wanted Injector or temp plug and socket

[TVRleigh]

Ok I've made a twin pot Gauge tester.
Small one is fine tuning 1ohm to 1k and the other goes to 5k



I just need to get a plug and socket for it the same as goes on the injectors / temp sensor.

Then it can be used also as a sensor by-pass.

[jmorgan]

any help?

[GreenV8S]

This is to fool the ECU? Not sure why you'd want to do that, but if you do you might as well put a fixed resistance corresponding to the temperature you want to pretend the engine is at?

[TVRleigh]

Well I want it varible so I can also use it to test gauges also.

Would only use to confuse the ECU. to test tick over problems. also with it being varible you can test the ECU.

That why i put a fine and wide adjuster, so you can just use the fine one to make sure you don't adjust it too much.

[GreenV8S]

TVRleigh said:

Well I want it varible so I can also use it to test gauges also.

Would only use to confuse the ECU. to test tick over problems. also with it being varible you can test the ECU.

That why i put a fine and wide adjuster, so you can just use the fine one to make sure you don't adjust it too much.

The sender used for the gauges is separate to the ECU one, has different resistance characteristics and doesn't use the same type of connector.

If you suspect the ECU's coolant temp sender is lying, it's trivial to measure the resistance and check whether it's correct. The only thing this test rig seems to achieve is to let you fool the ECU, but so far I don't see why you'd ever want to do that. I can't think of any diagnostic value.

[TVRleigh]

I know they have different resistance, the setup has enough range to work for both the ECU and gauge. only thought it would be handy if the sender did fail, at least I could fake the sender to get me home.

I did a chart in a previous thread, showing all the resistance values for all 3 senders.

I did not know though that the conectors are different, they look the same at 1st glance. well the cold start and ECU senders, I know the sender for the gauge is different, but will have a 2nd set of wire for that.

[shpub]

If the sender fails, the ECU uses a standard default value. Disconnecting it will do the same BTW. Most failures are the wrong values so that the ECU detects a valid temp but it is not the same as the real temp and the mapping goes out. Only way to find that is to measure the temp sensor in situ. I have had senders that work fine out of the engine but fail in situ.

[GreenV8S]

TVRleigh said:

only thought it would be handy if the sender did fail, at least I could fake the sender to get me home.

A failed sender is most unlikely to stop you getting home, but if it *did* cause trouble you could simply disconnect it. If you wanted to persuade the ECU to work normally despite the duff sensor you could just connect a fixed 300Ohm resister after the engine has come up to temperature. It's no skin off my nose, but I don't see what you're expecting to achieve.

[adam quantrill]

It might be handy for the MOT - set it up with the resistance you need to get a pass ;^)

It would also be useful to check the correct operation of the ECU over the whole sender range. What if the ECU had a dodgy mapping internally - you might only ever see it briefly at a certain temperature. Whether you could fix it or not is another matter....

BTW in that link is it the "4145 2 pole female housing" that we need? I could do with a few of these if you want to split the order - 10 off is a bit much!

Edited by adam quantrill on Friday 31st August 11:11

[dickymint]

Isn't there a "snakeoil" gizmo around that does just that?

[TVRleigh]

GreenV8S said:

TVRleigh said:

only thought it would be handy if the sender did fail, at least I could fake the sender to get me home.

A failed sender is most unlikely to stop you getting home, but if it *did* cause trouble you could simply disconnect it. If you wanted to persuade the ECU to work normally despite the duff sensor you could just connect a fixed 300Ohm resister after the engine has come up to temperature. It's no skin off my nose, but I don't see what you're expecting to achieve.

I just wanted a multi purpous board with multi conectors that could be used to test / bypass any sensor or gauge.

I will put a plug and socket on it. the socket will used so you can connect the meter to the PCB test points and not have to try and get the meter into the top of the socket, esp as they keep falling off.

I'll also put a spade conectors on to test the temp, oil pressure and fuel gauge's

Im not trying to do anything special, just want to compare what the gauge say and compare to the real figure. so just thought I'd make somthing a bit more multi-pourpose.

[TVRleigh]

Hi Adam, they do singles also. or is there a big price break for 10.

adam quantrill said:

BTW in that link is it the "4145 2 pole female housing" that we need? I could do with a few of these if you want to split the order - 10 off is a bit much!

[dwgriffith]

Go down to a breakers yard and grab as many as you like already terminated off jags, rovers, fords, just about any 90's model will do.

[adam quantrill]

Yeah but - they tend to be a bit corroded and whatnot, the plastic is getting brittle, if I were fitting another I'd deffo use new terminals and probably new housing.

[GreenV8S]

They're so cheap new, it's false economy trying to reuse knackered old ones. Last thing you need if this is intended as a diagnostic aid is to end up chasing faults in your test equipment.

[Wedg1e]

I used a (?)2K (or maybe 5K) linear response pot. (as opposed to logarithmic) in my injection tester and still found that the range of valid resistances that would allow the car to run properly were in a VERY small arc of the pot travel.