New EB, trying to get everything tuned

[spreadmonkey]

I'm continuing this from another thread about the EB I just purchased. It was tough to start and keep at idle, and after a short drive it overheats.

Some suggested that before I try to diagnose the overheating I should make sure to tune the timing, A/F mixture, and Vacuum hoses, etc.

So I'm starting with A/F...(i know didley about carbs so please bear with me)

The truck came from Colorado a few months ago, and the PO who bought it from there and sold it to me said that the carb had been adjusted for CO elevation.

I adjusted the idle mixture screws to a richer position, and now she's starting up more easily and idling smoothly.

I think now I need to replace the metering rods and jets, also. I think he has them set two stages lean. That's just a guess for CO altitude (5000+feet).

I have the calibration kit and with the manual I think I can figure out how to calibrate it for Texas elevation. Should I be running it slightly rich, or just stock? Do I need to change the rod springs also? Anything else I should adjust?

 

[67PONY]

Have you pulled any of the plugs to see what they look like? If it's calibrated as lean as you say, there should be evidence on the plugs.

 

[70_Steve]

So, if you're talking metering rods, you've got to have a Carter/Edelbrock carb. Pull the metering rods and see where you're at. Might want to pull the jets out too, just to make sure you know what jets you're starting with. To get the jets out, loosen them with a screw driver, then use an orangewood stick (the thing the girls use on their nails) to stick in the middle of the jet to finish unscrewing, then lift out.

I'm in Phoenix (1200 ft elev), and am one step leaner than stock, and am still a little on the rich side.

The metering rod springs, will change how quickly you go from cruise A/F ratio to power. You will feel this when you drive down the road and then step on the gas. Accelerator pump adjustment also has an effect.

 

[dewshan]

I would make sure the timing is set properly first before you adjust the carb more. The timing advance is different between high altitude co and low altitude TX. It is easy to do. Do you have a repair manual yet. I have a Haynes and it will tell you step by step how to set it. It could help if you have a timing light also. pm me if you want the steps to make sure timing is right.

 

[cs_88]

It would be a good idea to contact Edelbrock tech support and give them all the info you can. They can recommend a good starting point.

 

[spreadmonkey]

I would make sure the timing is set properly first before you adjust the carb more. The timing advance is different between high altitude co and low altitude TX. It is easy to do. Do you have a repair manual yet. I have a Haynes and it will tell you step by step how to set it. It could help if you have a timing light also. pm me if you want the steps to make sure timing is right.

I checked the timing with a timing light and it was set at 20 BTC. I backed it down to 8 BTC by turning the distributor CCW. I dont have a haynes manual, I didn't know they made them for the 74. I have the ford manuals for a '73, one year off shouldn't make a difference, but the engine is from an '89, crown vic I think

 

[spreadmonkey]

Have you pulled any of the plugs to see what they look like? If it's calibrated as lean as you say, there should be evidence on the plugs.

Not yet, but I probably should before I mess with the carb too much, good point %)

 

[dewshan]

I checked the timing with a timing light and it was set at 20 BTC. I backed it down to 8 BTC by turning the distributor CCW. I dont have a haynes manual, I didn't know they made them for the 74. I have the ford manuals for a '73, one year off shouldn't make a difference, but the engine is from an '89, crown vic I think

I checked-I have chilton manual for the bronco not haynes. I was remembering my old MG days! Those were not good days! The manual covers most early bronco years. Make sure you have the advance hose disconnected and plugged when you set the base timing?

So is it running better at the new timing?

 

[spreadmonkey]

I checked-I have chilton manual for the bronco not haynes. I was remembering my old MG days! Those were not good days! The manual covers most early bronco years. Make sure you have the advance hose disconnected and plugged when you set the base timing?

So is it running better at the new timing?

Ya, it is running better and at a slightly lower RPM (1000) which is still kinda high IMO but is that normal?

