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I'm lost...hesitation issue...bad acc pump symptoms??
#1210679
04/05/12 11:38 PM
04/05/12 11:38 PM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
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OP
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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Not too long ago, I swapped a 360 cam into my 318. I always had a SLIGHT hesitation/flatspot right off idle, but its more noticeable now that the truck is running "right" -I set the initial timing at 12 before -Stripped the carb and cleared/cleaned every orifice and passageway I could. Put back together with new gaskets -new accel coil -new firecore plug wires -new "brain box"/stock replacement -newer distributor -new dist cap -new rotor cap -newer plugs (maybe 10k miles) -dont know fuel pressure, but verified flow -new fuel filter -just flushed gas tank -replaced vacuum line to distributor vacuum advance -have the a/f screws set to 2 out (carter 2 bbl) -Running 91 octane -3 speed A745 Firing order IS correct. Once she revs past that spot, she will  but it is that initial step on the gas that I always wince, because she wants to stall. What am I missing? I was thinking accelerator pump, but can't justify the $20 to "guess" and HOPE that was the problem... Sometimes she starts first hit of the key in the AM, and sometimes I have to crank like hell, while pumping like hell to get her to start. Could the fuel pump be "just good enough" to pump gas, but leak down/back to the tank over night, or even have low pressure at low RPM..maybe a bad valve in the fuel pump?? Someone PLEASE help point me in ANY direction  
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210680
04/06/12 12:18 AM
04/06/12 12:18 AM
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Joined: Nov 2011
Posts: 2,154
Its a TRAP!
DARTH V8Я
Oh No!! I just had a moron attack!
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Oh No!! I just had a moron attack!
Joined: Nov 2011
Posts: 2,154
Its a TRAP!
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210682
04/06/12 12:55 AM
04/06/12 12:55 AM
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Joined: Jul 2011
Posts: 817
Eugene, Oregon
Secret Chimp
super stock
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super stock
Joined: Jul 2011
Posts: 817
Eugene, Oregon
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Take the air cleaner off after running it (so you know the bowl is 100% full) and look down the barrels while you push the throttle lever back. Whether or not the accel pump is working should be pretty obvious. Pay close attention to what it's doing at the beginning of its travel.
If it is working, have you actually tuned your idle mixture based on RPM or vacuum? Two turns out could be completely off for your engine if you haven't checked anything beyond the number of turns you made initially.
1967 Dodge Coronet Deluxe station wagon
1.03" T-bars, QA1 arms/rods, Cordoba/GM Metric/Volare brake & knuckle, XHDs, Hellwig rear sway, 318 Magnum w/ air gap, 727, 3.23s
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210684
04/06/12 01:03 AM
04/06/12 01:03 AM
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Joined: Feb 2003
Posts: 1,637
Florida
GMP440
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Florida
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Are you running spark ported vacuum or manifold vacuum?. If you're, as a result you will get hesitation or a flat spot. running manifold vacuum to the distributer vacuum advance , you will lose some of your vacuum advance when you stab on the pedal.
You may want to check fuel pressure at the carb.
I would also check the the curb idle mixture with the car in gear. It could be lean in this area. You may not have enough carburetion for the cam you're using.
Another thing to check with the carb off is the butterfly in relation to the off idle slot. If it's below the slot you will get some flat spot on acceleration.
Last edited by GMP440; 04/06/12 01:05 AM.
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: Secret Chimp]
#1210685
04/06/12 01:17 AM
04/06/12 01:17 AM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
top fuel
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OP
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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Quote:
Take the air cleaner off after running it (so you know the bowl is 100% full) and look down the barrels while you push the throttle lever back. Whether or not the accel pump is working should be pretty obvious. Pay close attention to what it's doing at the beginning of its travel.
If it is working, have you actually tuned your idle mixture based on RPM or vacuum? Two turns out could be completely off for your engine if you haven't checked anything beyond the number of turns you made initially.
OK...with the air cleaner off, and engine warm (after running) when I push the throttle slowly, it dribbles out for the first split second, then squirts almost enough to hit the other side...
all adjustments are based on RPM. I havent had the pleasure of doing it by vacuum YET. I'm not sure what kind of gauge I need anyway...just a regular vacuum gauge??
