reamer Posted July 29, 2019 Share Posted July 29, 2019 I usually don't drive on the highway, but the car show was 28 miles away, Soooooo, on the highway flat road holding 75mph, up hill losing speed, down shifting to 4th, still losing speed, Step on it and boy the growling noise under the hood IS impressive but still losing speed, What the H***! Regular street driving seems fine, but again stepping on it, Great "toilet flushing" noise, but no increase in speed! Yet and a stop sign, it will chirp from a dead stop, (rules out clutch) So, back in the bat-cave I investigate.... 4 year old Edelbrock 1406? Non EGR 4-v and intake. No visual leaks stains. 15 inches vacuum, 10 BTC (with vac advance plugged) Pulled all the plugs, while all out, did a compression test, 145 to 150 psi throughout. Installed new Autolite plugs, gapped to 44. Thought the rubber fuel line might have been collapsing, Sooo bent up a new 1/4" brake line. 6 psi of pressure on 4 year old mechanical fuel pump. Head down the road, just as crappy as before, 40 mph and step on it, lots of deep growling but no increase, actually decrease in speed.... Just for fun, swapped out modules, same result. Thoughts? Link to comment Share on other sites More sharing options...
Rembrant Posted July 30, 2019 Share Posted July 30, 2019 You didn't mention the fuel filter...I assume you changed it? What about the fuel tank and sending unit? Have they been replaced?...Maybe the "sock" on the sender is plugged up? I know, I'm not much help... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 30, 2019 Share Posted July 30, 2019 Lack of volume, not pressure? Something amiss with the secondaries? Links, interlocks, hanging butterflies??? Link to comment Share on other sites More sharing options...
reamer Posted July 30, 2019 Author Share Posted July 30, 2019 Lack of volume, not pressure? Something amiss with the secondaries? Links, interlocks, hanging butterflies??? Yes new inline filter too, My Brother mentioned going to a 3/8" (minimum) ID fuel line but the original line from the tank is only 1/4" and the fuel pump won't take 3/8" Tank and pick-up are @6 years old.... Link to comment Share on other sites More sharing options...
grumpin Posted July 30, 2019 Share Posted July 30, 2019 Lack of volume, not pressure? Something amiss with the secondaries? Links, interlocks, hanging butterflies??? I’m still suspicious of the clutch. Or an intake leak. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 30, 2019 Share Posted July 30, 2019 I’m still suspicious of the clutch. Or an intake leak. Intake leak would have been my guess, but he doesn't mention any other symptom like high idle. Slipping clutch would show on the tach. EGR leak would sound that way at cruise, but he said it just gets louder if he floors it. Clogged catalytic converter fits the symptoms. Is there anything left of the A.I.R. thermactor system left on this truck? 3/8 feed and 5/16 return seem standard on any Ford I've ever seen. 1/4" is a -4AN hose, 3/8 = -6AN, etc... I'm having a hard time finding flow rates for 1/4" at any pressure, let alone 6 psig. Link to comment Share on other sites More sharing options...
reamer Posted July 30, 2019 Author Share Posted July 30, 2019 Intake leak would have been my guess, but he doesn't mention any other symptom like high idle. Slipping clutch would show on the tach. EGR leak would sound that way at cruise, but he said it just gets louder if he floors it. Clogged catalytic converter fits the symptoms. Is there anything left of the A.I.R. thermactor system left on this truck? 3/8 feed and 5/16 return seem standard on any Ford I've ever seen. 1/4" is a -4AN hose, 3/8 = -6AN, etc... I'm having a hard time finding flow rates for 1/4" at any pressure, let alone 6 psig. Idles at 600 650, nothing left to the emissions, Eddy intake is a non-EGR, ran great for a few years, Three years ago did the ZF swap new hydraulics, slave , master, clutch. Idles fine. Tach. is steady, no jumping.... Still a clean top end no oil or coolant leaks..... Don't remember if it still has a catalytic converter.... will have to look Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 30, 2019 Share Posted July 30, 2019 Idles at 600 650, nothing left to the emissions, Eddy intake is a non-EGR, ran great for a few years, Three years ago did the ZF swap new hydraulics, slave , master, clutch. Idles fine. Tach. is steady, no jumping.... Still a clean top end no oil or coolant leaks..... Don't remember if it still has a catalytic converter.... will have to look I would definitely give a look for a clogged exhaust. You have all the symptoms. Just for giggles, unbolt the front of the muffler (or Cat if you have one) and take it for a spin. 15" Hg is pointing at a clog too. Stock should have 20+, and it takes a pretty healthy cam to put you at 15. Link to comment Share on other sites More sharing options...
reamer Posted July 30, 2019 Author Share Posted July 30, 2019 I would definitely give a look for a clogged exhaust. You have all the symptoms. Just for giggles, unbolt the front of the muffler (or Cat if you have one) and take it for a spin. 15" Hg is pointing at a clog too. Stock should have 20+, and it takes a pretty healthy cam to put you at 15. Well did more testing, At idle (600 ish is smooth) look down the carb no dripping at idle.. did the Cat "snap" test, says that snap to WOT, vacuum should drop only for a second and recover almost instantly (if not clogged) and it does this. Did second Cat test, Hold at 2500 rpm, if vacuum steadily drops over time, its clogged, this comes right back to 15 and over time looks to be increasing to 16 inches. Runs great standing still... Timed to 10 BTDC, (with vac advance hose plugged) but wondering if timing goes out the window, with an acceleration load.... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 30, 2019 Share Posted July 30, 2019 Well did more testing, At idle (600 ish is smooth) look down the carb no dripping at idle.. did the Cat "snap" test, says that snap to WOT, vacuum should drop only for a second and recover almost instantly (if not clogged) and it does this. Did second Cat test, Hold at 2500 rpm, if vacuum steadily drops over time, its clogged, this comes right back to 15 and over time looks to be increasing to 16 inches. Runs great standing still... Timed to 10 BTDC, (with vac advance hose plugged) but wondering if timing goes out the window, with an acceleration load.... Standing still,. but not under load. That's why I said secondaries.... Link to comment Share on other sites More sharing options...
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