What type of carb spacer should I buy?

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tallygrandwag
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Joined: Mon Oct 25, 2021 9:03 am

What type of carb spacer should I buy?

Post by tallygrandwag » Tue May 24, 2022 11:20 am

I have a 1990 GW. As the weather has gotten hotter, I find it is more and more difficult to start the Jeep after it has been running, then sat for more than 10-15 minutes. Most of the forum posts I've read say adding a phenolic spacer should help keep the carb cooler, resulting in easier starts when hot.

I have an AMC 360 with an edelbrock performer intake manifold and an edelbrock 1406 carb. I see open carb spacers (one big hole) and spacers with 4 holes on the edelbrock site, but they don't seem to explain the difference. Which type is the right type for my set-up? Anyone else have a carb spacer already on their rig with this same set-up? If so, what did you buy? Thanks.
My 1990 Grand Wagoneer maintenance log on MyCarMaintenanceLog.com:
https://www.mycarmaintenancelog.com/?v= ... FA2FEE1395


will e
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Re: What type of carb spacer should I buy?

Post by will e » Tue May 24, 2022 11:27 am

Howdy. What do you mean by 'more difficult to start the jeep'? Do you have to crank it for a while or does it crank slowly? How does it run once you get it started.

If the Edelbrock you have is one with a split plenum design (their is a divider separating the left and right side), then use a spacer with holes. This will help make sure the manifold is working as designed.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge


Topic author
tallygrandwag
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Re: What type of carb spacer should I buy?

Post by tallygrandwag » Tue May 24, 2022 11:44 am

Hi will e. It starts great when it has been sitting over night, one turn of the key and it is running in less than a second. When it has been running for a while and the outside temperature is hot, if I park and leave it for 10-15 minutes or more, then I have to crank and crank and crank to get it to start. Sometimes it takes 8-10 seconds of cranking before it will fire up. When it finally fires, I have to give it extra throttle to keep it running for the first 30-45 seconds or it will stall, after that it runs fine. This makes me think it is a hot fuel issue, that is why I am planning to try a spacer and see if that helps. Also I forgot to mention in the original post, I have an electric fuel pump too.
My 1990 Grand Wagoneer maintenance log on MyCarMaintenanceLog.com:
https://www.mycarmaintenancelog.com/?v= ... FA2FEE1395

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Stuka
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Re: What type of carb spacer should I buy?

Post by Stuka » Tue May 24, 2022 11:45 am

will e wrote:
Tue May 24, 2022 11:27 am
Howdy. What do you mean by 'more difficult to start the jeep'? Do you have to crank it for a while or does it crank slowly? How does it run once you get it started.
He is describing what happens when the fuel evaporates out of the carb, so the pump has to pump up fuel before it will start.
tallygrandwag wrote:
Tue May 24, 2022 11:20 am
I have a 1990 GW. As the weather has gotten hotter, I find it is more and more difficult to start the Jeep after it has been running, then sat for more than 10-15 minutes. Most of the forum posts I've read say adding a phenolic spacer should help keep the carb cooler, resulting in easier starts when hot.

I have an AMC 360 with an edelbrock performer intake manifold and an edelbrock 1406 carb. I see open carb spacers (one big hole) and spacers with 4 holes on the edelbrock site, but they don't seem to explain the difference. Which type is the right type for my set-up? Anyone else have a carb spacer already on their rig with this same set-up? If so, what did you buy? Thanks.
If you have a MToD subscription, engine masters has done a lot of testing on various types of spacers. They can have quite the impact depending on the intake and engine RPM range. For our engines, and the RPM range that they run, and the dual plain intake, I would probably go with a four hole designed spacer. An open spacer will give a bit more top end, but you will lose some lower RPM throttle response and torque.
2017 JKU Rubicon Lifted and stuff
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ


Topic author
tallygrandwag
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Joined: Mon Oct 25, 2021 9:03 am

Re: What type of carb spacer should I buy?

