Chattering (pinging) under acceleration

[sly]

Can't you just clean the MAF sensor (that tiny wire ) with the unit in the air hose?

no. air hose may be high enough pressure to break the thin wires.

Wouldn't it throw a code for that?

nope. There's no backpressure sensor.

[DerekTheGreat]

My car had pinging like this. Turns out it was the catalytic converters had broken up and it was the broken metal inside rattling. Drove myself crazy checking everything else and when I took it to get straight piped it fixed the problem when I was even expecting it

This happened to my brother's old '93 too. Well his cats were plugged up so I guess in the process of cutting them out they broke pieces off that ended up in the resonators that made gawd awful noise under acceleration up until he sold it.

[porschpow]

I guess I will start with the basics:

Thermostat
Clean MAF sensor
Inspect Plugs
Measure temps @ thermostat (before I put in new thermo)

[His Royal Ghostliness]

I did notice that after 2-3 days of my car sitting, when I started it, it take quite a few cranks to turn over but when it did, it was barely idling and sounded like it was missing on a cylinder or two. But the car idled better once it warmed up, pretty weird no?

Was it cranking fast and just didn't wanna start? You may have a vacuum leak somewhere, when the engine is warm it can tolerate some unmeasured (by the MAF) air rushing in, but when it's cold it will be acting up. That would jive with the pinging sounds as well under load, the extra air from the vacuum leak is making her run somewhat lean, or at least screws enough with the ECM that it's not giving her enough fuel to compensate for the extra air.

[porschpow]

It cranked for longer then usual, before, I had to wait to crank it again, and then it started.

This most recent time, I cranked it and it had engaged the first time, but the idle was real low and extremely stumbly, after 5 -10 seconds it ran like it was misfiring, after doing that for a few seconds, it bounced back to running normally.

I did come across a smoke test for the vacuum leak, I guess I will try that

[His Royal Ghostliness]

Check the battery voltage after she's been sitting around for a while too, starting with a low battery does not make the ECM happy, it expects to see certain voltages out of its sensors but if the main system voltage is low to begin with the signal ones will be off as well.

[porschpow]

Ok, I should be seeing about 13-14 volts, no?

[sly]

13.6 - 14.4 depending on the health and quality of the alternator. If you see 12.6 or less, something's not right with the alternator probably.

[His Royal Ghostliness]

Yeah, this is with the engine running tho. Before you attempt starting the car, you should be seeing 12.x volts at the battery as she sits, like for example 12.5V would be a good battery.

[porschpow]

VOltage has come back normal,

However, I have an update

I have been told to check the plugs, as they may have been fouled. I will check the plugs, but it seems as though the car runs strong even with this issue This is why it's hard for me to believe that the plugs would be fouled...

But I will check them, it has been 50K almost..


BTW, I have noticed that when I run regular gas, the pinging and chattering is so much worse than when I use high test, especially when its under load and just shifted to OD.

[His Royal Ghostliness]

The change of octane causing it to ping worse under load sure sounds like you got too much timing on the ignition. This is an EDIS-8 car, right? How the heck do these time, crank and cam position sensors? Any DTCs present for either of those?

[porschpow]

don't know what EDIS-8?? this is 1997 Lincoln town car

I got no codes

[His Royal Ghostliness]

EDIS is the ignition system - like for example, "TFI" is what your box Towncar uses for ignition, that's the module on the distributor. EDIS obviously doesn't use a distributor, so it gets timed in a different manner from the older models. I'll see if I can dig something up for you regarding this later today.

[porschpow]

Yeah I know the old boxes you could mess with the timing, not these though

[His Royal Ghostliness]

Gotta be at least a way to check it tho... and I'm actually quite amazed no one has chimed in on that yet, considering the number of mod-motor people we get here.