Hi Folks,

I'm making my way through repairs here, one at a time...and I really have very little experience ever working around carburetors and/or timing. (Just finished replacing the steering gearbox this morning, and will be doing the heater core this afternoon)

Anyway, truck starts and runs fine, but if I put any kind of a load on the engine it pings like crazy. Driving down the road on level ground, it sounds fine. Try to accelerate or go up a hill, and it just starts making a racket.

I have both Haynes and Factory Service manuals on the way, but they won't be here for at least another week.

This may be totally unrelated, but my first question is what is this device on the side of the carb? Looks like somebody fixed it up with JB Weld, but the grey wire has been cut off, and there is a red wire with a blue plug that is close by, but not connected to anything. What is this? And should it be replaced and/or connected?

Second question, if the device in the picture is completely unrelated, what is my next step in diagnosing and resolving the pinging?



Any help for an old truck newbie would be appreciated.

 

That device is more than likely the high idle solenoid for the A/C system. Does or did this truck have A/C? It makes the engine run faster so the A/C works better and the engine idle doesn't drop too low from the load of the compressor.

Your pinging can have several causes. The timing can be too advanced. It needs to be checked. Also, the EGR valve not being hooked up and working will also cause it to ping. There are a few work arounds to try and keep it from pinging if you want to leave the EGR not working. Setting the timing a little conservative, putting a lower temp thermostat in it, and buying a small non-emissions 4 bbl carb and intake will also help make it quit pinging.

 

No sir, no AC, ever.

OK, thanks, I guess I had better buy a new timing light. I had one but sold it many years ago as I didn't think I'd ever use it again.

EGR is still connected...whether it works or not is another story. All of the emissions equipment is still intact on this truck. I plan to get rid of everything and simplify matters this winter, but I'd like to make it driveable for the time being so I can get everything else sorted out.

 

Is there a non-emissions 2bbl available that will bolt on to my existing intake?

 

It's a Throttle Kicker/Curb Idle Solenoid. It steps up basic curb idle for AC, PS, engine overheating and the like. It may also have a dash-pot feature (many different variations).

On your vacuum advance canister, the actual ported/manifold vacuum advance can be adjusted to lessen/prevent pinging after correct basic timing is set. Also pull the vacuum source for the EGR Valve and plug it. Test drive. If lazy or not calibrated correctly it can lead to pinging.

The carb you have (2150) can be re-calibrated easily.

 

Excellent, thanks for the reply.

I have to pick up a timing light tomorrow, and then try to clean the rust off the harmonic balancer so I can see what they heck is going on. It looks like it will be hard to see as the pollution pump is above the alternator and blocking any kind of easy view.

I have a factory service manual on the way, so hopefully that will have a vacuum diagram and some details for me to work with.

I plan on doing some modifications this winter, but I'd like to get it running as good as it can run as is for now so I can tool around with it a little bit. New plugs and wires and everything likely wouldn't hurt either.

I'll check the timing and the vacuum and report back.

Thanks guys.

 

That is the right way to do it. Many just go in and start ripping stuff out not knowing how any of the stuff works or if the motor ever ran right to start with.


I have also seen that solenoid to set the idle speed even with out AC.
They use it to set the idle speed when in gear.
When the motor was shut down the solenoid turns off and the idle or should say the throttle closes more.
This was done because of run on or "dieseling" that sometimes can happen when the idle is too high but cant be set lower when in gear or it will stall.


How old is the gas in the tank? Old gas can also make it ping.
For now as said disconnect the EGR and plug the hose.
You can also do it for the vacuum advance to see if that helps but only do the EGR or advance 1 at a time to see if either makes a change. If you were to do both at the same time you would not know what made it stop.
Dave ----

 

Here is the vacuum diagram from my 84 with 302

David


vacuum layout



vacuum and emissions tag

 

Another cause of pinging is the use of higher heat value spark plugs, than stock.
This isn't likely to cause severe pinging like you have, alone........but would contribute to the problem.

I had a steadily worsening pinging problem that was caused by a bad valve stem seal; this allowed traces of oil into the cylinder, which effectively lowers the octane rating of the gas, causing pinging.

