chris956 Posted October 31, 2014 Share Posted October 31, 2014 R400 Duratec standard spec with throttle bodies ( caterham ). Running fine last time it was used and then today not so. Not changed anything other than charged the battery on a conditioner.Part throttle it dies then picks up , runs rough juddering all over the shop. Large throttle openings are fine and giving it 100% throttle clears the problem.I`ve checked plugs , coils , connections and air intakeAnything else I should look for ?? Link to comment Share on other sites More sharing options...
SM25T Posted October 31, 2014 Share Posted October 31, 2014 On my k-series it was the lambda sensor giving these symptoms. Unplugging it .... it ran fine. Bought a replacement on eBay from the number on the old unit. Sorted. Link to comment Share on other sites More sharing options...
Bio Posted October 31, 2014 Share Posted October 31, 2014 Could also be a defective TPS or cable going to it. Link to comment Share on other sites More sharing options...
chris956 Posted October 31, 2014 Author Share Posted October 31, 2014 Will check those 2 thanks Link to comment Share on other sites More sharing options...
Markiebabes Posted November 1, 2014 Share Posted November 1, 2014 Agree with Bio TPS cable is a known issue Link to comment Share on other sites More sharing options...
chris956 Posted November 1, 2014 Author Share Posted November 1, 2014 OK , checked the cable and no obvious tears , frays or chaffing. Cleaned the connector out with air gun. Noticed the other end of the cable disappears into the loom. Doesnt look disturbed ????? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 1, 2014 Member Share Posted November 1, 2014 Isn't there a functional test of the TPS that depends on disconnecting the sensor and seeing what happens? Have you checked the archives?Jonathan Link to comment Share on other sites More sharing options...
chris956 Posted November 1, 2014 Author Share Posted November 1, 2014 Checked the archives and all I could find was Adjusting the TB`s not the TPS sensor. Will unplug it to see what happens.... Link to comment Share on other sites More sharing options...
chris956 Posted November 1, 2014 Author Share Posted November 1, 2014 ...The engine stops immediately Link to comment Share on other sites More sharing options...
chris956 Posted November 1, 2014 Author Share Posted November 1, 2014 Just been out to test it and thought all was well whilst it warmed up but no chnace. As soon as it got to temp and I started to give it some stick the problem recurred. Its almost like someone switching it off for a second or 2 when you level out the throttle. Light thrpttle and WOT are no problem. Frustrating to say the least as it was fine last time out. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 1, 2014 Member Share Posted November 1, 2014 Is there a TPS sensor procedure for your model?What happens when it's warm and you disconnect the temperature sensor?Jonathan Link to comment Share on other sites More sharing options...
chris956 Posted November 1, 2014 Author Share Posted November 1, 2014 I`m not sure about the reset procedure - not that I have found at any rate. All the temp disconnect does at idle in the garage is make the fan come on , engine continues to run. The other temp sender ( to the gauge ) does nothing when disconnected other than make the gauge fall back to zero. Found a few articles on TPS and peoples problems. Sounds similar to mine but I have no way of checking the voltage etcso might have to leave it to an expert !! Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted November 1, 2014 Area Representative Share Posted November 1, 2014 Chris,Had this problem a few times in the first year after the build of my R400D. Could not decide if it was a miss fire or fuelling as a quick hard prod of the loud pedal cleared it but the problem would come back. Especially on trailing throttle. Suspected all the usual things: Fuelling (injectors), duff plug(s) or HT leads.After checking & confirming all these were OK I reverted to 'think simple/stupid' & disconnected every electrical connection under the bonnet to do with the HT & fuel system, including removing the ignition modules.Found a fair degree of light corrosion on most of the pins, especialy the ignition modules.Carefully scraped & cleaned all the connections, treated with contact fluid (not WD40 as this can attract back dust turning it into a hard deposit on electrical connections). Put it all back together. Car started first time & has run with no problems since that time (July this year). The only questions I had was how the engine must have been stored & for how long for this to happen. One does not expect this 'straight out of the box'. Link to comment Share on other sites More sharing options...
chris956 Posted November 1, 2014 Author Share Posted November 1, 2014 Thanks Geof. Your last sentance has it for me as the car was used last week with no problems ( and it wasnt even in the wet !). It is not a problem that has been getting slightly worse. I will however go over all the electrical connections again and look for corrosion... Link to comment Share on other sites More sharing options...
John Vine Posted November 1, 2014 Share Posted November 1, 2014 Have a really close look at the TPS wiring inside the connector. When my wiring fractured the first time (the brown wire IIRC), the actual break wasn't immediately apparent -- it turned out to be inside the connector itself (that is, behind the weather seals).If the wiring is OK, make sure the connector pins are scrupulously clean. As Geoff says, corrosion can be a problem.Also worth checking that the lambda wiring is intact and undamaged.JV Link to comment Share on other sites More sharing options...
F355GTS Posted November 1, 2014 Share Posted November 1, 2014 I assume the Duratec has a crank sensor if so it's worth checking, on VX's these would fail when they got hot and loose count of the teeth thus causing ignition/ injector timing to fail Link to comment Share on other sites More sharing options...
Bio Posted November 2, 2014 Share Posted November 2, 2014 Still sounds like a defective TPS, they can break down internally. Link to comment Share on other sites More sharing options...
chris956 Posted November 2, 2014 Author Share Posted November 2, 2014 Yep, could be. I have cleaned every connection today but the weather has been so bad I couldn't test the car. I have not attempted to dismantle or move the TPS. Looks simple enough but I don't have the diagnostic kit once its in bits. Link to comment Share on other sites More sharing options...
