Rough cold running
Discussion
Catalysed or not ? If it is catalysed, the car could run fine when the ECU is in "Open loop" mode and start to struggle in "close loop" mode. Look at the lambda sensors and the harnesses.
Also look at the coolant temp sensor. When the engine is warm, if the sensor is faulty, the engine could be far to rich and start to struggle.
Also look at the coolant temp sensor. When the engine is warm, if the sensor is faulty, the engine could be far to rich and start to struggle.
Don't change anything.
You will need to check the TPS for it showing 0% at idle or 100% at idle regardless, as well as checking how smooth the TPS is across the full range (from idle to WOT) before/so as to condem it as failed (and to know which directional TPS you need to buy IF you need one).
Again, do check that the wiring (colours of the wires) have not been changed (about 3" away from the plug) because it is was a 'thing' with Ford selling the TPS with a plug, with a loom, with instructions how to correct the direction. A@
You might NEED to correct lots of other things, simply because the TPS is not directionally correct because the net knowledge it limited to the net and not real world TVR issues.
You will need to check the TPS for it showing 0% at idle or 100% at idle regardless, as well as checking how smooth the TPS is across the full range (from idle to WOT) before/so as to condem it as failed (and to know which directional TPS you need to buy IF you need one).
Again, do check that the wiring (colours of the wires) have not been changed (about 3" away from the plug) because it is was a 'thing' with Ford selling the TPS with a plug, with a loom, with instructions how to correct the direction. A@
You might NEED to correct lots of other things, simply because the TPS is not directionally correct because the net knowledge it limited to the net and not real world TVR issues.
Edited by Adrian@ on Monday 6th July 15:40
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
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
First thing - the engine WILL run with the TPS disconnected. It won’t run as well, but it will start and run. That’s not the reason for your breakdown.
Next - the fuel pump will run for 2 or 3 seconds after you switch ignition on, to pressurise the system, then will stop. Testing the fuel pump supply after those first few seconds will show “no supply”. Get your head down beside the near side rear wheelarch, you’ll see the pump. Get someone to switch ignition on. The pump should buzz, then stop. If it doesn’t, you need to check the pump with a direct supply wire, and/or check that the cars wiring does provide a supply.
If the pump is priming at all, then the system will pressurise, so when you remove a fuel pipe, there should be fuel spraying everywhere. If you’re getting no fuel when switching on and cranking, you should be looking at the pump and wiring first, not the TPS.
Just another thought - do the ignition and other warning lights come on before you start cranking?
Next - the fuel pump will run for 2 or 3 seconds after you switch ignition on, to pressurise the system, then will stop. Testing the fuel pump supply after those first few seconds will show “no supply”. Get your head down beside the near side rear wheelarch, you’ll see the pump. Get someone to switch ignition on. The pump should buzz, then stop. If it doesn’t, you need to check the pump with a direct supply wire, and/or check that the cars wiring does provide a supply.
If the pump is priming at all, then the system will pressurise, so when you remove a fuel pipe, there should be fuel spraying everywhere. If you’re getting no fuel when switching on and cranking, you should be looking at the pump and wiring first, not the TPS.
Just another thought - do the ignition and other warning lights come on before you start cranking?
Hi Andrew, then your page has the diagnostics stuff that is a good read...I only ever saw cars as last resorts, played with and then had to reset everything (mainly TVR additional vacuum pipes sucking themselves closed and TPS fitted incorrectly). A@
https://www.pistonheads.com/gassing/topic.asp?h=0&...
https://www.pistonheads.com/gassing/topic.asp?h=0&...
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