Running out of time....I'm pinging bad help

[David_H]

I hate to post a new thread on this but my last one is going un-answered and I'm running out of time I have a road trip coming up real soon...

I'm pinging real bad when in 5th gear cruising on the fwy and I just start to accelerate up a hill.. Tried changing the timing no help this wasn't happening with my carb. I looked at my plugs tonight and they look a little lean.

Was I suppose to tell the hand held what A/F targets to run or is it pre set?

I'm going to feel like a big A-hole if I have to remove this thing for my up coming road trip. please please help...... Thanks!

[SoCal]

The A/F targets come preset. But of course, you can adjust them as you see fit. If your actual A/F ratio is reasonably close to the target but it is all just too lean, you might try a lower number for your Cruise target. The instructions go into more detail about how the different A/F targets are used.

[TurboNova]

Air Fuel has nothing to do with pinging. Timing does, if it is pinging you need to take a look at the timing in that area.

[FAST Tech Maxwell]

I second TurboNova.

An overly rich condition can help keep an engine from pinging. There is a good chance the carb was rich during cruise. You can do like SoCal says and richen up the cruise AF Target.

That doesn't really fix the underlying problem, which is too much timing. It could be the hot summer temps making the engine more ping prone. Back up the total advance a couple of degrees and see what happens.

[David_H]

Air Fuel has nothing to do with pinging. Timing does, if it is pinging you need to take a look at the timing in that area.

I have read other post saying running too lean can cause a ping... I also talked to someone from tech support this morning and he said to try to richen it up but I did get the feeling the person I was talking to didn't give a crap about my problem...(may not be the case its just how I felt.)

Right after I installed the efi unit I removed the gear drive from my cam I noticed the gears were set up 4 deg advanced. I asked about it and was told it might be better straight up.... Could this be causing it? I tried all kinds of different timing and it pings at every setting it doesn't ping until the temp gets up around 205 210* I'm at a loss I'm starting to feel like a idiot spending tons of money to make my car run worse..... I thought for sure it had to be a lean issue but since two of you replied its not the way to try and stop the ping what should I do? who can I talk to about this issue with your tech support?

[FAST Tech Maxwell]

If the cam is now more advanced, that will close the intake valve sooner and increase cylinder pressure. More cylinder pressure means more chance of pinging.

You are asking for tech support, and I am trying to give it to you.

Get a timing light, loosen up your distributor, and retard the timing a couple of degrees from where it is right now. Then see how it runs.

[FASTTECH1]

David_H, Do you have a Vacuum advanced distributor? What RPM does the pinging start when it is under load? how much initial timing @ idle and total timing at say 3000rpm do you have?

[David_H]

If the cam is now more advanced, that will close the intake valve sooner and increase cylinder pressure. More cylinder pressure means more chance of pinging.

You are asking for tech support, and I am trying to give it to you.

Get a timing light, loosen up your distributor, and retard the timing a couple of degrees from where it is right now. Then see how it runs.

First off I know you are I didn't mean what I said the way it sounded I was asking if there was any special person to call at Comp cams I didn't mean any dis respect...
I removed 4* and installed the gear set stright up didn't that lower the cylinder pressure?

David_H, Do you have a Vacuum advanced distributor? What RPM does the pinging start when it is under load? how much initial timing @ idle and total timing at say 3000rpm do you have?

I have a vacuum advance distributor the pinging starts when on the FWY in 5th gear when its lugging around 1900RPM right now its int. 18* total is 39* @ 2700RPM I tried it way down as low as 4* still pinged..

Now I did Talk to (I forgot his name) this morning and he gave me some pointers to try but first wants me to upgrade my gas to the good stuff as I'm running 87 octane right now. I thought I had lower compression than I do so I always ran the cheap stuff with the carb. but the carb was way way rich and I guess that can hide detonation....

I'm going to fill it up with the good stuff run it then pull some timing out of it then richen it up a little(plugs shoing lean) if this doesn't help I will be real stumped...

[TurboNova]

First off, again ping has nothing to do with fuel period.

Now that we have that straight, make the cam at 0 or straight up.

Your whole problem lies in the distributor and timing. 39 total is way too much timing for pump gas, even the god stuff. Take that 39 and add more from the vac advance and no wonder it is pinging.

You need to recurve your distributor, different bushings or equiv depending which one it is.


You have not said what the engine is or what your A/F ratio setup is set to. Maybe it is lean but I can tell you for sure if it a domestic V8 the timing is set wrong.

[David_H]

First off, again ping has nothing to do with fuel period.

Now that we have that straight, make the cam at 0 or straight up.

Your whole problem lies in the distributor and timing. 39 total is way too much timing for pump gas, even the god stuff. Take that 39 and add more from the vac advance and no wonder it is pinging.

You need to recurve your distributor, different bushings or equiv depending which one it is.


You have not said what the engine is or what your A/F ratio setup is set to. Maybe it is lean but I can tell you for sure if it a domestic V8 the timing is set wrong.

I'm sorry let me give you some more info: motor is a 89 sbc 350 bored 30 over looks like it was decked as the stamp on the front of the block has been ground off flat top pistons... heads are Casting # 340292.....70's.......Over the counter, angle plug, 64cc chamber the cam is part#
cca-08-433-8 Hydraulic Roller Tappet, Advertised Duration 288/294, Lift .520/.540, The distributor is a Dave's small body HEI with adjustable vacuum can and a lock out, also running a MSD 6a cd box, plugs are autolites # 25 (should I run a colder plug?) RPM air gap with a 1 inch spacer, 3:55 rear gear and a TKO600 trans... I wasn't sure how much info you needed so I gave you everything I could think of....

Oh almost for got the A/F was set at 14. With the carb. my plugs were BLACK like the outer ring, with the EFI they are white see pics... I replaced the gas today and ran the car it didn't ping but the temp never went over 195* so I won't know for sure until I can get it out there on a hotter day....It would ping at all temps but it was real bad when it was around 205-210* I was told to drop down the total to around 34* Whats a good int. starting point? and maybe even try running it with out the vac. advance hooked up as a last resort? Thanks for all the help Its hard for me to type with out sounding like a A hole I'm not that great at the hole typing thing....