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View Full Version : edelbrock install, very hard starting when warm **UPDATE**


Jayrodoh
07-28-2005, 01:55 PM
Got the new engine in and running, holy crap the edelbrock intake/cam/carb makes a difference! It starts fine cold but is very hard to start warm. Acts like its flooded. Anyone else with this?

[ July 30, 2005, 12:32 PM: Message edited by: Jayrodoh ]

Bob Barry
07-28-2005, 02:21 PM
I've been having the same problem with the warm weather, but only when it's been sitting for a while. Very puzzling, as it was fine in the cold, and holding the throttle to the floor doesn't help, like it would if it was flooded.

It takes a LOT of cranking, and then slowly it might begin to catch, and eventually run. Almost like the bowl has run dry. Also sometimes a problem starting in the morning.

But if it's within an hour or so of shutting down, I don't even have to touch the gas and it starts on the first turn.

I have noticed that it's worse when the truck is parked pointing uphill.

Fiddling with the position of the choke-plate makes no difference.It seems like it's squirting gas, but not very much, from the accelerator pump.

I too would like an answer; this is my first AFB-design carb.

Jayrodoh
07-28-2005, 02:34 PM
That's weird Bob, you'd think it'd be the other way around. Mine is fine if it sits. I'll let you know if I figure anything out. Gonna play with it more Saturday.

supercopjason
07-28-2005, 02:50 PM
check the choke. Try taping the connectors on the choke and see if that works. Try adjusting the carb more. I bought my truck for 400 because this problem and i just adjusted the carb and POW! it ran.

endothermicbiped
07-28-2005, 02:54 PM
Mine does the same thing (Edelbrock carb & intake). But then again...it was doing the same thing with the stock intake (although still with the Edelbrock carb). I always called that symptoms of a vapor lock. My CJ did the same thing after I put intake and carb (a Holley in that case) on it. I fixed it by putting a spacer under the carb and mounting an electric fuel pump down on the frame rail up under the skid plate. Now it cranks like a champ hot or cold. I haven't had my J10 for long but I suspect doing the same will remedy the problem. FWIW...on the J10 I just got done putting a heat shield under the carb and wrapping the headers. That eased the problem a little bit but it still doesn't fire right up like the CJ.

Kevin718
07-28-2005, 03:51 PM
I am also having a similar problem:
91 GW, stock intake and carb, insulating carb spacer is installed, stock mechanical fuel pump

Symptoms:
- Difficult to start on hot days after the engine has been run awhile.
- Sounds like it is flooded.
- Takes longer to start if I accidentally touch the gas pedal.
- Have not tried to start with the pedal all the way to the floor to help purge the excess fuel. I will need to try that.

Why does this happen?
- I am thinking the heat is boiling the fuel and pushing it through the carb to the intake. Is this correct?
- I also thought that the carb bowl vent solenoid was suppose to open when the engine is off so that the charcoal canister could recover the excess vapor from the carb bowl. If so, then that might be my problem. But I have read recent posts indicating that it is suppose to be open during engine operation and closed when the engine is off. Does anyone know which is correct?

Thanks for bringing this topic up.

Dmntxn77
07-28-2005, 03:59 PM
This seems like a common problem. It is weird that I dont remember seeing it addressed before...

Best of luck to all of you. I will have to stay posted on this one because I plan on getting an Edelbrock intake soon..

scantar
07-28-2005, 04:00 PM
Originally posted by Kevin718:
But I have read recent posts indicating that it is suppose to be open during engine operation and closed when the engine is off. Does anyone know which is correct?

Thanks for bringing this topic up.I'm pretty sure that when it's running the vent is closed and when it;s off the vent is open to allow vapors out of the carb. I've been having similar problems with my 87 and I'm thinking the solenoid isn't opening the vent. At least that's my story and I'm sticking to it.....for now.

Steve

Kevin718
07-28-2005, 04:21 PM
Steve,

I think I agree with you. From the wiring diagram, I know that the carb bowl vent solenoid is receiving power when the ignition is in the run position. Now all I need to do is pull some vacuum on one side and see when it will hold the vacuum and when it will vent. Or find out if it does not move anymore.

