Making a new loom

[AJRFulton]

As said on my other thread, I've been having intermittent lift issues on 3 different engines, and also getting a bit of sputtering at high revs which again, via elimination - is probably a good guess that it is a dodgy connections. Also when installing this engine it was noted that the alternator was working intermitted and replacing the wire fixed it.

With doing competitive motorsport the engine(s) have been out and in a lot (I can recount 9 times in the last 30 months) - and every time, no matter how careful you are, you will crush or snag something, so it is no real surprise the loom is starting to cause issues. The current loom has became a bit of a Frankenstein's monster, with repaired wires, etc.

Anyway I've ordered 5m lengths of 24x different coloured 16A wires, and 10x different coloured 5m lengths of 24A wire - as well as a length of 240A rated wire for the alternator and starter.

Through various engines I have 3x looms lying about as well as the one in the car - so between them I should have enough good clips

My question is..... what replacement pins for the clips should I purchase. I'm doing this from an oil rig, so can't just go out and look - but would like the stuff waiting on me for the 5 day window I have to do it.

My brother in law is a self employed industrial spark, so well sorted for quality crimps and what.

[mr2garageswindon]

If you are losing lift I would be paying attention to the oil temp sensor wiring as without that working properly you wont get lift.. Just a thought.

[AJRFulton]

If you are losing lift I would be paying attention to the oil temp sensor wiring as without that working properly you wont get lift.. Just a thought.

It is intermitted - it works on the rolling road, but additional vibration on track it cuts out more often than not. It is the type of issue that I could be chasing my tail with for a long time. I'm fairly certain now it has to be a wiring issue, everything else that is likely is either new or eliminated - I would agree that this is one of the likely culprits - 20yr old, <1mm single core wire going to these, so really no surprise if it proves to be that.

[mr2garageswindon]

Would it be worth finding the resistance of the sensor when up to temp and fitting a resistor instead?

[Dev]

 I would check the lift oil control solenoid valve wiring/contacts  and the actual OCV valve. That is what directs oil pressure to lock the pins allowing for the high cam pads to push the valve for increased lift and duration.
 Most solenoid motors act up when things get hot. I would remove and test the lift OCV or just get a known working valve and see if it fixes the issue.
 I would also check the lift bolts just to rule them out as intermittent lift is usually attributed to that.

[AJRFulton]

I would check the lift oil control solenoid valve wiring/contacts  and the actual OCV valve. That is what directs oil pressure to lock the pins allowing for the high cam pads to push the valve for increased lift and duration.
 Most solenoid motors act up when things get hot. I would remove and test the lift OCV or just get a known working valve and see if it fixes the issue.
 I would also check the lift bolts just to rule them out as intermittent lift is usually attributed to that.

All these parts are brand new on this engine build.

Only top end bits that are not new, is the actual cast metal head, the cam journals, out of the 24 rocker arms I have - I picked the best 8 and the rocker arm oil shaft. All cleaned and all in spec. Rocker arms are the only internal moving part that is not new.

Did it on previous engine too, and the previous engine as well - which is why I think the loom is likely culprit.

[Dev]

I would check the lift oil control solenoid valve wiring/contacts  and the actual OCV valve. That is what directs oil pressure to lock the pins allowing for the high cam pads to push the valve for increased lift and duration.
 Most solenoid motors act up when things get hot. I would remove and test the lift OCV or just get a known working valve and see if it fixes the issue.
 I would also check the lift bolts just to rule them out as intermittent lift is usually attributed to that.

All these parts are brand new on this engine build.

Only top end bits that are not new, is the actual cast metal head, the cam journals, out of the 24 rocker arms I have - I picked the best 8 and the rocker arm oil shaft. All cleaned and all in spec. Rocker arms are the only internal moving part that is not new.

Did it on previous engine too, and the previous engine as well - which is why I think the loom is likely culprit.

I would still check the wire that feeds the lift OCV that runs from the harness to the ECU. That is what makes lift possible unless there is a mechanical fault with the lock pin in the rockers. If you trace where on the ECU that wire plugs into you can use a multimeter to measure the resistance between the the wiring harness side to the engine side where the clip plugs into the OCV and measure the resistance. That would give you a clear indication if the  harness wire is good. It could be something as simple as a bad contact.

 Since you have already decided to remove the harness and redo all of the wiring you can still do this for all of the wires so you know for sure the harness is bad. I always find it satisfying finding where something has failed by diagnosing it that way I am 100% certain the fix will cure the issue. Good luck and I hope the issue is resolved.



 

 


 

[Petrus]

My question is..... what replacement pins for the clips should I purchase. I'm doing this from an oil rig, so can't just go out and look - but would like the stuff waiting on me for the 5 day window I have to do it.

The car has a bewildering variety of different connectors and as you know most have their own specific male/female pins. Afaik there is no generic female/male pin combo on the car.
The way I see it you have two options: Either go OEM connectors and pins or go generic electric/electronics connectors and pins. The latter is the most flexible by far as you will be making your own loom anyway. WAY cheaper too.
Hats off btw.

[AJRFulton]

My question is..... what replacement pins for the clips should I purchase. I'm doing this from an oil rig, so can't just go out and look - but would like the stuff waiting on me for the 5 day window I have to do it.

The car has a bewildering variety of different connectors and as you know most have their own specific male/female pins. Afaik there is no generic female/male pin combo on the car.
The way I see it you have two options: Either go OEM connectors and pins or go generic electric/electronics connectors and pins. The latter is the most flexible by far as you will be making your own loom anyway. WAY cheaper too.
Hats off btw.