John Vine Posted November 3, 2014 Share Posted November 3, 2014 It certainly sounds like a TPS problem.IME, the Duratec installation in the 7 suffers unduly from high-frequency vibration, particularly apparent around the coils and induction. This in turn leads to fractured wiring and TPS damage. When I took my R400 to the Two Steves for mapping, Steve G commented that the TPS voltage he was measuring was all over the place. On inspection, it turned out that the TPS was falling to bits internally. A new one fixed the problem. AFAIK, the TPS isn't designed to be dismantled.You stated earlier that your TPS wiring "disappears into the loom". Presumably that means you don't have the upgraded silicone-sheathed sub-loom (which connects into the main loom via an Econoseal plug -- see http://s405.photobucket.com/user/trog65/media/TPS/CCTPSRacesubloomPart30L117A_zps1896d552.jpg.html). If your problem does turn out to be fractured TPS wiring, this upgraded loom is well worth considering. At £65-ish it's not cheap, but it does come with a (£40) TPS already connected. You'll have to add a connector for the main loom, of course.JV Link to comment Share on other sites More sharing options...
chris956 Posted November 4, 2014 Author Share Posted November 4, 2014 It certainly sounds like a TPS problem. IME, the Duratec installation in the 7 suffers unduly from high-frequency vibration, particularly apparent around the coils and induction. This in turn leads to fractured wiring and TPS damage. When I took my R400 to the Two Steves for mapping, Steve G commented that the TPS voltage he was measuring was all over the place. On inspection, it turned out that the TPS was falling to bits internally. A new one fixed the problem. AFAIK, the TPS isn't designed to be dismantled. You stated earlier that your TPS wiring "disappears into the loom". Presumably that means you don't have the upgraded silicone-sheathed sub-loom (which connects into the main loom via an Econoseal plug -- see http://s405.photobucket.com/user/trog65/media/TPS/CCTPSRacesubloomPart30L117A_zps1896d552.jpg.html). If your problem does turn out to be fractured TPS wiring, this upgraded loom is well worth considering. At £65-ish it's not cheap, but it does come with a (£40) TPS already connected. You'll have to add a connector for the main loom, of course. JVI have those spongy silicon leads on my coil packs but definately not on the TPS. Had another look yesterday. Still dont know if the problem is fixed after a connector clean up as had no chance to drive the thing. I`ll speak to Rob ( Boss ) when I see him this week all being well. Link to comment Share on other sites More sharing options...
chris956 Posted November 4, 2014 Author Share Posted November 4, 2014 It certainly sounds like a TPS problem. IME, the Duratec installation in the 7 suffers unduly from high-frequency vibration, particularly apparent around the coils and induction. This in turn leads to fractured wiring and TPS damage. When I took my R400 to the Two Steves for mapping, Steve G commented that the TPS voltage he was measuring was all over the place. On inspection, it turned out that the TPS was falling to bits internally. A new one fixed the problem. AFAIK, the TPS isn't designed to be dismantled. You stated earlier that your TPS wiring "disappears into the loom". Presumably that means you don't have the upgraded silicone-sheathed sub-loom (which connects into the main loom via an Econoseal plug -- see http://s405.photobucket.com/user/trog65/media/TPS/CCTPSRacesubloomPart30L117A_zps1896d552.jpg.html). If your problem does turn out to be fractured TPS wiring, this upgraded loom is well worth considering. At £65-ish it's not cheap, but it does come with a (£40) TPS already connected. You'll have to add a connector for the main loom, of course. JVI have those spongy silicon leads on my coil packs but definately not on the TPS. Had another look yesterday. Still dont know if the problem is fixed after a connector clean up as had no chance to drive the thing. I`ll speak to Rob ( Boss ) when I see him this week all being well. Link to comment Share on other sites More sharing options...
chris956 Posted November 5, 2014 Author Share Posted November 5, 2014 I am now in possession of :Ford Part Number 988F 9B989 BBwhich is the replacement TPS switch. Gonna fit it and try and get in exactly the same position as the existing fitted item as a test. Should the misfire be elliminated then it will be set with the plug in computer to the correct voltage.... Link to comment Share on other sites More sharing options...
chris956 Posted November 6, 2014 Author Share Posted November 6, 2014 Fitted the part and just been out for a quick blat. Back to its former glory. Because I`m a man I have taken the old one apart to see how rubbish it is inside and my god .. 2 bob job or what !! What a cr@p design.Anyway , thanks all for your help and encouragement. I have ordered a new one £17.99 for the spares box. I will in due course look at the uprated one with silicon wiring and swap to that. I did notice that the car took ages to get upto temp today due to it being generally cold outside. We used to tape up a quater of the radiator when we raced bikes to get them upto temp , do people do this on 7`s ? ? Link to comment Share on other sites More sharing options...
John Vine Posted November 6, 2014 Share Posted November 6, 2014 Delighted to hear that it's running well again. I'd agree that the TPS looks pretty cheaply constructed, but I suspect it's the inherent vibration that kills it. I've had several Mondeos over the years and never had a TPS problem with them.Note that CC's uprated TPS subloom has more durable and flexible wiring but the TPS itself is the same.Re covering part of the rad, I don't (although several do, I believe), but I do cover the oil cooler with kitchen foil.JV Link to comment Share on other sites More sharing options...
SM25T Posted November 6, 2014 Share Posted November 6, 2014 I blank off 1/3 or 2/3 of the nosecone with black closed cell foam between the 7 grille and mesh at this time of year. Link to comment Share on other sites More sharing options...
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