Detonation problem 97 T-Bird with 4.6 V-8 (Full Version)

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Detonation problem 97 T-Bird with 4.6 V-8

  

doc99 -> Detonation problem 97 T-Bird with 4.6 V-8 (6/29/2005 2:43:48 PM)

Recently, the engine began "pinging" when shifting into high or overdrive, especialy with AC on. I tried using higher octane fuel inclding premium but it seems to have gotten worse. Just 2 days ago, the service engine light came on. Can't get into the garage until sometime next week so went to parts store and the code was read as "(fuel) system lean - bank2" The store rep said the code was coming from the o2 sensor meaning the one side of the engine was getting less fuel thna the other. Is that correct? Is there a process to diagnose the problem. Will geting the injectos cleaned resolve this? Any help would be appreciated.

  
Patrick -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (6/29/2005 2:58:34 PM)

i would try some injection cleaner first, but injectors CAN go bad.

doc99 -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/22/2005 10:25:54 AM)

Well, finally got the 'Bird into the shop and the code PO174 was still in the system. Ford has a list of 30 some repairs or checks to make for this code and the shop owner said it could cost $1,000 to check all of them and we still might not find out the cause. The scanner also reported that #2 spark plug had not fired 4,000 times, so they replaced that plug, and suggested that the plug wires might need to be replaced. Car has 62,000 miles on odometer.

They cleared the code and sent me on my way. The pinging has not improved any and the SES light came back on yesterday while I was on the road. Taking it back today to see if the same code is in the system. I have also ran 4-5 tanks of fuel with Lucas injector cleaner in since the trouble began.

Any suggestions?

cctxfish -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/22/2005 11:56:17 AM)

pakus, ramrod, anybody,
Doesn't this sound like the ignition is too advance. Isn't that caused by the load on the engine, measured by either the MAP, or MAF?
I've seen O2 sensors cause lean problems and set no code. They would linger within spec, but at the upper end (.9-.7V) causing lean condition but no pinging as I recall.

doc, You really need a scantool to watch different parameters. Bank2 lean, I'd watch o2b2, maf or map, fuel mpulse 1 & 2, spark advance, and TPS. Hard to say whats wrong with your bird. Helpful somebody seen this very thing and give you a better starting point.[:-]

pakus -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/22/2005 12:21:29 PM)

Catfish you are on the right track. The pid to monitor is the BARO pid. It is a calculated value made by the MAF. Here in Texas a good reading is around 150 to 158 hz. If it drops into the 140's range it will begin to run lean. Less hz means higher altitude which means less oxygen so the computer adds less fuel.

Ramrod48 -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/22/2005 10:32:58 PM)

YO !!!!! ( man that was a good nap ) Ah,, yea, Yea seems that summer time here in Florida the ole PINGER gets worst as the Temp climbs an the air burns your throat ( ever notice how nice your engine sounds when its raining an its like 70 degree's ), I gotta agree with the timing aspect. I have a very dear lady customer she's like 82, Drives this ole 87 Merc. Grand Marquie, a tad over 68,000 miles . She was by this week , Saying She thought the squirrels had gotten in Her motor ???,, Anyway Iam sure you guys have heard or possibly used " SEAFOAM ", well I ran a can of it through the motor, an yea it smoked like the dickens for a bit , Changed the plugs , no more pinging an got a pass 11 after reseting memory an test drive ,,So we sent her home. ,, My thinking is it possible had a lil bit of carbon build up, that led to the pinging

doc99 -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/23/2005 11:15:30 AM)

Thanks to everyone who replied - you guys lost me with some of that technical talk, like pid and hz, but I will print out your responses and share with the garage guy. He is a pretty decent mechanic and I trust him not to rape me.

I am not completely without mechanical experience but all of these computer controls make it so a shade tree can't fix anything anymore.

The pinging is worse with AC on which creates a load on the engine, and the engine temp seems to be higher than normal, but so far I can't tell if the temp increases come first or the detonation is causing it. The 'bird will run ok at highway speed so long as I can maintain throttle position. If I have to slow down for traffic, the spark knock will begin while trying, ever so gently, to accelerate. When in traffic, or at lower speeds, I turn off the OD to keep the trans from shifting into D or OD which increases the spark knock. I thought about the timing issue one of you mentioned, but there is no way to set that anymore, except by computer, is there?

Again, thanks to all for your help. If the additional info means anything, I'll be glad to listen. If / when I get it fixed I'll share the details in case anyone else has the same problem.

By the way, no one answered whether chnaging plug wires would be a good idea. What do you think?

cctxfish -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/23/2005 3:21:08 PM)

Its a good idea, but I don't think its going to fix problem. [&o]

doc99 -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/29/2005 11:11:41 AM)

I took the 'Bird back to the shop today and the same code PO134 was in the computer. The mechanic did find a small vacuum hose behind the intake which was cracked and replaced it. The pinging seems to have decreased, but the temperature was only 67 degrees instead of 105 and the AC wasn't on. I'm going to drive it some more to see if the code comes back.

How about this - one of the guys on another forum suggested putting in Ford OEM sparks plugs - he says this corrects the problem. Interestingly, the former owner replaced the plugs at 47,000 miles and I bought it at 53,000.

Have any of you guys heard of this fix?

cctxfish -> RE: Detonation problem 97 T-Bird with 4.6 V-8 (7/29/2005 12:20:13 PM)

Great let us know what you find.
As for the plug thing, can't hirt. As I remember Ford Contour 4L had 2 different plugs. My guess is that 2 cylinder shared one coil pack. As for as replacing plugs 50K or 100K, I don't on mine, I wait until something breaks, 137K on my Ranger orginal plugs as far as I know.[&:]

  

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