Pinging

[AJ/FormS]

That lean burn has exactly one job; To alter the base timing according to load and engine temperature. They should never have given it that moniker ELB; cuz it has no effect on the carb whatsoever.
The carbs were leaned out a bit,sure, but nothing you couldn't change in the field.
If you have made up your mind to ditch it, and have already ordered the parts, then I guess there is no point in talking about it.

So let's get to the heart of your problem.
Since you have tuned it up,let's assume the electrical is ok. That leaves just the fuel system and mechanical.
In post#1,,"So my 5th runs fine, starts on a dime, idles great, and has decent pick-up for still being an ELB 318. But I'm having an issue with the engine "pinging" at partial throttle. If I go over half throttle it stops pinging, and it idles smooth as glass. I'm running ethanol-free, so fuel quality is not an issue, but I am just not sure whether it's timing or fuel-delivery related. It also stumbles occasionally when it's still cold, but once it warms up, it runs fine besides the pinging. I won't be able to work on it for at least 2 months, because I just came back to school for the last chunk of the spring semester. So there's no rush, I just want to know what to look for. Thanks for the input."

-So the underlined items tell us that; A) the compression must be pretty good, and B) the choke must be at least engaging, and C) the low-speed circuit must be pretty close, and D)the timing must be working at least to some degree.
-The red stuff tells us the timing is definitely working, and that there is a compression issue.
-The blue, says that maybe the choke is coming off a bit early, or the low-speed circuit is a tad lean, or the accelerator pump is not quite working right, or the fuel level in the bowl is a tad low, or perhaps the computer has pulled the timing out a tad too much,or just maybe you have a valve-spring issue, or the ignition coil is tired,or dirty, or carbon in the chamber is igniting the mixture at the wrong time.
-Because it is an occasional problem, I'd go with choke,pump, or carbon.
-So now we three strikes indicating compression and or carbon.

Last;let's talk about your new EGR valve, and the new rough running. We are going to try and figure out if the new rough running is due to that valve, the signal to it, or just a coincidence and that you have a new different issue
So the next time it is idling rough, pull the hose off the EGR valve and check it for vacuum.At idle there should never be a signal there.There should also never be a signal there with a cold engine, no matter what the throttle position.So then, did the idle improve with the hose removed and thumbed? If yes, then the vacuum circuit is bad. If no then you will have to prove the valve is actually physically closed. It is possible for a piece of carbon to get wedged between the pintle and the orifice which would allow full-time EGR;and that would be bad,causing idle and possibly low-speed running issues and for sure a warm-up issue. So if the valve is physically closed, then you have a new issue.
Going back to the vacuum circuit; different years have different routings, and I don't know them all, so you will have to research it or perhaps your routing sticker is still affixed to the underside of the hood.
Usually the vacuum is routed through a thermoswitch in the top of the rad. If it has gone bad in the open position;routing vacuum through itself with cold coolant, then it will need to be replaced.The hose is often routed to receive venturi vacuum. This means the EGR has a variable vacuum signal, starting low with a bit of throttle and increasing to maximum flow at some higher throttle position and then falling to zero at higher throttle settings to WOT. Sometimes the hose is routed thru an electrical solenoid and that would then be computer controlled to prevent EGR in certain situations.Sometimes vacuum is routed through a vacuum amplifier.So good hunting if your signal is bad.

 

[rcmaniac791]

I will certainly double check the vacuum signal. I looked at that vacuum routing sticker last night and it said that it does go through a vacuum amplifier. Got to love these 80's emissions systems, right? I drove the car today, and the idle is strange. One second it's pretty smooth, and the next it's really rough. It still pings with small throttle inputs, if I open it up anymore it seems to run fine. I really do think it's carbon build-up in the cylinders. I do remember the last time that I changed my plugs looking in the cylinders and seeing what seemed to be a pretty good amount of carbon. It doesn't ping at all when she's cold, and does it worse in the summer months than the winter months. My next step will probably be to clean out as much carbon as I can.

Last note on the ELB swap: regardless of how the car is running, this is something that I have wanted to do for awhile, just didn't have the time or money. More for a performance upgrade than anything.

Finally, thanks for all the help guys, especially AJ/FormS. I really do appreciate it and I'll keep posting on how things are going.

 

[Jack Meoff]

Did we ever cover what grade of gas you're running?

 

[AJ/FormS]

I know you are excited to ditch the ELB; but truth be told. if that's all you change, there is little to be gained, over a good working ELB.And very likely, after hours and hours of tuning,you will be left with a wee bit of extra power at mid to hi rpms, a loss of hiway mpgs, and perhaps a bit better driveability.
-With the hiway gears that are in it,there is very little pay-off in this endeavor.
Putting a lil more gear in the back will get you many times more satisfaction for just a few dollars more,and waaay less time.
-Some of those girls had 2.45s back there. Going to 3.23s will make the car feel 3.23/2.45 =plus 32% more powerful.That is a huge change. These 3.23s will still leave you some fuel mileage, and with the 2.74 low gear will give you a 8.85 starter gear.( compare that to the possible current starter of 2.45 x 2.74 = 6.71) With the TC that is in there, this will really wake up, off-the-line pick up.There is no single bolt-on for your NA teener that you can do, that will compare to this improvement. None.Even a complete rebuild, engineered for this chassis,will NOT touch this 32% improvement.Further more, with the reduced loading at low rpms, the current ECU will pull out less timing, and the tendency towards "ping" will be much reduced.First gear will still be good to 35 or 40 mph, with a much more exciting pull.
-If you happen to have 2.73s, this will still be a 3.23/2.73 = plus 18% improvement.
-If your hiway use is limited, then 3.55s would be yet better! 3.55/2.73 = plus 30%.This will make the engine feel like it grew by 95 cubes. You would have to shed hundreds of pounds to make it feel this way with the oem gears.