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: GMP440]
#1210686
04/06/12 01:22 AM
04/06/12 01:22 AM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
top fuel
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OP
top fuel
Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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Quote:
Are you running spark ported vacuum or manifold vacuum?. If you're, as a result you will get hesitation or a flat spot. running manifold vacuum to the distributer vacuum advance , you will lose some of your vacuum advance when you stab on the pedal.
You may want to check fuel pressure at the carb.
I would also check the the curb idle mixture with the car in gear. It could be lean in this area. You may not have enough carburetion for the cam you're using.
Another thing to check with the carb off is the butterfly in relation to the off idle slot. If it's below the slot you will get some flat spot on acceleration.
That was going to be another question of mine...Where do I hook the vacuum line from the distributor to? Right now it goes from the vacuum advance, to the back of the carb. Is that the right spot? the only other spot for a vacuum line, is where the line to the air cleaner goes.
I havent switched yet to see if it makes a difference 
where its hooked up now, it has vacuum at idle
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210688
04/06/12 02:35 AM
04/06/12 02:35 AM
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Joined: Jul 2011
Posts: 817
Eugene, Oregon
Secret Chimp
super stock
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super stock
Joined: Jul 2011
Posts: 817
Eugene, Oregon
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Depending on your carb, sometimes you can fix the "initial dribble" problem by adjusting the pump rod so the pump starts off further down in the bore. It may even be out of spec with respect to that adjustment, or your float level may be too low. But it should be easy enough to measure where your pump is sitting at right now (in case you need to change it back) and bend the rod so it sits another few millimeters further down at rest.
1967 Dodge Coronet Deluxe station wagon
1.03" T-bars, QA1 arms/rods, Cordoba/GM Metric/Volare brake & knuckle, XHDs, Hellwig rear sway, 318 Magnum w/ air gap, 727, 3.23s
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: GMP440]
#1210689
04/06/12 02:47 AM
04/06/12 02:47 AM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
top fuel
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OP
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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Quote:
You mentioned that you checked accelerator pump operation and noticed the pump shot dribbles first and then gives you a good pump shot stream. Should just be a solid pump shot stream.
ok..going to get the new accelerator pump in the morning, and swap for peace of mind..
Quote:
Also, go ahead and switch the vacuum line to the other port. Should be the spark ported vacuum port. To verify this just put your finger on the port to see if you have vacuum at idle. If no vacuum at idle , that's the one.
where it is hooked now, there is a lot of vacuum. Enough so, that when I put my finger over the tip of the hose, the hose stick to my finger
Quote:
Also with a vacuum guage, check to see what the vacuum readings are when you rev up the engine. This will also check that you are getting a vacuum rise at precisely the same time as you blip the throttle lever. If you are that's good; if it's delayed then just increase the idle speed to allow the throttle blades to be just at the base of the idle slot so at the time the slots are uncovered you will get vacuum to the vacuum advance instantaneously. If you find the idle speed too high you can back it down by lowering the timing. 12 degrees advanced maybe too much; you can back it down to about 1 or 2 degrees BTDC or just have it straight up at 0 degrees top center. Another way of lowering the idle speed too is to enrichen the idle mixture.
at TDC, she backfires when I attempt to give her gas. At 12 BTDC, the screws out 2 turns, and the idle adjustment screw adjusted, I have a VERY healthy idle ~750 - 800 RPM.
Cruising down the highway it is OK, same with idle..at idle it is ok, but taking off it is a pain, unless I high rev it (~2000 RPM) then let the clutch out SLOWLY
I'm going to do what you reccomended in the morning, and I hope I'm done before work lol 
Thanks for the leads 
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: Secret Chimp]
#1210690
04/06/12 02:53 AM
04/06/12 02:53 AM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
top fuel
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OP
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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Quote:
Depending on your carb, sometimes you can fix the "initial dribble" problem by adjusting the pump rod so the pump starts off further down in the bore. It may even be out of spec with respect to that adjustment, or your float level may be too low. But it should be easy enough to measure where your pump is sitting at right now (in case you need to change it back) and bend the rod so it sits another few millimeters further down at rest.
yeah, there were two slots the rod could have gone in. it HAD been in the inner slot(closest to carb) but since I changed it to the outer slot, I havent noticed any change. I could try to bend the rod to make it shorter. The float was set to whatever the instructions said to set it to. IIRC, level with the bowl, or am I thinking the ford carb again All I remember is setting it to what the piece of paper in the kit said 
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210691
04/06/12 03:08 AM
04/06/12 03:08 AM
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Joined: Jan 2003
Posts: 1,999
s. e. pa.
calrobb2000
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Joined: Jan 2003
Posts: 1,999
s. e. pa.
