Bogging while accelerating

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

Hi all.  I've been having a problem with my 1975 GTS 400 that has me at my wits end.  I am not mechanically inclined and use a mechanic who can't seem to find the solution to my issue. 

Basically what happens is this:  The car bogs down to the point of almost stalling when accellerating.  More so when it is cold, but even when it is warm to a certain extent.  It doesn't seem to do it every time on a complete straight stop (red light), but if I do a rolling stop and then accellerate, it almost always bogs.  If I am turning left or right and am rolling it will do it 100% of the time.

The car has been in my family since it was brand new, but it has basically been a garage sitter since the mid 80's.  I drove it for about a year in the mid 90's and it had the same problem then although it is definitely worse now.

Initially, I supected a problem with the old 2 bbl carb, so I've had it replaced with with a Holley 4bbl and Edelbrock IM.  Same problem exists with the new carb.

New plugs and wires of course.

New timing chain, new crankshaft bearings.  Engine runs better than it did when it was new, but still the same problem with bogging.

I've read on some other forums that it may be a problem with fuel tank venting or fuel lines.  Charcoal canister, or fuel pump.  The fuel pump was tested at idle, but not under load.

The car is in the shop again now, but I'd like to be a little more informed when I talk to the mechanic.  

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
Faker75GTS Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 13-October-2012 Location: Edmonton Status: Offline Points: 14	Post Options Post Reply Quote Faker75GTS Report Post Thanks(0) Quote Reply Topic: Bogging while accelerating Posted: 22-October-2012 at 6:58AM
	Hi all. I've been having a problem with my 1975 GTS 400 that has me at my wits end. I am not mechanically inclined and use a mechanic who can't seem to find the solution to my issue. Basically what happens is this: The car bogs down to the point of almost stalling when accellerating. More so when it is cold, but even when it is warm to a certain extent. It doesn't seem to do it every time on a complete straight stop (red light), but if I do a rolling stop and then accellerate, it almost always bogs. If I am turning left or right and am rolling it will do it 100% of the time. The car has been in my family since it was brand new, but it has basically been a garage sitter since the mid 80's. I drove it for about a year in the mid 90's and it had the same problem then although it is definitely worse now. Initially, I supected a problem with the old 2 bbl carb, so I've had it replaced with with a Holley 4bbl and Edelbrock IM. Same problem exists with the new carb. New plugs and wires of course. New timing chain, new crankshaft bearings. Engine runs better than it did when it was new, but still the same problem with bogging. I've read on some other forums that it may be a problem with fuel tank venting or fuel lines. Charcoal canister, or fuel pump. The fuel pump was tested at idle, but not under load. The car is in the shop again now, but I'd like to be a little more informed when I talk to the mechanic.

Faker75GTS Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 13-October-2012 Location: Edmonton Status: Offline Points: 14	Post Options Post Reply Quote Faker75GTS Report Post Thanks(0) Quote Reply Posted: 22-October-2012 at 7:25AM
	Also - Probably related .. the car absolutely reeks of gas in the garage. If it sits for about a week, the gas smell goes away, but start it up just once and your eyelids melt off.

unlovedford Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 17-December-2010 Location: Tennessee Status: Offline Points: 10150	Post Options Post Reply Quote unlovedford Report Post Thanks(0) Quote Reply Posted: 22-October-2012 at 8:13AM
	Tank venting, fuel pump, floats in the carb. I would check all of the lines, the fuel tank inlet, the gas cap, the fuel pump, and the carb floats. Sounds like a flat spot in the carb, but the cornering issue would seem to be realted to parts affected by non-level situations. Could be that gas is being sloshed around and the carb is running low on fuel pressure, etc. Does having a full tank help/hurt matters? Does the fuel cap hiss when opened after driving?
	Joe 1972 Mom's Squire Wagon 1972 Torino Wagon 1976 Torino 1968 Cougar XR7-First batch 1972 Torino 460 1989 BroncoII/Jeeps/Titanimous Popeye and Brutus (Rams)

