The Rich List..

[gizzardio]

Hi All

After trawling best I could on here using the less than perfect search facilities I've compiled what I think are the symptoms for suspecting rich running/overfuelling issues in my V8S.

1) Strong smell of petrol around esp when cold
2) Stalled recently when cold and wouldn’t restart for a while – suspect flooded engine
3) Big rise in fuel consumption – was about 250miles per tank, now about 180-200
4) MOT test shows HC figure 560 when 2 previous years show 150 which I believe is an indicator of unburnt fuel in exhaust. CO2 was fine.
5) Rough /lumpy idling when warm or cold and feeling like its going to die when throttle opened when cold
6) Jumpy / kangarooing when pulling away from cold start up. Sensation as if I had over sensitive throttle.
7) Pops and bangs through exhaust now a lot more frequent and noticable.

I'm after a list of things to check in order of difficulty, cost and equipment before I send it in to the professionals. Does anyone have anything to add or change to this below?

ECU coolant temp sensor - short this out and see if anything changes or just replace.
Throttle potentiometer - disconnect and run?
Lack of spark(s) / weak spark(s) - inline spark tester or arc to block?
Injectors jammed open - test with bulb across each one?
Fuel Rail pressure - need a garage for this one i think
AFM - wouldnt know how to test this tho?
ECU itself (ECU mate req'd?)

Oil & filter change & brand new B7ECS plugs about 200miles ago gapped to 0.9mm.

thanks for any help.

Edited by gizzardio on Tuesday 10th July 17:43

[Dave_M]

Sorry I have no idea about technichal stuff, but my (and others) tank went within the last two years so it may be worth checking it isn't leaking.

[gifdy]

I may be too far away from you, but I've got a box of bits that could be used for swap out testing. Includes AFM, fuel regulator, HT leads, dizzy, two different ECUs, fault code reader, etc, etc. Available on loan basis to any V8Sers in the area.

[gizzardio]

Dave - I will check this as sometimes the simplest explanations are right.

gifdy - yep its a shame I live too far for that journey. All the spare kit sounds perfect for what I am doing. do you have a link to a coolant temp sensor I need? - been told its in £12-£15 range so seems a cheap and easy trial first off.

[gifdy]

That's one component that's pretty easy to check. Stick it in a pan of water with a thermometer and measure the resistance with a multimeter.

>>>

The Coolant Temperature Sensor should change resistance with heat, per the following specs.
10C (14°F) 9100-9300 Ohms
0C (32°F) 5700-5900 Ohms
20C (68°F) 2400-2600 Ohms
40C (104°F) 1100-1300 Ohms
60C (140°F) 500-700 Ohms
80C (176°F) 300-400 Ohms
100C (212°F) 150-200 Ohms

If not, I think this is it (although not the cheapest) :

http://www.racetechdirect.co.uk/tvr-car-parts-deta...

Edited by gifdy on Tuesday 10th July 14:19

[v8s4me]

You’re looking in all the right places and your problems could be a combination of a number of things. Based on personal experience, I’d suggest before spending a lot of money, check the wiring to the ECU and look for dodgy connections on the tune resistor and faulty permanent live feed to the ECU. Steve Heath’s fault code reader or his new piece of kit will be a good investment. Also check the seating of the stepper motor; if the washer is too thick it can cause some of the problems you describe.

Once you’ve ruled out all the wiring/sender/ECU connections plus the usual plugs, coil, HT leads etc, again based on personal experience, get hold of Mark Adams and get him to fit one of his Tornado chips and then set it all up for you on a rolling road. This can be horribly expensive due to the costs of hiring the RR so get as much sorted out before you go to see Mark. Mine took just under two hours and three runs to get it perfect. But many, many, many hours of cursing, head scratching and help from here prior to the RR session to get all the other problems identified and sorted. He also does something to the plenum butterfly which makes pick up much better.

Notice I use the word “problem” as opposed to “issue” which is management Boocks. Issues are for discussion, problems need sorting!!

[gizzardio]

Cheers chaps. So you would agree with my assumption that it is over fueling then.

I can see it might be a tricky one cos the solution might not be immediate and obvious each time something is changed or checked. I'll work down the list best I can tho. Hearing about these ECU mate devices, having one would help to see what the signals from various sensors reporting ant the ECU iteself are. I'll look into it.