172 Cup not running right

[Lazenby172]

Right, I was driving to work one day and suddenly i lost all power and car cut out, so pulled up and gave car a few mins then tried to start it and it was turning over but not firing unless i put a bit of revs on but even then it would just cut out and not idle.

So got AA out and diagnostic scanner pointed to throttle body so put a new one on and nothing changed so took to my uncles garage to which his scanner pointed to throttle position sensor so put a new one on.

Since then it now only starts when i turn key and put my foot on throttle until it fires and now it idles but struggles to hold idle. Also engine management light is on which it wasn’t before all this started.
Also fitted new plugs, leads and coil pack just to be sure.

Anyone got any ideas ?? Thanks

 

[STEVE.M]

Anyone got any ideas ?? Thanks

Any car in particular?

Diagnostic codes reveal which circuit is at fault, which includes the wiring!

A fault with the wiring is more probable than the hardware on Clio`s.?

 

[bloke]

Phase 1 I'm guessing then not a cup?

 

[Lazenby172]

Put diagnostic scanner on today and it says its MAP sensor now and it is a cup its a mk2 172 cup

 

[MonkeyKnifeFight]

Loose earth? Creates all kinds of inconstant electrical faults.

 

[R3k1355]

Sounds more like a wiring fault, you're going to need to go over the loom and check for breaks and loose connections.

The large white connector under the engine fusebox is a good place to start.

 

[STEVE.M]

Sounds more like a wiring fault, you're going to need to go over the loom and check for breaks and loose connections.

The large white connector under the engine fusebox is a good place to start.

The 90 pin connector on top of the ECU is more likely & easier to get to.

 

[bloke]

It doesn't have a tps, what did you replace then?

What was map reading at idle?

 

[R3k1355]

It doesn't have a tps, what did you replace then?

Probably the throttle pedal position sensor.

Usually when that error comes up it indicates a wiring fault/break somewhere on the loom, or occasionally the throttle body is gunked up.

 

[bloke]

Probably the throttle pedal position sensor.

Usually when that error comes up it indicates a wiring fault/break somewhere on the loom, or occasionally the throttle body is gunked up.

Tps is throttle position sensor.

 

[Lazenby172]

Tps is throttle position sensor.

It doesn’t have a throttle position sensor ??

 

[bloke]

It doesn’t have a throttle position sensor ??

nope, it's in with throttle body and pedal.

 

[Lazenby172]

nope, it's in with throttle body and pedal.

Yeah i changed the pedal and throttle body still no change

 

[STEVE.M]

Tps is throttle position sensor.

Are you sure?

Telephone Preference Service (TPS)

 

[R3k1355]

Yeah i changed the pedal and throttle body still no change

It'll be a wiring fault somewhere between the two, the 172 Cup is notorious for this problem.

Tps is throttle position sensor.

Yea but like you said it doesn't really have one to replace, and most people just lazily refer to the pedal sensor as the TPS.