TrimDrip

I had a detonation problem with a supercharged car. No codes ever after I fixed it the first time before the supercharger. Had it tuned. All fuel componets were upgraded and so was the maf with all new parts. Turned out the ac compressor bearing was starting to go bad. Never made a racket until it finally locked up. Granted the car did idle rough at times unless I took the belt off.

So I guess it wouldn't hurt to take the belt off and see what it does. Just don't run it hot.

Also, you sure you are not hearing a lifter? They make a bit of racket under load when they start to go.

Canary94GT

Quite sure this is pinging based on what I've heard in other cars. Car only has 80,000 miles or so.

Sigh, it appears so many factors can contribute to pinging.

For sure my next step is to retard the timing a couple more degrees and check my fuel pressure. If neither of those lead me anywhere, I will look further, such as the ac compressor >.<

Thanks for posting man, the more help the better

TrimDrip

Your car shouldn't ping at ten or eight degrees. If you want to totally eliminate that as the problem, take the spout connector out. The computer adds timing. With the spout out, it doesn't advance timing any.

When your tank is full the fuel pump is submerged in gas. At a quarter tank, it is not. That is probably why it makes a different noise. Your fuel pump also runs cooler when submerged in gas.

Canary94GT

Yeah, but this time the tank was 1/2 full

TrimDrip

yours is loud but, no louder than mine. I have an upgraded pump and it can be heard with a recorder from 20 feet away. If it is different, i guess it could be getting old. I have heard some old chevrolets trucks get really loud.

Anyways, advanced sales a fuel pressure tester made by Actron. I think it was around 20 bucks. Not sure how you will test is going up the road though unless you tape it to the dash.

One thing about running out of fuel is your rpm won't turn up high. When I bought my car it would max out at 5200 rpm. I thought it still had an air silencer on it or something. Changed the fuel filter and now it turns until it hits the limiter with ease.

What I would do and most other mechanics would do is take out your plugs and look at them. If they are extremely white, you are missing some fuel for whatever reason.

Canary94GT

Hey, thanks Trim.

Pulled my plugs and 1) Noticed they looked pretty clean, maybe a little grayish-white (might be because they were changed <3000 miles ago and are platinum) and 2) that the plug gap was set incorrectly to around .042 rather than .052. I removed the plugs to fix that and figured while they are out I may as well try a colder plug, so I bought some copper Autolite 24's (one step colder), and gapped them to .052.

The mechanic that last did the plugs must have been an idiot - he used no anti-seize and must have reefed them down to >25 ft-lbs, cause it took A LOT of force to get them to budge, not to mention he gapped them incorrectly.

I also checked if the harmonic balancer had spun by attempting to find TDC, using a long screwdriver through the #1 spark plug hole. The balancer appeared to be within 2* for sure.

After changing the plugs, I took it for a drive and noticed the swap didn't fix the issue, and may have made it slightly worse by pinging not just when under load anymore (was it because I increased the plug gap?).

I went ahead and bumped the timing down from 8* to 6*, and it seemed to help a bit but not completely - not sure if I want to lower it anymore. But it didn't seem to noticeably hurt my performance.

I still want to check the fuel pressure, but have not been able to borrow/buy a gauge yet, might be able to on Monday. I have a mechanical oil pressure gauge, but I take it that won't work?

TrimDrip

Yeah, running a platinum was a bad move on the mechanics part I think.

I have never tried an oil pressure gauge on a fuel line before. You would still need a way to screw it in to the valve on the fuel line to get it to work.

scottybaccus

You are probably getting some carbon build up in the combustion chamber and on the piston tops as you approach 90k. It raises the compression ratio unpredictably and noticably. This happens in every engine eventuallly, but varies with usage, fuel, maintenance, etc. Problems with carbon in the EGR valve and Idle Air Control port usually start cropping up at the same time.
Old school trick for getting it out of there is to trickle water into the intake at a high idle, 2000 rpm or so. The more water you put it, the higher you'll need to hold the idle.
Water does not compress, so it effectively knocks the carbon loose to be blown out the exhaust valve. I've had tremedous results on several older engines this way. On an old carbed engine, we used to follow that with a trickle of auto trans fluid for the sake of the valve seats and such, but that's really unnecessary on newer engines with hardened seats.
Short of disassembly, this is about all you can do to get carbon out. There are a dozen different procedures in the factory service manuals for getting it out of the intake, a BIG problem on Ford's 2.3-2.5 Lima motors, but not much short of tearing it down to address carbon in the cylinders.

Canary94GT

Checked the fuel pressure with a real gauge and at idle it's running 32 psi with vacuum and 40 psi without vacuum, and with the ignition off it holds 35-40 psi.

So to recap:

- Running 89 octane currently (running 91 doesn't seem to help any.. also note: contains up to 10% ethanol)
- Replaced EGR system
- Cleaned MAF sensor
- Replaced ACT sensor
- Replaced ECT sensor
- Changed platinum autolite 25 plugs to copper autolite 24's (one step colder) and gapped them correctly (were gapped at .042 rather than .052)
- Replaced cap and rotor (wires are relatively new)
- Ran a couple rounds of seafoam through a vacuum line (didn't get much smoke)
- Retarded timing to 6*
- Checked and found balancer is NOT spun
- Checked fuel pressure

Still have pinging.

What should I do now?

mjr46

I do an induction clean at the Throttle body, we use a pressurized spray unit from BG, mists it in and effectively hits all cylinders, drawing in through a vaccum line can sometimes pull it to the closest runner.