely replace the 'electronic module' when overhauling these injector pumps....

[phaedrus]

I now have the auto working correctly so for anyone contemplating this mod I can confirm it's possible to do without much difficulty.

If you change over the pump, and have an auto, you need to ensure the replacement mechanical pump has the TPS fitted to the throttle shaft at the top of the pump. If the replacement pump is from an auto it should have this. To make a neat job it would pay to get the other side of the plug and a length of the associated wiring.

The TPS has a ~5k pot and a ganged min/max throttle switch so six conections in all.

This TPS needs to be connected to the original TPS wiring at the base of the 'A' post/firewall intersection inside the cab. In my case I ran a short section of 6-wire cable between the pump TPS plug/socket and the accelerator pedal TPS wiring (hope that makes sense!). I cut some fine strips of 22g galv sheet and soldered the wires to these and pushed them into the existing sockets. This meant that should anyone wish to restore the car to full 'electronic' operation it's a simple matter of unplugging this cable and fitting back the original accelerator pedal TPS.

I've not made a note of the specific wiring colours but using a multimeter you can ensure you connect the pot to the right socket and the switch to the other (ie. compare to the original).

Some judicious adjustment of the TPS position at the pump top will have the auto shifting as you desire. Given that in this case the TPS is not functioning as the motor throttle control it would also be possible to connect up and fit a further pot in the cab for the driver to easily adjust the shifting pattern to suit their driving style on the run.

I'm not certain that the TPswitch connections are required since the pedal box already has a min position accelerator switch fitted. It may need the max position switch for the kick-down to work although this would not be technically necessary. It's a simple job to check this out and when I have a moment I'll try it out & report back. If it's not required then that simplifies things somewhat and just a three-wire cable/connection would be all that's needed.

P.

[R_ace-link]

Hi Phaedrus,

it's been awhile.
You kinda lost me there ! something about getting a pulse from somewhere? do have any drawing which I can follow?
I'm not that electrically minded.


there is a sensor in the front of the mistral engine, just above the waterpump. which sensor is that??? can you get a pulse from that sensor??

Anyways, I need to replace my headgasket. bcuz of pressure building up in the radiator.

cheerios

[phaedrus]

Hi Race.

There should be a crankshaft position sensor (CPS) at the front of your motor. If you have a multimeter and are able to measure it should read about 1.6k ohms. In the case of the Terrano motor there are three leads coming from it, one of which is not needed.

On my Mistral ('95, manual pump) the sensor is located at the base of the injector pump gear housing which is to the left lower section of the motor looking from the front. This is the true tacho sensor really although as long as the gear doesn't slip it will indicate crankshaft position.

On the Terrano motor (which in this case uses the later front covers and so is effectively the 'electronic' motor and perhaps the closest to yours) the CPS is adjacent to the right upper upper quadrant of the water pump looking from the front. It has a tab to the side with a bolt that retains it against the housing and the sensor itself is probably 20-25mm or so in diameter from memory. Hopefully this is the sensor you've seen.

If you're not using the sensor for its intended purpose then you could simply connect it directly to the tacho input, there's no need to use the capacitor as I did. That was part of my research into the issue and a nicety to keep the ECU (marginally!) happy. In your case I imagine it would be ok to simply swap it over to being a tacho sensor. You only need two of the three leads (assumng yours has three), I think I put the colours in my previous post? Essentially although the plug and socket may not properly mate they should be similar enough to orientate to see which leads should be electrically connected together.

Let me know if that's enough to tell you what to look for and if you get it working ok.

Cheers, P.

[R_ace-link]

Hey P,

now that's some info I can work with.

Much Respect.

From memory, I think the sensor on the engine does have 3 wires.
I'll let you know if I got my tacho working.

thanks P

[59bonnie]

Hi Guy, I'm new here and am having a similar problem I started a new topic here:

viewtopic.php?f=25&t=45061&p=452655#p452655

Maybe someone can add to it, many thanks, Bushy