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| Sluggish acceleration | Rate Topic |
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| Posted: 12-29-2014 12:41 am |
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1st Post |
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mcguan.2 Member
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So, I had 11609 under a cover for about a month due to all the rain in the Bay Area. When the weather finally broke, I was able to start it, but now the acceleration really struggles, like the carbs (dellortos) aren't getting enough fuel. When I go full throttle (and I mean only at full throttle), she sounds perfect, but anything less than that and it's gurgling, sputtering, and slight backfires. Also, if I'm starting from a stop, I have to rev up to get going or it sputters and stalls a bit before catching up, and continues to do that in every gear. Background info: I had a similar, but less pronounced problem about a year ago and it turned out that when I switched to the Dells, the fuel pump couldn't keep up with the demand of those carbs, so the new pump is only about a year old and was working fine before the layoff. Also, I pumped some gas out to see if somehow water had gotten into the fuel, but saw no water. I changed the fuel filter, but still have the issue. She used to start right up under full choke, but now that's a struggle, too.
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| Posted: 12-29-2014 08:57 am |
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2nd Post |
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UKJames Member
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Possibly one of your idle jets has got gunked up? That would explain why its fine at high RPM as they only work under 3000rpm Also check for oil in your distributor cap -Jim
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| Posted: 12-29-2014 02:03 pm |
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3rd Post |
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Brett Gibson JH5 20497 Member
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Pop the dizzy cap and look for dampness, with all the rain maybe some dampness/condensation got in and your not getting a good spark to the plugs.
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| Posted: 01-04-2015 10:40 pm |
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4th Post |
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mcguan.2 Member
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Thanks for the suggestions. It's really hard to actually *see* down in under the distrib cap, let alone actually get it off because of the location, but I was able to unclip one side and get some wd-40 in there and then blow it out. That seemed to help quite a bit, particularly from a dead stop. However, it still skips and hisses at constant acceleration and struggles mightily on the power side of things, like if I'm trying to get up a big hill in first, I have to hammer it down and can barely go into second before I crest the hill (keep in mind Bay Area hills). Finally, I don't know if I mentioned it, but starting is a real chore. Just getting the engine to turn over is really sluggish and sporadic. Starter was replaced last year, but it's not like a constant turnover like you'd expect, but more like what you'd get if the battery was almost dead (battery replaced last year also). Any other thoughts?
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| Posted: 01-04-2015 10:45 pm |
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5th Post |
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UKJames Member
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If the battery is good it sounds like you've possibly got a bad earth, may be worth checking the earth straps out? This could also be affecting your spark as well as the starter.
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| Posted: 01-05-2015 01:55 pm |
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6th Post |
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Brett Gibson JH5 20497 Member
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I'm thinking you need to start at the beginning and make sure that your ignition, timing, plugs, wires, compression etc are all correct before you touch the carb's, (that's the general rule of thumb).Sounds like you have a few systems that could be just simple things, once you have them correct (including the grounds) then look at the carb's, first and easiest would be to see if they are pulling the same air draw thru the barrels.
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| Posted: 01-17-2015 11:51 pm |
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7th Post |
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mcguan.2 Member
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I'm going to try and tackle checking the timing tomorrow, but having never done that before (on any vehicle) I'm open to tips. I've been reading about it online and read the shop manual, for finding the correct pulley marks. Reading the forum, it seems that with Dellortos I'm looking for 12 degree static timing? Also, in the interest of asking stupid questions, is the number one cyclinder the foremost on the engine? And, in looking at pictures on the forum, it seems that PO rotated the distrbutor 90 degrees. Anything that I should be weary of with that?
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| Posted: 02-28-2015 12:23 am |
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8th Post |
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mcguan.2 Member
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Brett Gibson JH5 20497 wrote:I'm thinking you need to start at the beginning and make sure that your ignition, timing, plugs, wires, compression etc are all correct before you touch the carb's, (that's the general rule of thumb).Sounds like you have a few systems that could be just simple things, once you have them correct (including the grounds) then look at the carb's, first and easiest would be to see if they are pulling the same air draw thru the barrels. Brett, I've gone through the ground straps, re-set the timing, checked the plug wires, and changed the plugs, and balanced the carbs (via curbtune). When I pulled the old plugs (see picture, plugs are in order 1-4 from left to right) the plugs on number 3 & 4 were extremely fouled, so would that indicate a problem with the rear carb (dellorto 40)? To review how this all came about and what the symptoms are that I'm having, the car was running great a couple months ago. Then we had about a month of rain and the car sat under the cover for the whole month. When the rain stopped and I went to take her out, the car spit and popped and struggled mightily through lower RPM range, and has since. At around 4000rpm, she comes to life and runs great. What's my next move? Attachment: SparkPlugs.jpg (Downloaded 85 times)
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| Posted: 02-28-2015 08:57 am |
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9th Post |
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UKJames Member
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I had a similar situation with my rear Dellortos having wet plugs. In the end I rebuilt the carbs, two of the pump jets weren't working, and the float levels were hopelessly different between the front and rear carb, with the rear carb overfuelling. It might be worth checking your floats / float levels initially and that the needle valve is operating.
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| Posted: 04-09-2015 06:02 pm |
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10th Post |
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mcguan.2 Member
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Thanks for the help, guys. I pulled the top off the rear carb to check the float level and when I was rocking it back and forth to find the point where the needle seated, it seemed really herky-jerky, so I replaced the needle valve. That more or less did the trick. I now have full, even acceleration. I'm still getting some hissing and popping at lower acceleration or when downshifting. Anything you'd recommend to look at for "fine tuning"? I'm pretty happy to have it back to near-normal but would like to get rid of those pops.
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