Need troubleshooting help...
 

Drive car everyday and no problems, until now...

After car has warmed up, there's a pinging under acceleration (from 1/4-throttle up) and it seems to have started with the cool weather a few weeks ago. I pulled timing back 14º, then 12, then 10...now it's 9º and not better. I also have played with fuel-pressure, but no help. Then I suspected the C&L meter, so I took the cold-air-kit elbow off and just mounted the filter on the end of meter...no better. Then I changed the electronics in the C&L...no better. I put in new plugs...no better. Car is fine under normal driving, but step on it a little, especially under a load like 3rd or 4th gear, and it sounds like I have 87-octane gas...I have tried some other gas stations too and nothing helps.

Here's the kicker: When car is still fairly cold in morning, I cannot get it to do it...runs strong and pulls smooth..once it gets up to operating temp...it does the knock/ping.

Only other thing I changed around the time it started doing this is the electric fan. Could there be a problem with not enough airflow over the aluminum heads? The fan keeps water temp way cool in traffic but maybe it's not doing enough airflow...
Or could it maybe be the fuel-pump is going south (again) and the preignition is just a lean knock?

My only other guesses would be a bad TFI? or distributor?

I have always fixed troublesome things like this with timing adjustments, better gas, plugs, cap/rotor, etc.. but It's not working. Feedback please.

Re: Need troubleshooting help...
 

Just a grasp buyt what about the ECT or ACT sensors?

Re: Need troubleshooting help...
 

out of curosity, how many miles are on the timing chain?

Re: Need troubleshooting help...
 

hey guys... that sounds like part of the same problem i had 3 months ago when my hall effect sensor inside my distributor came loose, and contacted the cam vane... you should check that out, i am half positive that is your problem...you have already checked everything else so... you might as well... i tore my whole motor down before i found that out

Re: Need troubleshooting help...
 

Unplugged CTS, then ACT, then both together, thinking the CPU might put default on it but it still pings, only with the check engine light on.
Timing Chain is a Crane piece, maybe 10-15k on it.
I will check distributor today; fortunately I have another to try.

Re: Need troubleshooting help...
 

well???

Re: Need troubleshooting help...
 

I took distributor apart (what I could) and cleaned up. It's spinning freely and really it wasn't that bad, looked almost new. Put cap & rotor in for good measure and it seemed to help a little. But still pings a bit under 1/2-throttle or more. Next thing I'm trying is the TPS. I have a new one anyhow so it can't hurt. I will update.

Re: Need troubleshooting help...
 

Carbon build up?
Bad winter fuel?
:dunno:

Re: Need troubleshooting help...
 

I have seen loose O2 sensors cause the exact same problem.(Exhaust leak before the O2s)

Re: Need troubleshooting help...
 

:think: on the O2 sensors...I also think they're in need of replacement. Did find out though with the warmer air temp like yesterday, hardly any pinging. Cool air tonite...back to square 1. ACT will go next.