Whatever you do, I won't hold it against you, and I'll still be here to help. I just wanted you to know what I have experienced.Gears rule! Well maybe not, but the right gear for the purpose, will make it seem so.

 

[Jack Meoff]

I know you are excited to ditch the ELB; but truth be told. if that's all you change, there is little to be gained, over a good working ELB.And very likely, after hours and hours of tuning,you will be left with a wee bit of extra power at mid to hi rpms, a loss of hiway mpgs, and perhaps a bit better driveability.
With the hiway gears that are in it,there is very little pay-off in this endeavor.
Putting a lil more gear in the back will get you many times more satisfaction for just a few dollars more,and waaay less time.Some of those girls had 2.45s back there. Going to 3.23s will make the car feel 3.23/2.45 =plus 32% more powerful.
That is a huge change. These 3.23s will still leave you some fuel mileage, and with the 2.74 low gear will give you a 8.85 starter gear. With the TC that is in there, this will really wake up off-the-line pick up.
Further more, with the reduced loading at low rpms the current ECU will pull out less timing, and the tendency towards "ping" will be much reduced.
First gear will still be good to 35 or 40 mph, with a much more exciting pull.
If you happen to have 2.73s, this will still be a 3.23/2.73 = plus 18% improvement. There is no bolt-on for your NA teener that you can do, that will compare to this improvement. None.
If your hiway use is limited then 3.55s would be yet better! 3.55/2.73 = plus 30%.This will make the engine feel like it grew by 95 cubes. You would have to shed hundreds of pounds to make it feel this way with the oem gears.

Agreed 100% Fifth Ave's and Dips of that vintage actually came with 2.24's in the rear if memory serves. For any real performance gains the first thing you need to do is lose those sluggo gears.

 

[rcmaniac791]

I've got the parts on the way, but something that I may do is clean out the engine, check my timing with the ELB system to make sure that's still good, and try to tune what I already have. If I am able to get the current system working good, then I may not do the swap right now. I guess its the whole thing of "if it ain't broke, don't fix it," right?

as far as fuel, I'm running 87 with no ethanol. I did put 89 in the other day, and although it still pinged some, it wasn't quite as bad.

do they make kits for the 7.25 rear end? or would I have to get an 8.25?

 

[Jack Meoff]

I think you need an 8.25.....and I'm betting your car would be a lot happier running premium.

 

[BudW]

Not many parts exist for the 7.25” – but they are out there.
If any plans on any more power output from engine, then you will need to find an 8.25”.

My ’86 5th has 318-2 904 7.25” and 2.24:1 gears.
My ’77 Volare wagon has 318-2 904 8.25” and 3.21:1 gears.
No any additional power - but the wagon will run circles around the 5th Ave (until it runs out of steam) – because of the better gear set.

From a stop/intersection, my wagon will hole-shot many a un-expecting ponycar, and the 318-2 wont peel out (any more horsepower, it might).

I can’t wait to put my 2.94:1 8.25” differential into my 5th Ave! (Actually trying to find an 8.75” to put in it, but have the other differential already). I might still get beaten by a bicycle rider from a stop - but won’t quite be as humiliated.

BudW

 

[AJ/FormS]

There is a good side to humiliation; you don't bleed from it, and the pain only lasts a short while, and then you get to pass it along to someone else. Just don't let that someone else be someone you love.....

 

[AJ/FormS]

My wife's cousin came to me in about 1978 or so, with a teener-Demon. Now that teener was pretty strong as a stocker. But he asked for my help. I installed a 4.10 into her, and that was the end of the story. He came back really excited!Make that really, really,reeeeeeally, excited.
4.10/2.76 = plus 48% more torque multiplication. That's like turbo-boost!

 

[rcmaniac791]

and I'm betting your car would be a lot happier running premium

I agree with you there Captain.

I don't have the time right now for a rear-end swap, but I will definitely plan on doing it at some point. I will say that even with the highway gears, I can still manage to get the tires to chirp occasionally!

Last non-related thing: I had to run to the store real quick the other day, and instead of burning my own gas, my dad let me drive his Civic. I felt like less of a man, and that I should be eating tofu and commuting on a fixed-gear bicycle. lol

 

[AJ/FormS]

I hope you're still liking girls

 

[rcmaniac791]

only the best

 

[rcmaniac791]

Alright y'all, here's what happened:

New MSD ready to run distributor installed, and a re-manufactured carter 2bbl that was supposed to be on a Cordoba. (no electrical connectors) The install went really smoothly, timing set properly, and the carb bolted right on. My idle has smoothed out an insane amount, and I don't have to wait forever for my car to warm up before it's running good. Doesn't stumble any more, and just generally runs much better.

Now to the pinging: The carb and dist. did help quite a bit, but there was still a slight ping. I put premium gas in it, and pretty soon after the ping started to go away. I bought a can of seafoam and added it into the gas, figured it would be less violent that way. Nevertheless, things are doing a lot better than they were before.

And for the fun stuff, pictures! no wonder it wasn't running right, these parts are crusty!

 

[AJ/FormS]

Well, good on you!

 

[Jack Meoff]

Nice work.

 

[volareandgtcat]

Well done!