Lotus Elise S1 won't start.. fuel pump problem?
Discussion
Hi all i am from Sydney Australia and have a s1 elise, and am experiencing the same problem Fuel Pump not priming. It happened when i was stuck in traffic one hot sunny day and the car just stopped on me, after several attempts trying to start eventually got it towed to a garage, the mechanic showed me the fuel filter was full of dirt and looked brown, he has checked fuses and the multi function relay unit appears to be fine, he assumes tank would be filled with this dirty dead fuel thus causing the fuel pump not to work, also the fuel cut off switch seems to be removed i cant find the damn thing anywhere. so im guessing its the fuel pump itself, i was just curious every time it happens it happens on a real hot day, why is this? has it got do to with the fuel heating up..? the car getting hot? the car has not ever overheated, so buggered if i know
could be several things.
worth tracing the wiring back as the plugs on this can be problematic, the last thing to check is the pump itself, as this required the fuel tank to be removed from the car.
in order check:
1) inertia switch (Black thing bolted to the LH longeron close to the ECU)
2) then get somebody to turn the ign on whist you stick you head next to the MFRU and listen for the click of the fuel relay (what you waiting for is the click some 5 sec's after the ign as it turns the pump off).
3) the fuse
if all of these are OK, then it's probably the imob, they do this.
if you have a meter, then follow the power for the pump, it goes:
1) starter solenoid (Brown wire with black sleve on it)
2) fuse
3) Engine Harness connector 3 Pin 2
4) MFRU Big plug pin 4
5) MFRU Big plug Pin 1
6) Engine harness conector 1 Pin 4
7) Imob in
8) Imob out
9) Fuel tank harness connector
10) fuel pump
worth tracing the wiring back as the plugs on this can be problematic, the last thing to check is the pump itself, as this required the fuel tank to be removed from the car.
in order check:
1) inertia switch (Black thing bolted to the LH longeron close to the ECU)
2) then get somebody to turn the ign on whist you stick you head next to the MFRU and listen for the click of the fuel relay (what you waiting for is the click some 5 sec's after the ign as it turns the pump off).
3) the fuse
if all of these are OK, then it's probably the imob, they do this.
if you have a meter, then follow the power for the pump, it goes:
1) starter solenoid (Brown wire with black sleve on it)
2) fuse
3) Engine Harness connector 3 Pin 2
4) MFRU Big plug pin 4
5) MFRU Big plug Pin 1
6) Engine harness conector 1 Pin 4
7) Imob in
8) Imob out
9) Fuel tank harness connector
10) fuel pump
thanks for your reply scuffers, the mrfu is indeed making a click, i have checked the fuse in the back also is fine, i have also changed crankshaft sensor, so im hoping there is no power going to the fuel pump or the fuel pump itself. i forgot to mention that i poured a bit of fuel through the throttle body and it started for about 5 secs then turned off, wen i took the fuel filter off and try to crank it over there is no fuel coming out of the line, isnt it suppose to spit out fuel if your tryin to start it? as for the immobiliser ill be damned if i can find that, it is working fine regardless.
s1elisedriver said:
thanks for your reply scuffers, the mrfu is indeed making a click, i have checked the fuse in the back also is fine, i have also changed crankshaft sensor, so im hoping there is no power going to the fuel pump or the fuel pump itself. i forgot to mention that i poured a bit of fuel through the throttle body and it started for about 5 secs then turned off, wen i took the fuel filter off and try to crank it over there is no fuel coming out of the line, isnt it suppose to spit out fuel if your tryin to start it? as for the immobiliser ill be damned if i can find that, it is working fine regardless.
OK, if the MFRU is clicking then you have a wiring issue in the fuel pump cct.follow the list I posted above that's the order the power for the pump takes.
also, Just because the imob seems to work does not mean it does, they are not really designed to take the full current the pump draws and can fail, everything else works but no fuel pump.
Imob relaybox is behind a black plastic cover next to the ECU, it's connected by a whist multi-plug, all the wires are black.
you don't need to get at it, just follow the cct from the info above with a meter.
Hi, i had the same problem, tracked the fault down to a poor electrical connection on the fuel pump, looks like the factory didnt use any conductive / anti corrosive grease when they did the earth connections, as electrical resistance gets higher as the temperature increases the problem get worse the hotter the pump / electrical connections get. Its quite simple to fix - once you get the pump out which means you have to drop out the fuel tank, not too bad if you have a hoist.
Hope that helps.
Hope that helps.
s1elisedriver said:
Thanks scuffers..anyway I can bypass another connection? Where abouts are the earth connections located? Wen I unplug the immobilized nothing works
don't want to post up info on how to bypass the imob on a public forum.mail me you email addy and I'll mail you the detail.
hi scuffers, just read that you know how to by pass the imobiliser. Well mate im having a knightmare with mine on my s1 98 elise, ive had the AA out who said theres no power goin to the starter and fuel pump isnt switching on leading them to think my immobiliser is the problem, would really apreciate the instructions on how to by pass it if you can help scuffers?
Scuffers said:
s1elisedriver said:
Thanks scuffers..anyway I can bypass another connection? Where abouts are the earth connections located? Wen I unplug the immobilized nothing works
don't want to post up info on how to bypass the imob on a public forum.mail me you email addy and I'll mail you the detail.
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