Faker75GTS Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 13-October-2012 Location: Edmonton Status: Offline Points: 14	Post Options Post Reply Quote Faker75GTS Report Post Thanks(0) Quote Reply Posted: 22-October-2012 at 9:38AM
	It does seem to be worse when the tank is full. So hard to tell though since it does it virtually all the time. And yes, there is a slight hiss when the cap is removed normally. The problem hasn't changed one whit between the original 37 year old 2 bbl and the brand new 4 bbl. Hard to imagine that it is a carb issue because of that.

unlovedford Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 17-December-2010 Location: Tennessee Status: Offline Points: 10150	Post Options Post Reply Quote unlovedford Report Post Thanks(0) Quote Reply Posted: 22-October-2012 at 10:35AM
	Cheap start - see if the tank is vented and that venting system is functioning properly. If, by some chance it is not a vented tank, try a vented cap to relieve vaccume pressure. Have you checked your timing? Incorrect timing can disguise itself as a fuel problem. Check fuel lines for kinks in the rubber and metal lines, especially near the tank pickup. Check fuel pump pressure, and proper operation of the pump. Check vaccume lines on the engine for softness, kinks, etc.
	Joe 1972 Mom's Squire Wagon 1972 Torino Wagon 1976 Torino 1968 Cougar XR7-First batch 1972 Torino 460 1989 BroncoII/Jeeps/Titanimous Popeye and Brutus (Rams)

Faker75GTS Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 13-October-2012 Location: Edmonton Status: Offline Points: 14	Post Options Post Reply Quote Faker75GTS Report Post Thanks(0) Quote Reply Posted: 22-October-2012 at 11:25AM
	Timing has been checked. I believe it's at 12 right now. I've told the mechanic to drop the tank and trace everything to do with fuel delivery and venting. He had checked the fuel pump before, but not under load, so he is going to do that also. I'll talk to him about the vaccuum lines as well. The car has been sitting for almost 30 years (in a garage). It started up like a champ, but it definitely needs some TLC.

Mark S. Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 22-April-2012 Location: EHT, NJ Status: Offline Points: 374	Post Options Post Reply Quote Mark S. Report Post Thanks(0) Quote Reply Posted: 22-October-2012 at 11:42AM
	I would thoroughly check for a vacuum leak; maybe bad intake gaskets. Tank venting definitely an issue; I would get a new vented cap just to be sure.
	Mark 1977 Ltd II "Eltee" 1984 Mustang ragtop 2004 Grand Marquis Ultimate Edition 71 Torino GT 429CJ (sold too many years ago to count...)

Faker75GTS Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 13-October-2012 Location: Edmonton Status: Offline Points: 14	Post Options Post Reply Quote Faker75GTS Report Post Thanks(0) Quote Reply Posted: 29-October-2012 at 11:02AM
	Alright. The mechanic checked the tank, and the vent solenoid was seized. Also, some blockage in the line. New vent solenoid, line cleaned. Tank and pickup look clean, no rust at all. Problem is still there. He's saying that the float bowls aren't staying at the level they are set at. Car still bogs around corners. Any suggestions?

stanman Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23-March-2007 Location: Nova Scotia, Ca Status: Offline Points: 1434	Post Options Post Reply Quote stanman Report Post Thanks(0) Quote Reply Posted: 29-October-2012 at 11:14AM
	Carb may have picked up some dirt from the dirty line or the new filter may be plugged for the same reason.

Dan the ranchero man Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 24-July-2011 Location: Mchenry,IL Status: Offline Points: 1185	Post Options Post Reply Quote Dan the ranchero man Report Post Thanks(0) Quote Reply Posted: 29-October-2012 at 12:09PM
	Check the accelerator pump on the carb. The diapham could be shot. With the engine off open the butterflies and look into the carb, Pull the throttle back nice a steady and watch your fuel shot. It should be a nice stream (spray) coming out of the nozzle.