Post by tallygrandwag » Tue May 24, 2022 11:49 am

Hi Stuka. Thank for the tip on Engine Masters. I love MToD. I'll definitely look up the one on spacers.
My 1990 Grand Wagoneer maintenance log on MyCarMaintenanceLog.com:
https://www.mycarmaintenancelog.com/?v= ... FA2FEE1395


letank
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Re: What type of carb spacer should I buy?

Post by letank » Tue May 24, 2022 1:58 pm

Not too sure about your air filter configuration, but with the extra spacer, you may want to check that you can close the hood!

Corrected below, does not apply to your set up...but beware

With the stock air filter canister, an edelbrock intake (which I forgot the type: checked a 2131) and the motorcraft 2150, I could not close the hood! with the adapter between the edelbrock to the motorcraft (pict to follow)
CarbSpacPV2edelbrock .jpg
in my case the whole think was a failure, the adapter did not match the motorcraft and there were many potential air gaps
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Last edited by letank on Thu Jun 02, 2022 12:10 pm, edited 4 times in total.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (228 Kmiles... the running test lab)
See Engine bits , Fuel and brake lines, Body work, Trany and TC


Topic author
tallygrandwag
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Re: What type of carb spacer should I buy?

Post by tallygrandwag » Tue May 24, 2022 2:03 pm

Good point letank. I am still running the stock air filter canister. I'll do some measuring before buying a spacer.
My 1990 Grand Wagoneer maintenance log on MyCarMaintenanceLog.com:
https://www.mycarmaintenancelog.com/?v= ... FA2FEE1395

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devildog80
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Re: What type of carb spacer should I buy?

Post by devildog80 » Tue May 24, 2022 3:12 pm

And if you are not using a bypass fuel filter, I would consider that if still having troubles, after you redo your carb mounting.
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving than waiting for modifications
Somebodys' bad answer, should prompt someone else to give the right answer, but no answer at all helps no one.


letank
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Re: What type of carb spacer should I buy?

Post by letank » Tue May 24, 2022 3:26 pm

Make sure that your fuel filter return is at 12 o'clock... then check your fuel pressure, if you have a mechanical fuel pump, it is cooking next to the exhaust manifold, and depending on its functionality it might be limit when it has cooked... this is why a lot of us have switched to an electrical fuel pump.

A quick and dirty test: plug the fuel return line and see if it improves your restart
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (228 Kmiles... the running test lab)
See Engine bits , Fuel and brake lines, Body work, Trany and TC


will e
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Re: What type of carb spacer should I buy?

Post by will e » Tue May 24, 2022 5:33 pm

Instead of a spacer I installed a 'heat shield'. There are a lot of options. It is very important that you check that none of the linkage binds after installing a shield. (Test install, verify linkage isn't binding then tighten down).

You mention the electric fuel pump. Does the pump run when the ignition is turned on or do you have it so it only runs when cranking and while the engine is running? One trick you might try is get the engine warm, let it sit, turn on the electric fuel pump and let it pump for about 10 seconds and then crank. If it starts the gas is boiling out, if it doesn't start you have a different problem.

What electric fuel pump are you using? What is the PSI rating?

The fuel filter advice is one of those discussions similar to ported vs manifold vacuum. There is no single agreement but that's okay because what works in some cases doesn't work in others. I removed my return fuel filter. I have a Holley Truck avenger. I installed a fuel pressure gauge right at the carb. With the return fuel filter I only had about 3 psi. The holley likes closer to 7 psi. I swapped in a non-return fuel filter and no longer have starting or vapor lock issues. Actual results will vary. On a 100% stock setup I would advocate for keeping the return line but when folks have swapped in aftermarket carbs I tell them my fuel filter story.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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coolhand75
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Re: What type of carb spacer should I buy?