So many Wag projects, so little time.

mechanical man
07-28-2005, 11:29 PM
I have the Eldebrock Performer with a Holley 600 cfm on my 360 and it starts instantly when cold and in about 3 turns when hot with the gas pedal about 1/2 way down. I am still running a stock fuel pump and the motor has headers on it. It gets real hot under the hood but I have never experienced vapor lock. I have a paper gasket under the carb that might be 1/8" thick so no insulation there. If you guys are having flooding problems, holding the throttle plate open during a hot start should help. Typically engines don't have flooding problems when hot-the gas evaporates so well the plugs don't get wet. I would look hard at the ability of the ignition system to put out a good spark when cranking when hot.

xsonmyeyes
07-28-2005, 11:36 PM
Mine's doing the same thing but it was doing it with the stock carb & intake too. I just hooked up the electric choke so we'll see if that helps. It starts right up when it's on a cold start but if I shut it down to get gas or go to the store...crank, crank, crank then it finally hits. Wonder what's up??

xadamant
07-29-2005, 12:03 AM
I was runnning into the same problem and had to adjust the choke, set the timimg, adjust the carb about three times over before getting the right combination.

Jayrodoh
07-29-2005, 12:18 AM
Originally posted by mechanical man:
I have the Eldebrock Performer with a Holley 600 cfm on my 360 and it starts instantly when cold and in about 3 turns when hot with the gas pedal about 1/2 way down. I am still running a stock fuel pump and the motor has headers on it. It gets real hot under the hood but I have never experienced vapor lock. I have a paper gasket under the carb that might be 1/8" thick so no insulation there. If you guys are having flooding problems, holding the throttle plate open during a hot start should help. Typically engines don't have flooding problems when hot-the gas evaporates so well the plugs don't get wet. I would look hard at the ability of the ignition system to put out a good spark when cranking when hot.That's exactly how I start mine. Mabye this is just normal for that carb, kinda sucks though.

J4GRAND
07-29-2005, 02:19 AM
Make sure with the Edelbrock that you have some sort of spacer in addition to the gasket between the carb and the intake to combat "boil off" of fuel from the float bowl. The procedure mechanical man describes is what I do too. A lot of times, I barely put any pressure on the pedal when the engine is warm.

uglyjeepling
07-29-2005, 04:14 AM
My float bowl would really dry up quick on the AFB. It would take some cranking to fill it enough to get some gas to the pump(with mech pump). In the summer I only pumped the gas 1/4, anymore was to much and I would have to let it sit for a few. Any less wouldnt give it enough to start. In the cold one pump to the floor to set the choke and it starts. Much easier to mash and go. smile.gif Since I got the elec. pump I turn on the key and it fill it up no matter the time it sat so there is a lot less cranking. I think the bowls dry up fast and boil off fast in these AFB's. They have pretty large vents and not much thermal diversion from the fuel. We all might just have to put up with it on these babies.

Jayrodoh
07-29-2005, 04:51 AM
Originally posted by uglyjeepling:
My float bowl would really dry up quick on the AFB. It would take some cranking to fill it enough to get some gas to the pump(with mech pump). In the summer I only pumped the gas 1/4, anymore was to much and I would have to let it sit for a few. Any less wouldnt give it enough to start. In the cold one pump to the floor to set the choke and it starts. Much easier to mash and go. smile.gif Since I got the elec. pump I turn on the key and it fill it up no matter the time it sat so there is a lot less cranking. I think the bowls dry up fast and boil off fast in these AFB's. They have pretty large vents and not much thermal diversion from the fuel. We all might just have to put up with it on these babies.You'd think if the gas boiled out when it was hot, it's be hard to start cold too until the gas flowed back up in.

scantar
07-29-2005, 04:53 AM
Originally posted by scantar:
</font><blockquote>quote:</font><hr />Originally posted by Kevin718:
But I have read recent posts indicating that it is suppose to be open during engine operation and closed when the engine is off. Does anyone know which is correct?

Thanks for bringing this topic up.I'm pretty sure that when it's running the vent is closed and when it;s off the vent is open to allow vapors out of the carb. I've been having similar problems with my 87 and I'm thinking the solenoid isn't opening the vent. At least that's my story and I'm sticking to it.....for now.

Steve</font>[/QUOTE]I should also add that I'm having this problem with 1 of my 2 GW's, both with stock 2150 carbs. The 1 that's giving me trouble is a "little old lady" PO truck and it sat for most of the last 3 years before I rescued it smile.gif The 1 that's not giving me problems is my dd beast with 240K on it...which keeps me thinking it's a solenoid issue. The carb is sparkly clean inside and out.