Rockauto is showing two non-emissions (Canadian spec) carbs for your year truck, one for auto & one for manual.........https://www.rockauto.com/en/catalog/...arburetor,5904.....but if you have feedback carb set-up with EEC III or TFI, your ignition would need to be converted to Duraspark II, & the computer taken out of the equation before you changed carbs.

But it shouldn't be necessary to do this just to fix the pinging.

 

Ok, I've looked around on Rock Auto before, but I've never actually purchased anything from there.

Looking at the carbs you linked to, how are you identifying the non-emissions Canadian spec carbs? I see a Canadian flag next to two line items...I assumed that was telling me the location of the items?

This truck is manual trans.

It is my plan to simplify things under the hood in the near future. I'd like just a basic carb and ignition so I can remove all of the other crap in there.

 

Look for a pre 83 Canadian spec carb as they are not really emission calibrated. Starting in 83 more stringent emissions started to be enacted on light duty trucks in Canada. Even better are carbs pre 81. As those are a true non emmsions carb.

In 81 they started to push emissions on trucks. Even though official HP ratings did not change between 80 and 81 in Canada there was a difference.

Ideally if you can afford it you want to match the distributor and carb.

A good true non emissions combo for the 302 in a truck is.


https://www.rockauto.com/en/catalog/...arburetor,5904

Carb AUTOLINE C8077A

And

https://www.rockauto.com/en/catalog/...stributor,7108


Distributor AUTOLINE D4043

These are pre EGR, pre evap, pre lean fuel air mix, unleaded calibrated distributor and carb. It is equivalent to early 70's U.S equipment only calibrated for unleaded gasoline.

For less than $300 you can replace the carb, dist and remove ALL the emissions equipment on the truck. You will see jump in power and fuel economy. And have no worries about pinging (detonation)

Autoline is Canadian re-builder Headquartered in Winnipeg Manitoba .
Since you are in Canada try shopping around at some the auto parts stores and see if you can beat the Rock Auto price on the Autoline stuff.

 

Excellent info, thank you!

So, That C9077A carb says it's for an automatic trans? Does this matter if it is installed on a manual trans truck? What is the difference?

Would my existing fuel line work? My truck has a hard steel line from the pump to the carb currently. I assume my existing breather would fit as well?

Regarding the distributor, it says without cap adapter. Does that mean re-use my existing or purchase separately?

And, what is the difference between the steel and cast iron gears?

Thanks for the info, this is great.

 

Yes, good thing you stopped here first. Ripping stuff out to make the engine "look better" is a sure way to lead to problems that you already have. Unless your timing is radically off, I am betting your EGR is not working, and the cause of the pinging. Think twice before removing it. Learn how it works, it should be easy to get it going again. Then you can use the carb you have.

 

The only difference between the auto and manual carbs is the Auto Carbs have the kick down lever for the auto trans. You can use an Auto carb with a manual trans no issues. The kick down lever just wont be hooked up to any thing.
You can not use a manual carb with an auto trans as you won't have have the kick down lever to down shift the trans when you mash the go pedal to the floor.

Yes this carb should be direct bolt on no changes necessary to fuel lines or any thing else. And yes your air cleaner will bolt on.
It is the same carb as the one currently on your truck just in a different calibration/tuning for no emissions.

The Autoline Dist comes with No adapter (bottom part of the Duraspak distributor cap) and no distributor cap. You can reuse your own adpater and cap if in good shape or replace with new totally your call.

Here they are new

1984 FORD F-150 5.0L 302cid V8 Distributor Cap Adapter | RockAuto

1984 FORD F-150 5.0L 302cid V8 Distributor Cap | RockAuto


As a rule of thumb, Steel or bronze distributor gears are used with Roller cam shafts. Cast iron gears are used with Flat tappet cam shafts.
Some aftermarket cams may specify Steel or bronze or even composite gears.

The stock cam in your truck will use a cast iron gear and this is what will be supplied on the selected re-man distributor.

 

Not likely in this application there is no EGR spark control the Dist is fed strait ported vacuum no switching to retard when the EGR is non op.

So that is an unlikely cause of the pinging. This is more likly a timing/carb or high tension lead issue (cross firing). Fords use ported vacuum for dist advance the full manifold vac advance is a GM thing.