Post by coolhand75 » Tue May 24, 2022 7:41 pm

tallygrandwag wrote:I have a 1990 GW. As the weather has gotten hotter, I find it is more and more difficult to start the Jeep after it has been running, then sat for more than 10-15 minutes. Most of the forum posts I've read say adding a phenolic spacer should help keep the carb cooler, resulting in easier starts when hot.

I have an AMC 360 with an edelbrock performer intake manifold and an edelbrock 1406 carb. I see open carb spacers (one big hole) and spacers with 4 holes on the edelbrock site, but they don't seem to explain the difference. Which type is the right type for my set-up? Anyone else have a carb spacer already on their rig with this same set-up? If so, what did you buy? Thanks.
Engine masters. Did a show on them. Good program


1975 jeep j10
360 4bbl
Turbo400
Qudratrac w/part time kit
Dana 44’s front and rear

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devildog80
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Re: What type of carb spacer should I buy?

Post by devildog80 » Thu May 26, 2022 9:36 am

Just throwing this on the heap, as maybe it will be helpful.

Run these as designed-
"Sorting the charcoal canister and purge valve out fixed my hard hot starting"
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving than waiting for modifications
Somebodys' bad answer, should prompt someone else to give the right answer, but no answer at all helps no one.


Topic author
tallygrandwag
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Re: What type of carb spacer should I buy?

Post by tallygrandwag » Thu May 26, 2022 11:13 am

Will e. I'm running a small Holley Mighty Mite Fuel Pump. The manual says it runs 32GPH @ 4-7 PSI. I do not have a return filter. It is just gas in, then gas to the carb. It is wired to run when the ignition is on. I always let it run for 5-10 seconds before I try to actually crank the engine. It is mounted to the frame rail under the driver, so, it is easy to hear. Everything starts great when the engine is cooler. My problem only happens after it has been running and then I let it sit for a while. That is why I think it is a heat issue.

You mentioned that you have installed a heat shield for your carb. Can you post some photos of your set-up. Was the heat shield something you bought or made? Thanks.
My 1990 Grand Wagoneer maintenance log on MyCarMaintenanceLog.com:
https://www.mycarmaintenancelog.com/?v= ... FA2FEE1395


rocklaurence
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Re: What type of carb spacer should I buy?

Post by rocklaurence » Fri May 27, 2022 8:57 am

I have the Performer manifold with a Street Demon cab, Holley Mighty-mite with the return filter aaaand a 2" spacer [the spacer made a noticeable difference with the carb-performance-wise] and it helps with Heat Soak. Get a composite spacer and 5/16 threaded rod. The extended carb studs are never long enough.


will e
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Re: What type of carb spacer should I buy?

Post by will e » Fri May 27, 2022 3:31 pm

tallygrandwag wrote:
Thu May 26, 2022 11:13 am
Will e. I'm running a small Holley Mighty Mite Fuel Pump. The manual says it runs 32GPH @ 4-7 PSI. I do not have a return filter. It is just gas in, then gas to the carb. It is wired to run when the ignition is on. I always let it run for 5-10 seconds before I try to actually crank the engine. It is mounted to the frame rail under the driver, so, it is easy to hear. Everything starts great when the engine is cooler. My problem only happens after it has been running and then I let it sit for a while. That is why I think it is a heat issue.

You mentioned that you have installed a heat shield for your carb. Can you post some photos of your set-up. Was the heat shield something you bought or made? Thanks.
That's interesting. Not unsimilar to my setup only I have a Holley Truck avenger carb. I don't have hard starting when hot, even here in AZ.
If the fuel was boiling out, letting the fuel pump run for 5 to 10 seconds would get new fuel into the bowl.
I bought a heat shield, there are different ones available. I am not sure it is helping, I can't remember if it fixed the vapor lock issue or not. But I've left it on.

I would do a bit more investigation before tossing parts at it. Some ideas:

With the engine cold, turn on the fuel pump but don't start the engine. Turn off the fuel pump and check the float level and/or pump the accel pump while looking down the carb. How many pumps until it was empty? Try again after the engine is hot. See if you get the same number of pumps and/or check the float level. (This will tell you if the fuel bowls are filling up.) You might also try again when it is hot but without turning on the fuel pump, you should get about the same number of accel pumps.