Steve

yipcanjo
07-29-2005, 05:48 AM
You guys *REALLY* aren't making me want to install the new Carter 625 carb that I just got! ;)

Bob Davis '80 Chero
07-29-2005, 05:57 AM
I've heard it's hard to start warm when the timing is off. Might want to check the timing and see if that helps. Mine is hard to start cold, but it sits for a week (or more) at a time.

uglyjeepling
07-29-2005, 07:06 AM
Originally posted by Jayrodoh:
</font><blockquote>quote:</font><hr />Originally posted by uglyjeepling:
My float bowl would really dry up quick on the AFB. It would take some cranking to fill it enough to get some gas to the pump(with mech pump). In the summer I only pumped the gas 1/4, anymore was to much and I would have to let it sit for a few. Any less wouldnt give it enough to start. In the cold one pump to the floor to set the choke and it starts. Much easier to mash and go. smile.gif Since I got the elec. pump I turn on the key and it fill it up no matter the time it sat so there is a lot less cranking. I think the bowls dry up fast and boil off fast in these AFB's. They have pretty large vents and not much thermal diversion from the fuel. We all might just have to put up with it on these babies.You'd think if the gas boiled out when it was hot, it's be hard to start cold too until the gas flowed back up in.</font>[/QUOTE]Your right and I think it is unless you have a insulator block which helped a ton. Doesn't lose as much gas to boil after you park it so the bowls stay fuller and takes longer to dry up when it sits. But to help your problem I think we are talking different things.

[ July 29, 2005, 01:09 PM: Message edited by: uglyjeepling ]

jeepguzzi
07-29-2005, 02:07 PM
For the first time, I experienced vapor lock while on vacation last week. The next morning it wouldn't start. I was parked slightly uphill and it acted like it was flooded. Temps were in the mid 90's to over 100 all week. Lots of humidity, too.

One other thing that I noticed was that I would get a vapor lock at about 130 to 140miles after filling the gas tank. I vented the tank by loosening the gas cap a bit. It would vent ALOT of pressure.

So, does anyone have a part number for the carb insulator???

Grenadiers
07-29-2005, 02:26 PM
Another thing to think about, and this was my problem, is to have the stock fuel filter with the return line at the 12 o'clock position. When hot, the gas still wants to move and it will flood the engine while sitting. I didn't have that filter on at first, the return line was plugged, and hard hot starts were pretty common. ONce I put in the correct filter, bingo, no more problems. Hot or cold, it starts up immediately. I have a 2 barrel Holley 500cfm carb with the manual choke and high idle cam. Works great on the stock intake, and has the 1/2 inch insulating spacer.

Jayrodoh
07-30-2005, 06:35 AM
I finally had time to day to work on the new carb. After many runs, jet and rod changes, I got her where I want it. Always has power and low and behold, starts instantly warm without hitting the pedal. Starts great cold too(that was never a problem). Mabye too lean out of the box and the richer mixture helps? But I thought that the idle circuit is seperate from the rest?

Kevin718
08-03-2005, 03:22 PM
This evening I verified that the carb bowl vent solenoid is suppose to be open when the engine is off, and it is suppose to be closed when the engine is turned on.

I also found that while the plunger in the solenoid moves back and forth when power is applied, it does not effectively close. It seems there is a rubber disk that the plunger is suppose to push against the plastic seat of the valve. The rubber disk in my valve is falling apart, and it looks like the plunger has beaten a hole through it.

In addition to that, I broke one of the hose connections off while trying to remove it. So I will be looking for a replacement.

Gawdzilla.
08-03-2005, 05:27 PM
I had this problem too until I re-adjusted the floats (when I had an edelbrock). the float drop was too low, allowing the bowl to empty too much. then the fuel would percolate, in turn causing flooding. Same problem would cause fuel to boil out of the carb. Make sure your drop is 1 1/4" (IIRC...better check that) as well as checking the level w/the top upside down.

jrpitb
08-03-2005, 06:37 PM
jeep guzi you can find the paper based spacers at any parts store if you really want to reduce heat as well as improve the top end power a phenolic(spelling?) spacer is the way to go. I'd call jegs or summit, but they cost about 3 times the standard parts store, one. HRM did a spacer shoot out about two years ago and the laminated wood one came in just behind the phenolic. I guess if your handy with tools but I don't personnaly know about using organic material like wood with fuel, especially not when blow back could occure. Sorry to all for my spellign and grahmer.

Jayrodoh
08-04-2005, 01:58 AM
I was going to try a spacer but my air cleaner is already 1/2" from the hood. I should have gotten a lower profile one.

badaboom
08-04-2005, 03:31 AM
Carb spacer.

This is what I am using, been happy.
I feel better low end with the 4-hole
bit better mid range probably with the fully
open style type.
check summitracing.com
search for part number MOR-64930

[ August 04, 2005, 09:33 AM: Message edited by: badaboom ]

letank
08-04-2005, 09:20 AM
parking with the hood up (open) will aleviate those hot start issues..... it is related to the reformulated gas that boils at lower temp.

Gawdzilla.
08-04-2005, 12:26 PM
Originally posted by letank:
parking with the hood up (open) will aleviate those hot start issues..... it is related to the reformulated gas that boils at lower temp.especially if someone walks off with your distributor cap, or your nice new 200 dollar edelbrock heat sink smile.gif