Feeling rich? One for the FI guys! |
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Feeling rich? One for the FI guys! |
Rod |
Sep 16 2019, 03:24 PM
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#1
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Senior Member Group: Members Posts: 616 Joined: 1-January 08 From: Farnham UK Member No.: 8,526 Region Association: England |
Hi all, it’s a FI diagnosis I’m after, please help.
1973 1.7L standard FI system. When hot after a long run, I have a really rubbish tick-over and car wants to stall. I thought it would be MPS as mine has already been opened by a PO, but it reads 94 ohms on the outer coils and 398ohms on the inner terminals. It seems to hold vacuum too (only tried sucking on it, don’t have a gauge) so can I rule that out?? I really want some further checks to do as it’s running so rich I can see smoke at a hot idle and it’s difficult getting it to pull away without bogging down (only when hot - it’s great when cold!!) So it’s a hot only problem I’m having. Thanks for any help. |
Rod |
Sep 17 2019, 03:52 PM
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#2
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Senior Member Group: Members Posts: 616 Joined: 1-January 08 From: Farnham UK Member No.: 8,526 Region Association: England |
Did you adjust the MPs for the proper AF ratios? If not, you need to. I have never had the MPS apart myself, it has screws on it rather than rivets though, so has been opened before obviously. I have no idea what settings it’s at. Go home. Substitute a known good MPS, try again. Report back. Ok, good shout. I hadn’t realised before last night that my MPS had previously been taken apart and rebuilt for some reason, the symptoms do point to this failing, So what with it being apart and me not knowing what’s been done internally I think it’s a good idea to change it. Jeff has one that he’ll rebuild this w/e so I’ll probably get that in to cross that off the list. Sounds like the CHT has a bad connection or is failing. Do you have an adjustable rheostat/variable resistor that you can plug inline to evaluate? Also, check your return line to be sure it isn't pinched/blocked. The latter will give you very poor gas milage. Ask me how I know this. (IMG:style_emoticons/default/headbang.gif) No, I don’t have a variable resistor or the patience to find one, fit it and investigate. For the money they are new from Porsche, I’ll get one and change it in any case. Have ordered this tonight... Which return line? And where are the kink points?? George, it's cool that you offer personal help. But this is a forum where thousands are here to help. We don't need to be sending people away from here to you. You can still help here. I agree The OP is knowledgeable and capable. Every one of these dialogues builds a larger base of enthusiasm and skill. Allow this process to run its course. This is not a vending opportunity. I appreciate both George’s post and yours.. I enjoy the diagnosis of such problems, so hopefully we’ll get there, plenty of George’s parts here already. What’s the best way to check fuel pressure? You guys refer to a harbour freight kit, but I’m in the UK.. been looking but can’t find a >30 gauge. |
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