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hi do yourself a favor and get a 4 bbl intake an carb. best thing i ever did to my 318 van ws install a performer intake with a 600 holley electric choke ! it also had the 360 cam !  8-12 deg timing should be fine with stock dist .
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: calrobb2000]
#1210692
04/06/12 03:21 AM
04/06/12 03:21 AM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
top fuel
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OP
top fuel
Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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Quote:
hi
do yourself a favor and get a 4 bbl intake an carb.
best thing i ever did to my 318 van ws install a performer intake with a 600 holley electric choke !
it also had the 360 cam !
8-12 deg timing should be fine with stock dist .
Don't laugh. I have a complete top end from a 360 including a 4bbl intake I've been resisting the urge to swap onto this 318. I just don't know what condition the valves are in. I am SERIOUSLY tempted since I have that brand new Qjet itchin to be used 
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210693
04/06/12 03:40 AM
04/06/12 03:40 AM
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Joined: Jan 2003
Posts: 1,999
s. e. pa.
calrobb2000
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Joined: Jan 2003
Posts: 1,999
s. e. pa.
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hi what heads do you have now ? you dont want to lower your compression . a pair of 302 heads with mild port bowel work would be good ! too large a valve and port and combustion chamber will make a truck a slug ,that cam does not want to big a ports on a smaller engine !
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210695
04/06/12 11:30 AM
04/06/12 11:30 AM
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Joined: Jan 2003
Posts: 75,012
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,012
U.S.S.A.
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Quote:
where it is hooked now, there is a lot of vacuum. Enough so, that when I put my finger over the tip of the hose, the hose stick to my finger
Do you have a timing light ? If so hook it up and look at your idle timing with the vac line disconnected , then connect it up , if the timing move you either have the wrong port or your throttle is open to far uncovering the transfer slots .
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: magnum440d100]
#1210697
04/06/12 02:58 PM
04/06/12 02:58 PM
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Joined: Jul 2011
Posts: 817
Eugene, Oregon
Secret Chimp
super stock
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super stock
Joined: Jul 2011
Posts: 817
Eugene, Oregon
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Quote:
Quote:
hi
do yourself a favor and get a 4 bbl intake an carb.
best thing i ever did to my 318 van ws install a performer intake with a 600 holley electric choke !
it also had the 360 cam !
8-12 deg timing should be fine with stock dist .
Don't laugh. I have a complete top end from a 360 including a 4bbl intake I've been resisting the urge to swap onto this 318. I just don't know what condition the valves are in. I am SERIOUSLY tempted since I have that brand new Qjet itchin to be used
Pft valves schmalves, I put a 4 barrel on my 105,000 mile 1967 motor (valve stem end heights were all even) and it just rips shiznit now. Throw that BBD or whatever out the window and have fun :P
1967 Dodge Coronet Deluxe station wagon
1.03" T-bars, QA1 arms/rods, Cordoba/GM Metric/Volare brake & knuckle, XHDs, Hellwig rear sway, 318 Magnum w/ air gap, 727, 3.23s
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Re: I'm lost...hesitation issue...bad acc pump symptoms??
[Re: Secret Chimp]
#1210698
04/06/12 07:28 PM
04/06/12 07:28 PM
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
magnum440d100
OP
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OP
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Joined: Jan 2010
Posts: 1,944
woodcrest, CA
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ok, an update..missed work, but thats fine since the machine shop called and said my 360 was ready for pick up... had to wait for the accelerator pump to come in, but once it came in, I rushed down there and got it. I put it in, and now there is a steadier shot of gas. I think it could be better, but its better than it WAS. Switched hoses on vacuum ports on the carb. no noticeable difference. REtimed to 10 before TDC...still no HUGE difference. Shifts are WAY smoother, and surge is gone, but that flat spot upon take off is still there. Its a LITTLE more tolerable though.. I'm going to tweak the accelerator pump rod a bit to see if I can make it better... OR I can just swap to the 4bbl intake, run the almost brand new Qjet, and call it done ASSuming the Qjet can be adjusted to run better than this 2 bbl
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