 Helping a friend with a 1976 FI that has intermittent low RPM stumble |
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| Tdskip |
 Jun 9 2021, 03:38 PM
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#1
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Advanced Member  Group: Members Posts: 3,686 Joined: 1-December 17 From: soCal Member No.: 21,666 Region Association: None 
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Hi folks-trying to help a friend out here that has a 1976 running its fuel in Jackson still and has a intermittent low RPM stumble where it feels like a cylinder or two or cutting out and then it recovers. I don’t have any set time with this injection system and I’m wondering if there’s a short list of weekly things to examine.
It only seems to happen at lower p.m., and I was able to invoke the issue by starting in second gear as a rolling start and almost flooring it, that seem to make it happen about every other time. Pulls cleanly once it recovers and always over 4000 RPM. Thanks! |
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Replies(1 - 3)
| rjames |
Jun 9 2021, 03:54 PM
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#2
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I'm made of metal Group: Members Posts: 3,948 Joined: 24-July 05 From: Shoreline, WA Member No.: 4,467 Region Association: Pacific Northwest
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Starting in second gear sounds like a sure fire way to lug the engine and I don't think would help you troubleshoot the issue.
There's the usual stuff you should do first- adjust the valves and verify the timing is correct. Assuming those are set correctly, it sounds like it's running a bit rich or lean- either one could cause a stumble off the line... or the distributor needs cleaning. Is it all stock? |
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| Tdskip |
Jun 9 2021, 04:22 PM
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#3
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Advanced Member Group: Members Posts: 3,686 Joined: 1-December 17 From: soCal Member No.: 21,666 Region Association: None
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Hi there, thanks for the response. I was only driving it like that to try to make the intermittent problem easier to identify and more readily invoked. Basically the idea is that if I can reproduce it on demand that’ll make troubleshooting it more straightforward.
I showed my friend where the grounds are underneath the relay board so he’s going to clean that up really well, will check for air leaks tomorrow.. I’ll make sure to ask him about when the valves were last adjusted etc.. I know that this is a interconnected system with lots of dependencies, just wasn’t sure if there was any “smoking gun” for those sorts of symptoms. |
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| Bleyseng |
Jun 10 2021, 07:42 AM
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#4
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Aircooled Baby! Group: Members Posts: 13,035 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
I’d first pull the distributor and clean and lube it.
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