 

[cgbexec]

I was told normal idle for a stock 302 is about 750. Mine is not stock and I can't get it to idle below 875 to 900.

 

[spreadmonkey]

Mine is a 351W

 

[cgbexec]

1000 sounds high for a 351W as well. Is there a throttle stop screw on the carb that you can back off to drop the idle?

 

[spreadmonkey]

I still haven't pulled the plugs yet. I have been out of town for over a week, and wanting to get back to working on the bronco the whole time.

Got back yesterday and my new fan had arrived (old clutch fan was definitely shot so I figured it was good to go ahead and get it). I didn't have much time to wrench before bedtime but enough to put a fan on so I did that. Drove it around for 20 minutes, up and down some steep hills in my neighborhood, never faster than about 40 but maintained some good RPMs with all the hills. The temperature stayed right around 170-180. Got to 190 once but quickly came back down to 180. It was 50 degrees outside so I would still like to see a little bit better results but that was better than before, at least.

 

[cgbexec]

1) What fan are you running?
2) Are you running a clutch?
3) What radiator are you running?
4) What schroud are you running?
5) What temp Thermostat are you running?

 

[cgbexec]

I am running the following:

1) Howe 4 core Aluminum Rad.
2) Flex-O-Lite 7 Blade Flex Fan
3) 1.5" spacer - no clutch
4) Stock style fan schroud
5) 180* Robert Shaw thermostate
6) 16lb. Summit Radiator Cap

It has been in the upper 70s and lower 80s for that last couple of weeks. I have not seen the temperature go over 182 degrees although as long as she stays under 200 you should be just fine.

 

[spreadmonkey]

Cant answer all those from here at the office but here is what I know:

1. Gotta look again but per PO and receipts its a High Pressure Ron Davis Racing Radiator. It's definitely aluminum.
2. Flex-a-lite 18.25" 7 blade Flex Fan, with 1.5" spacer and no clutch (me)
3. Not exactly sure if the shroud is aftermarket or stock, but I'm guessing it is stock since the bolt holes were moved to accommodate the new radiator.
4. No idea about the thermostat
5. Dont recall seeing a brand name on the radiator cap, but I have never seen one like it. It has a probe looking thing that hangs from a spring on the inside of the cap. If you pull on the spring it opens a gap in the cap. I assume that's part of a pressure release feature but that's just a guess.

 

[spreadmonkey]

There's an emblem on the front of the radiator. Cant identify it from the picture but maybe you can: http://flickr.com/photos/31492820@N07/3137934271/

 

[76 bronco J]

There's an emblem on the front of the radiator. Cant identify it from the picture but maybe you can: http://flickr.com/photos/31492820@N07/3137934271/

>>> that's the wild horses logo ...... here's a link to the radiator cap with the I believe your talking about in the last post ...... www.wildhorses4x4.com/product/Rad_Cap_EME_14lbs/Aluminum_Radiators .... main thing for long aluminum radiator life is to use a distilled water mix & never tap water or better yet use the premix antifreeze with a deionized water mix....

 

[spreadmonkey]

Thanks for the ID. After seeing your picture I can't believe I wasn't able to identify it myself. I think I was blinded by what the PO said. That looks pretty similar to my radiator cap also.

I didn't mention that I also drained both the radiator and the overflow reservoir while I was installing the fan. Cleaned the reservoir out because it was dirty, and refilled everything with 1/2 distilled water 1/2 coolant. I know for a fact the PO used tap water. I even had to tell him to stop because he was topping it off with a garden hose before I test drove it. So, I knew I needed to replace that quickly, hopefully it isn't too late. Never thought i would use Ozarka on a truck but it was the only distilled water they had, lol.

 

[cgbexec]

Make sure you have a sacrificial zinc installed in the radiator. Usually they install where the drain would thread in.

If you saw 190 on the temp gauge you are fine. It is less about the number than a pattern. If it always fluctuates between 180 and 190 and then all of the sudden its running 200, then you know something is going on. Just keep an eye on it.