Use an IR gun to read the temp of the carb. Check the temp of the fuel filter as well.

When it is hot, check the spark. Just to be sure.

ANd you can always spray some starter spray into the air filter when the engine is hot. If you are having a lean fuel issue it should start and run for a few seconds.

Have you checked the operation of the choke? Make sure the choke isn't coming on with the hot start ups. (Seems unlikely but would explain some of your issues)
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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devildog80
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Re: What type of carb spacer should I buy?

Post by devildog80 » Mon May 30, 2022 12:34 pm

Will e,

Regarding your fuel filter placement, as you are not using a return type, did you place your filter down just off fuel feed at the frame, or is it still on top of the engine just forward of the carb?

Thinking when it comes time for me to put my fuel feed system back together, and not using a bypass filter with electric pump, it looks like the filter would be coolest just off the frame connection.
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving than waiting for modifications
Somebodys' bad answer, should prompt someone else to give the right answer, but no answer at all helps no one.


letank
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Re: What type of carb spacer should I buy?

Post by letank » Thu Jun 02, 2022 12:15 pm

devildog80 wrote:
Mon May 30, 2022 12:34 pm
Regarding your fuel filter placement, as you are not using a return type, did you place your filter down just off fuel feed at the frame, or is it still on top of the engine just forward of the carb?
My fuel filter is on the fender, and the fuel line is insulated with the common home pipe insulation
Image
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (228 Kmiles... the running test lab)
See Engine bits , Fuel and brake lines, Body work, Trany and TC


will e
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Re: What type of carb spacer should I buy?

Post by will e » Thu Jun 02, 2022 12:19 pm

devildog80 wrote:
Mon May 30, 2022 12:34 pm
Will e,

Regarding your fuel filter placement, as you are not using a return type, did you place your filter down just off fuel feed at the frame, or is it still on top of the engine just forward of the carb?

Thinking when it comes time for me to put my fuel feed system back together, and not using a bypass filter with electric pump, it looks like the filter would be coolest just off the frame connection.
Right now it is sitting just above the valve cover. Never even occurred to me to move it. I probably should!
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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devildog80
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Re: What type of carb spacer should I buy?

Post by devildog80 » Thu Jun 02, 2022 12:22 pm

And looks like you are using the return line too.

Starts and runs good at this location?

I'm sure if it did not, you would change it.

Thanks for the response.
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving than waiting for modifications
Somebodys' bad answer, should prompt someone else to give the right answer, but no answer at all helps no one.

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devildog80
Posts: 309
Joined: Wed Apr 13, 2022 2:41 pm
Location: Apache Junction AZ

Re: What type of carb spacer should I buy?

Post by devildog80 » Thu Jun 02, 2022 12:30 pm

As long as it works, we do not usually move stuff around.

As that is nearest task I have ahead of me, is installing the tank after cleaning, then rebuild fuel feed/return (might start out not using return but want to hard plumb the metal lines on the block together now, if needed later) from the frame up to the carb.

Any ideas to keep anything cooler in AZ desert in the summer time, is worth looking into :)

Thanks
will e wrote:
Thu Jun 02, 2022 12:19 pm
devildog80 wrote:
Mon May 30, 2022 12:34 pm
Will e,

Regarding your fuel filter placement, as you are not using a return type, did you place your filter down just off fuel feed at the frame, or is it still on top of the engine just forward of the carb?

Thinking when it comes time for me to put my fuel feed system back together, and not using a bypass filter with electric pump, it looks like the filter would be coolest just off the frame connection.
Right now it is sitting just above the valve cover. Never even occurred to me to move it. I probably should!
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving than waiting for modifications
Somebodys' bad answer, should prompt someone else to give the right answer, but no answer at all helps no one.

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