Fuel pump initial operation

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Wrightpayne
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David,

Anyone local who could loan one? They are EU2 / EU3 specific. EU2 has the distributor on the rear of the head.

Ian

revilla
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An EU2 MFRU YWB10022 will work in either an EU2 or EU3 loom. An EU3 MFRU YWB100970 will only work in an EU3 loom, it won't work in an EU2 loom. It requires an extra 12V feed to the fuel pump relay, so the symptom would be that the fuel pump wouldn't run ... which would really confuse the ssue in this case!

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm

revilla
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If you need an EU3 one to try I can stick one in the post. But do you have a multimeter? If so, can talk you through some simple diagnostic checks.

SV VVC 170 - 170.4 bhp @ 7100 rpm - 142.4 ft.lb. @ 4900 rpm

Fridybrydy
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Evening all. Thanks for the responses. It sounds like mine will be a EU2 as my distributor is on the back of the head. I’ve had to knock the fault diagnosis on the head for the rest of the bank holiday. Will let you know how I get on when I resume the fault finding.

Piers300
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I too have an R300 with EU2. I had a starting problem that took 2 and a half years to find. It’s a long read on here in the archives (A Reluctant Starter) but the problem turned out to be a bad earth on the ECU. It would crank but not fire as the injectors were not working. The multi pin socket under the throttle bodies was also corroded and cleaning that with contact cleaner helped. It’s not easy to get apart by the way. I also have a spare MFRU that I could lend you if in East Kent. I changed that thinking it was the problem.

Fridybrydy
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Evening all,

Thanks very much for raft of info and offer of assistance. I had another go at the car this morning/afternoon and managed to get her fired up. I'll give you the story from start and hopefully finish of the problem.

Initial problem, Laserline immobiliser disarmed with touch fob and ignition switched on. On pressing the starter button only a click from the MFRU. (Didn't know much about the MFRU in the begining). A local lad from the West Yorkshire and Pennines group kindly gave me a hand and he bypassed the immobiliser. The car then started. He then replaced the immobiliser the following week and the car started.

Next morning, Laserline immobiliser disarmed with touch fob and ignition switched on. Initial run of the fuel pump was not heard, the car would crank but not fire. Placed a spark plug against the block while turning her over an had a really strong spark. With the plug being dry on removal I assumed no fuel was being pumped (Also not hearing the initial run of the fuel pump). Being we had disturbed the wiring up behind the dash in the area near the fuse block, I assumed we may have disturbed some wiring there. Having received some wiring drawings kindly linked from Jonathan Kay I investigated further.

During my investigation I have found the following issues. Badly made connection where a 12v cigarette socket had been previously been spliced in causing the 12v to the brown/slate wire at the MFRU large connector to fail. (Removed 12v cigarette socket wiring and re-made original wiring). Bad connection at engine loom to main loom connector causing high resistance/intermittent continuity. (Re-wired to bypass connector.) Loss of continuity between the main loom connector and the fuel pump fuse in the cockpit. (Unable to find the cause of this, so re-wired from green/yellow wire coming out off MFRU large connector through an inline 10 amp fuse and onto the yellow/green wire into the inertia switch.) Bad connection between the large MFRU connector and the MFRU itself. Resolved using electrical contact cleaner. Several times after curing each of the issues she would start fooling me I had cured the problem only to fail again at a later date. Now I feel reasonably confident she'll start everytime. I am aware however, that the use of contact cleaner to fix the last issue is still a little disconcerting. The only way to more confidently fix this issue is pull the yellow/green wire out of the MFRU large connector and fit a new female termination and I don't have a tool for this. The male connector as part of the MFRU looks ok

MOT in the morning. Thanks again for your assistance. Kind regards David

SM25T
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Great news. Well done. Ian
Wrightpayne
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The crimped joint on the green / yellow wire inside the loom tape is still something I'd look at. On my car its within a couple of inches of where the cable for the inertia switch exits the main loom. It would be <5mins to unpeel the tape and check.

Ian 

7 wonders of th...
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The standard looms sadly have many opportunities for crap joints just waiting to let you down..... 

Fridybrydy
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Hi Ian, looked back in the loom as you suggested for inline crimp but it doesn't exist on my car. Thanks for your suggestion. Car is running fine now. Thanks David.