Would one of the generic packs from a well known online auction house be sufficient? with like 1000 pins of various sizes and shapes?

As said I don't actually want to make a loom - just I feel it is starting to cause issues - and given what I use the car for I anticipate having the engine in and out a few more times in the next couple of years - the issues are not going to get better.

One of the purposes of the car is to learn how to build a race car. I'm getting very close to having physically built, or removed and inspected every main component of this car. The steering column, brake pedal and windscreen wipers are the only moving parts I can think of that I haven't had off to replace, rebuild or inspect.

[AJRFulton]

double post

[Petrus]

I suppose it would be ámply sufficient. Have a look at the wiring schematics and count the connectors you will be replacing. Also a bag of pins never goes to waste. 

The only reason Toyota uses a multitude of different plugs is the fool-resistance; that only óne plug & socket will fit.
Making parts of the loom yourself you colour code the plugs and use your head.

Success!

[Alex Knight]

Now, correct me if I'm wrong, but could you just not remove your old engine loom, and replace it with a decent S/H loom from a breaker?

Repin the loom for a 2ZZ application, et voila?

Or is that too simple?

[AJRFulton]

Decent second loom is pricey, and potentially doesn't solve the problem. I've 3 looms lying there, plus another on the engine.

At least doing it from scratch I know it's all good.

[Alex Knight]

Decent second loom is pricey, and potentially doesn't solve the problem. I've 3 looms lying there, plus another on the engine.

At least doing it from scratch I know it's all good.

Well the price consideration is irrelevant if you have 3 additional looms.

I'd put one of those on then. Surely, surely it's waaaaay less work/time than making one from scratch.

[AJRFulton]

I have discovered (I think) the issue.

Wheel speed sensor. I damaged this whilst replacing a wheel bearing last year, but..... the ABS is removed from the car, and I never look at the speedo whilst driving on track (and besides - the car isn't road legal), so never bothered replacing it as it is something that isn't really needed (for the function it serves).

The speedo occasionally worked, as does the lift. I never usually notice when the speedo is working as I'm never looking at it, thus never put 2+2 together.

Apparently the OEM ECU needs a speed to engage lift - so I'm assuming the Apexi unit will be the same.

[Dev]

I have discovered (I think) the issue.

Wheel speed sensor. I damaged this whilst replacing a wheel bearing last year, but..... the ABS is removed from the car, and I never look at the speedo whilst driving on track (and besides - the car isn't road legal), so never bothered replacing it as it is something that isn't really needed (for the function it serves).

The speedo occasionally worked, as does the lift. I never usually notice when the speedo is working as I'm never looking at it, thus never put 2+2 together.

Apparently the OEM ECU needs a speed to engage lift - so I'm assuming the Apexi unit will be the same.

The oem ecu needs the car rolling at a minimum of 5mph otherwise the rev limiter is set lower. It is the same if the coolant temp is too low. This is to prevent the engine from damage.

If you use a Apexi power FC it doesn't have any of these safeties. You can free rev at idle to redline without any speed sensor  input.

[AJRFulton]

I have discovered (I think) the issue.

Wheel speed sensor. I damaged this whilst replacing a wheel bearing last year, but..... the ABS is removed from the car, and I never look at the speedo whilst driving on track (and besides - the car isn't road legal), so never bothered replacing it as it is something that isn't really needed (for the function it serves).

The speedo occasionally worked, as does the lift. I never usually notice when the speedo is working as I'm never looking at it, thus never put 2+2 together.

Apparently the OEM ECU needs a speed to engage lift - so I'm assuming the Apexi unit will be the same.

The oem ecu needs the car rolling at a minimum of 5mph otherwise the rev limiter is set lower. It is the same if the coolant temp is too low. This is to prevent the engine from damage.

If you use a Apexi power FC it doesn't have any of these safeties. You can free rev at idle to redline without any speed sensor  input.

Not sure that is correct.

The car will only rev to 7400 rpm at the moment, even on the rolling road - the engine is built to be capable of +9000 rpm and rev limit is set to 8400rpm - but it will not go above 7400rpm

Also lift will not engage with the Apexi until the engine is hot.

[Dev]

I have discovered (I think) the issue.

Wheel speed sensor. I damaged this whilst replacing a wheel bearing last year, but..... the ABS is removed from the car, and I never look at the speedo whilst driving on track (and besides - the car isn't road legal), so never bothered replacing it as it is something that isn't really needed (for the function it serves).

The speedo occasionally worked, as does the lift. I never usually notice when the speedo is working as I'm never looking at it, thus never put 2+2 together.

Apparently the OEM ECU needs a speed to engage lift - so I'm assuming the Apexi unit will be the same.

The oem ecu needs the car rolling at a minimum of 5mph otherwise the rev limiter is set lower. It is the same if the coolant temp is too low. This is to prevent the engine from damage.

If you use a Apexi power FC it doesn't have any of these safeties. You can free rev at idle to redline without any speed sensor  input.

Not sure that is correct.

The car will only rev to 7400 rpm at the moment, even on the rolling road - the engine is built to be capable of +9000 rpm and rev limit is set to 8400rpm - but it will not go above 7400rpm

Also lift will not engage with the Apexi until the engine is hot.

Ok I went ahead and did a little research and it appears from a post that I found that the power FC may have a RPM setting for limiters like idle and temp conditions however I don't remember seeing it, only a max limiter. If there is one it was not used with the various maps I had including the base map that comes with the power FC. It is possible that you have those parameters specified with your map if so maybe it can be turned off or modified.
 If you are running the power FC exclusively I would hook up the OEM ECU and see if any codes are present. This could point you to a bad sensor or component that needs to be rectified.