Rough cold running

[123Larham]

My car starts fine but until it’s warmed up it pulls really rough a bit like kangaroo petrol or as if you are in the wrong gear approaching a junction or roundabout any idears where to look first thanks Mick

[123Larham]

Hi it’s the 2.9

[123Larham]

It’s the non cat model on the net some people say possible the TPS but I don’t want to change too many parts unnecessarily thanks Mick

[123Larham]

We’ll have just gone for a test run with the TPS unplugged to rule that out and now waiting for recovery I’ve taken one plug out and it’s bone dry and removed a fuel pipe near the distributor and when cranking the engine no fuel comes out there’s plenty in the tank however I can’t hear the fuel pump priming it’s self but it is on a noisy road so may be still working probably going to be a long night

[123Larham]

Well unfortunately I thought I was doing the right thing to test it as on the net it says remove it and it will run on a different map which is not ideal I’m not sure what to do now but as there’s no fuel coming through would the management system have shut this down? And would disconnecting the battery reset things ? Mick

[123Larham]

Hi both warning lights come on with the ignition but the fuel pump is not making any noise at all usually you can hear it just before you start the car so hopefully if I get home from work at a decent hour I will check to see if there is power at the pump thanks Mick

[123Larham]

Hi well there’s no power going to the fuel pump I’ve checked all the fuses and all are ok when I take the yellow relay out there’s constant power to pin 30 and switched live to pin 86 I have no way of checking the relay as I only have a basic power tester any idears please thanks Mick

[123Larham]

Just a thought is it possible to bypass the relay just to see if that’s the problem before I get a new one thanks Mick

[123Larham]

Right here’s today’s episode I’ve tested the relay with it plugged in and with the ignition on it has a healthy click and power to terminal 87 tested using a basic bulb type tester sadly the only thing I’ve got,testing at the pump end I get no light up at all so I have now hot wired the fuel pump to test that and all I get is a click but no spinning so I assume that’s dead but I’m not sure why the feed wires to it also show no joy any help please thanks Mick

[123Larham]

That makes sense so I assume that when I tried to hot wire the fuel the pump and it doesn’t pump it’s time for a new one and once it’s hopefully running again the feed will become live once running thanks Mick

[123Larham]

Thanks for your replies we have a family commitments from tomorrow after work till probably Sunday so will check it again and re earth it and go from there and I think the pump is at a reasonable price on TVRSSW spares fingers crossed that’s it thanks Mick

[123Larham]

The car has sat for quite a while before my ownership however the underside of the car looks pretty much like new so assuming it’s the fuel pump that has died I will replace the fuel filter at the same time there’s no telling how well the tank was cleaned out when it was recommissioned

[123Larham]

I ordered a new Bosch fuel pump which arrived today it took roughly 1 1/2 hours to fitt it then cycled the ignition a few times to prime the system again and hey presto it now starts again I’ve had no time today to go for a test run but will let you know how it goes and if the cold running is any different hopefully that could have been some of the problem if the pump was packing up Mick

[123Larham]

Had a few minutes to spare this evening when I got home from work so had a quick spin around the block when I first started the car it felt as though it had minimal throttle response but after all the pre flight checks were done I went with it and it seams ok but still a bit jumpy until fully warmed up a bit like you are in a gear too high and needing to down shift to gain a few revs and smoothness please bear in mind my previous car was a Scimitar GTE which wasn’t bothered what gear you was in it pulled smoothly from no revs at all Mick

[123Larham]

I’ve now got a top spec Chinese multimeter lol and have tested the TPS with it tonight the feed wire has 4.95v and the output wire has 0.56v at throttle closed and 4.02v at fully open as far as I could tell I don’t think there were any spikes how do these figures sound to you? Thanks Mick