Robbdtme Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06-June-2012 Location: Central WI Status: Offline Points: 765	Post Options Post Reply Quote Robbdtme Report Post Thanks(0) Quote Reply Posted: 29-October-2012 at 6:54PM
	I would drain the gas tank and have a new so called "Fuel sock" filter put on it. You have a fuel feed issue. My mindless advice. had it happen to me before Looks like you have done this but if we do not see this with our eyes mechanics will charge and tell you the did it. You changed the carb give us more details
	Johnny cash Special 74-75-76 freak. 77 XR7. 78 LTD II sport looks pretty but poop 302 in it.

SininenIII Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 06-March-2008 Location: Vuolenkoski FIN Status: Offline Points: 462	Post Options Post Reply Quote SininenIII Report Post Thanks(0) Quote Reply Posted: 30-October-2012 at 1:08AM
	Fuel line not tight, sucks air while running?? My old fuel line had piece of rubber hose between hard lines, it had loose hose clamp and the engine sucked air, didn´t run well.
	Aatu 73 Gran Torino Sport

robot9000 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 02-September-2011 Location: Michigan Status: Offline Points: 506	Post Options Post Reply Quote robot9000 Report Post Thanks(0) Quote Reply Posted: 30-October-2012 at 4:15AM
	I'm betting its the carb. I'm guessing its the accelerator pump diaphragm that is leaking - hence the smell (gas leaking into the the throttle body) and the bogging (no gas to squirt/atomize in the chamber). Maybe get a rebuild kit and go over it. Especially since it sat for so many years. The components in the carb dry out and crack and such. If you had a problem with the fuel line or anything up to the carb, it would be a problem at high RPM, when gas is being pumped/sucked from the tank into the carb, but he only bogs on acceleration, which is usually a carb or timing problem. If there was a air leak or such, that would happen all the time at high RPM (high fuel load). It doesn't, only when he accelerates hard, which is what the accelerator pump on the carb is for.
	1973 Gran Torino Sport 2010 Mazda 6 2007 Jeep Wrangler 2011 Damon Daybreak 35BD

papadeath Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 08-December-2011 Location: Eagle Rock, CA Status: Offline Points: 498	Post Options Post Reply Quote papadeath Report Post Thanks(0) Quote Reply Posted: 09-November-2012 at 7:54PM
	Accelerator pump, float bowls. I'll bet 5 bucks it's one of those. Or both, hehe.
	75 Ranchero in progress 04 Harley Deuce stage one kit 89 Toyota pickup modded 09 Scion XB (bought for the ol' lady) buy American! (sorry) skateboard 4 bicycles 1 scooter 2 dogs 2 stupid cats

papadeath Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 08-December-2011 Location: Eagle Rock, CA Status: Offline Points: 498	Post Options Post Reply Quote papadeath Report Post Thanks(0) Quote Reply Posted: 09-November-2012 at 7:55PM
	Float bowls, duh, I meant floats.
	75 Ranchero in progress 04 Harley Deuce stage one kit 89 Toyota pickup modded 09 Scion XB (bought for the ol' lady) buy American! (sorry) skateboard 4 bicycles 1 scooter 2 dogs 2 stupid cats

Torinogts73c Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 14-February-2004 Location: Tucson Arizona Status: Offline Points: 1039	Post Options Post Reply Quote Torinogts73c Report Post Thanks(0) Quote Reply Posted: 13-November-2012 at 5:43AM
	I would be looking at the fuel level sender sock or filter in the tank. If that part closes because of the suction under load that would be your problem. New ones are readily available too!
	Gary 73 Gran Torino Sport 351CJ,17 Mustang Ecoboost,18 Lincoln MKZ Reserve, Ford Ranger parts hauler "Never complain Never explain" Henry Ford

papadeath Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 08-December-2011 Location: Eagle Rock, CA Status: Offline Points: 498	Post Options Post Reply Quote papadeath Report Post Thanks(0) Quote Reply Posted: 13-November-2012 at 7:00AM
	Yea, the original sock I replaced disintegrated into my fingers when I pulled it off. I put in a fresh, stiff one, hehe.
	75 Ranchero in progress 04 Harley Deuce stage one kit 89 Toyota pickup modded 09 Scion XB (bought for the ol' lady) buy American! (sorry) skateboard 4 bicycles 1 scooter 2 dogs 2 stupid cats