henry21p Posted January 9, 2006 Share Posted January 9, 2006 OK - new fuel pump fitted and tested using direct 12v feed Voltage at plug that goes to fuel pump also tested - getting voltage on turning the key for a few seconds (giving fuel pressure) and then also when cranking (as expected). Connect the two up - no pump initialisation. The above tests have eliminated fuse/relay and immobiliser problems as well as a break in the circuit (including from the inertia switch). So - the problem appears to be that UNDER LOAD, i'm not getting enough power to the pump (my tests on the voltage are on the disconnected plug). My head hurts. Edited by - dave21p on 15 Jan 2006 12:59:21 Link to comment Share on other sites More sharing options...
Big Brother Posted January 9, 2006 Share Posted January 9, 2006 Just a thought..... Is there a problem with the ground for the pump? How does it ground? through the main connector? If so, try running the ground directly to the chassis and see if there is any difference. Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
henry21p Posted January 9, 2006 Author Share Posted January 9, 2006 good thinking batman. will test that and see Link to comment Share on other sites More sharing options...
Mike Bees Posted January 9, 2006 Share Posted January 9, 2006 Have you removed the black plastic connector from the pump itself? I made the mistake of doing this - when I reconnected it then unbeknown to me it pushed the part of the connector which is in the pump (white plastic/nylon bit) into the tank and so wasn't making contact. Ended up in the same situation as you - voltage at the end of the loom where it connects to the pump, but no pump action. Mike Link to comment Share on other sites More sharing options...
henry21p Posted January 9, 2006 Author Share Posted January 9, 2006 checked all of that... new pump and pump operates properly when given direct feed. I think my pump is different from a 7 pump anyway - but thatnks for the idea. Link to comment Share on other sites More sharing options...
neil.cavanagh Posted January 9, 2006 Share Posted January 9, 2006 did you try putting an ammeter in the circuit when cranking (with pump connected) to see if what current is being drawn? OR could you put the volt-meter across the terminal of the pump with it plugged in and running. If there is some fault in the circuit that is causing a high resistance elsewhere then you won't see the full 12v droppping over the pump when all plugged in and trying to crank (the volts will be dropped across the 'fault' in the circuit rather than the pump). You could then practise your ohms law (v=ir) and figure out how big the resistance in the circuit is! 😬 Link to comment Share on other sites More sharing options...
henry21p Posted January 9, 2006 Author Share Posted January 9, 2006 not yet - it rained on me before i got a chance.... and is difficult to get in to put things in series in the circuit without hacking it about and if i'm doing that I might as well just replace it with known good parts! Link to comment Share on other sites More sharing options...
henry21p Posted January 11, 2006 Author Share Posted January 11, 2006 any more ideas of things to test/check before we hit the weekend? Link to comment Share on other sites More sharing options...
Myles Posted January 11, 2006 Share Posted January 11, 2006 Where are you this w/e? I've got to check out a banger for my sister on Saturday ( Damn, that'll not pass the PD test... ) but if you happen to be in Meriden... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
henry21p Posted January 11, 2006 Author Share Posted January 11, 2006 unfortunately 2 problems 1 - moved out of meriden to elsewhere in cov 2 - car is daaarn sarf - but if you still want to help i can offer beer/food/sunday lunches etc. (p.s. that offer isn't just for Myles - anyone who can help get me road worthy is welcome - Trev's volunteered at the moment but he might get sidelined helping someone remove a diff) Link to comment Share on other sites More sharing options...
Myles Posted January 11, 2006 Share Posted January 11, 2006 I suspect I can't easily make it this w/e - have you got tools down there btw? Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
henry21p Posted January 11, 2006 Author Share Posted January 11, 2006 yes. apart from a jack got to fix engine mount too. Link to comment Share on other sites More sharing options...
Myles Posted January 11, 2006 Share Posted January 11, 2006 That'll be tricky without a jack... Whereabouts is this btw? Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
henry21p Posted January 11, 2006 Author Share Posted January 11, 2006 south - about 2 hrs from yours. drop me aline via email and i'll give you address/directions Link to comment Share on other sites More sharing options...
Myles Posted January 11, 2006 Share Posted January 11, 2006 Blatmail is working again... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
julians Posted January 11, 2006 Share Posted January 11, 2006 I very recently had exactly the same problem. I had voltage on the wire at the pump, but the pump itself didnt work. I eventually traced it to a corroded live wire in the little resin block on the outside of the pump housing. It was no longer connected to the terminal where it enters the pump. Edited by - julians on 11 Jan 2006 14:56:38 Link to comment Share on other sites More sharing options...
henry21p Posted January 11, 2006 Author Share Posted January 11, 2006 but surely a replacement pump would have fixed that? or maybe i'm getting the same error, but before the pump i can get pump to run on 12v direct supply. Link to comment Share on other sites More sharing options...
julians Posted January 11, 2006 Share Posted January 11, 2006 Maybe we're talking about different pumps. The one on the 7 consists of 2 parts, the pump itself and the metal housing that holds the pump and allows the whole assembly to bolt to the fuel tank. the wires went into the metal housing and it was here that they had corroded. Replacing the pump itself made no difference. I guess if your entire pump assembly works when connected to a 12v supply then its not the same problem as mine. Link to comment Share on other sites More sharing options...
henry21p Posted January 11, 2006 Author Share Posted January 11, 2006 The 21 uses a pump assembly that has pump and fuel gauge that drops into the top of the tank and screws down (behind passenger head) Link to comment Share on other sites More sharing options...
henry21p Posted January 15, 2006 Author Share Posted January 15, 2006 traced back all the wires and found the problem One of the wires going from the back of the relay unit had a very slight split in it where it had been bent at an angle (right in the middle of a tight bunch of wires) - only reason we spotted it was the mess left by the resultant corrosion of the core in the wire. Really tiny tiny little problem! Link to comment Share on other sites More sharing options...
Normans_Ghost Posted January 15, 2006 Share Posted January 15, 2006 dave, you should have saved yourself a lot of time and aggro and got it on a diagnostic machine. They usualy pin point corroded connections. Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here You and your seven to The French Blatting Company Limited Link to comment Share on other sites More sharing options...
henry21p Posted January 15, 2006 Author Share Posted January 15, 2006 no diagnostic port unfortunately norm... and the car wasn't working so couldn't get it anywhere. but you're right in theory ;-) Link to comment Share on other sites More sharing options...
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