June 7, 201113 yr comment_358032 To be clear, did you still experience a 3000 RPM rev-limit with the TPS unplugged? If you didn't, that *IS* the source of your rev limiting problem. You then would need to verify the TPS is working properly and adjust it correctly. Edited June 7, 201113 yr by FastWoman Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358032 Share on other sites More sharing options...
June 8, 201113 yr Author comment_358092 the original problem wasn't so much a "rev limit" it was just more of a not wanting to give any more power because it was running too rich. Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358092 Share on other sites More sharing options...
June 8, 201113 yr Author comment_358093 sometimes when i first start the car it will seem fine and accelerate great for a few seconds then the problem will kick in again. Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358093 Share on other sites More sharing options...
June 8, 201113 yr comment_358094 When you first start the car, it's running very rich. Then it gradually leans out as it warms up. You're almost definitely running too lean, rather than too rich. That can give you incomplete combustion and the black, sooty plugs and exhaust that go with it. That can also give you backfire through the intake, as the burn takes a very long time and can extend through the next intake cycle. To verify that you REALLY DON'T have any intake leaks, try my yogurt cup test. For some reason nobody wants to do it, but one guy on this list would have saved an ENORMOUS amount of diagnostic time if he had simply followed this advice. If it helps you to do it, consider it a "beer can test," although I don't know whether a beer can is really the right size to plug the intake. You'll need one cup of Yotastic yogurt -- any flavor you like. Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358094 Share on other sites More sharing options...
June 8, 201113 yr comment_358099 See, I told you, can you take a caliper reading on the yogurt cup so I can find the proper beer can? Fastwoman, I will try you're test soon (for another reason), Brento there is no way anyone here can diagnose youre engine trouble, that is why people give different test suggestions, I would listen to both cozye and fastwoman test you're vacuum and you're fuel pressure then continue from there but try the simple things first I have noticed that the efi system on my 77 needs little adjustment but it does need maintenance does this make sense? Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358099 Share on other sites More sharing options...
June 8, 201113 yr comment_358104 fwiw, if it's popping through the intake as you suggested earlier, it's running lean, not rich. Pull the plugs and post a pic of them and that should confirm it. Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358104 Share on other sites More sharing options...
June 8, 201113 yr comment_358106 and if you haven't done so already, order this http://www.summitracing.com/parts/SUM-800160/SuggestedParts/?prefilter=1 and a 3/8 inch T fitting listed in the accessories. Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358106 Share on other sites More sharing options...
June 8, 201113 yr comment_358111 and if you haven't done so already, order this http://www.summitracing.com/parts/SUM-800160/SuggestedParts/?prefilter=1 and a 3/8 inch T fitting listed in the accessories.or it sounds like a good excuse for me to take a sunny road/boat trip with my Moto Guzzi, girlfriend (Her Ducati) and my fuel gauge to the San Juans!!! Or WTF my car is a 77 also I could race her there, then go scuba diving. Sorry got summer time on my mind. Edited June 8, 201113 yr by grantf spelling Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358111 Share on other sites More sharing options...
June 8, 201113 yr comment_358134 or it sounds like a good excuse for me to take a sunny road/boat trip with my Moto Guzzi, girlfriend (Her Ducati) and my fuel gauge to the San Juans!!! Or WTF my car is a 77 also I could race her there, then go scuba diving. Sorry got summer time on my mind.I must admit, I am a bit jealous of the great riding you west coast guys have. That's a great excuse! Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358134 Share on other sites More sharing options...
June 8, 201113 yr comment_358140 Yeah, road trip! Grantf, the yogurt cup is tapered, so it fits like a sink stopper. I don't really know/remember where on the yogurt cup taper the thing fits, so I don't know if a beer can would also fit. I guess I'd have to try it. Unfortunately we buy our beer (and softdrinks) in bottles, so I'd actually have to go out and buy a canned beer for that! Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358140 Share on other sites More sharing options...
June 8, 201113 yr Author comment_358167 horay for the yogurt test. fixed an air leak (injector to intake).so pay day ill order a fuel pressure gauge. im havin a buddy's step dad who was a z machanic come over this weekend.hopefully that will sort out my $^!#.i really appriciate the help. this is the most helpful forum ive ever been on Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358167 Share on other sites More sharing options...
June 8, 201113 yr comment_358168 Yay! Glad it helped you! Link to comment https://www.classiczcars.com/forums/topic/39785-77-280-acceleration-problem/?&page=2#findComment-358168 Share on other sites More sharing options...
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