View Full Version : knocking and pinging
Lately, my truck has been pining and what not, no matter the quality of fuel, brand or any additives that I add to it (seafoam, octane booster). It doesn't happen at low rpm's but usually the higher rpms when getting on the highway or passing, or just having some gas pedal fun. 87 octane and I promise it will ping all of the time, 89, and it starts doing higher in the range and with 92 or 93 it will do the same.
PLugs have about 5k on them as do the wires. I don't think they would be worn yet (I'll pull one this afternoon to check and see).
I have tried cleaning with Seafoam in the tank as well as using the brake booster line for direct injection. It gets regular checkups to boot.
Anything else I might be overlooking?
What year? There could be a couple of causes. One, if it is an older truck it may just need the timing checked, and set. Another posible cause is that it is running lean.
DOH! forgot to add the bit of info.
It's a 1998 'W' code with 101k on it, automatic.
Oh, well it isn't the timing, that is set by the computer, and is not adjustable.
I would try unpluging the maf, see if that changes anything.
I would also check the opertation of the egr, and make sure nothing is cloged there. The computer advances timing when the egr is active.
Have the o2's ever been changed? Those usualy fail rich, but i guess maybe they could fail lean? Also, any exhaust leaks, especialy around the headers/ypipe?
Joker2040
12-05-05, 04:13 PM
intake leaks??? I know my intake had slightly worked loose and when the engine torqued over it would suck in air.
Actually, my TB bonnet isn't exactly the most snug thing in the world. It's relatively easy to move or pull off. Maybe that is the culprit?
My o2 sensors are still stock as far as I know. I have never had them changed since I purchased it, and I don't think they were changed prior to me owning it.
as far as leaks, there aren't exhaust leaks that I know of. No holes or anything. I would need to have a much closer look at the header connections before I could say with any certainty.
I have the EGR limiter that I purchased from the s10planet store a couple of years ago. I could pull that off and see if it is becoming clogged.
Fix the tb bonnet first, i bet that is your culprit, it is probably letting unmetered air into the engine. As you increase the throttle the computer seems to rely more and more on the maf for calculating air intake, and fueling. Part throttle and idle are a mix of speed density, and maf operation. So, you would run leaner at wot than at part throttle. If this is the case unpluging the maf would eliminate the symptoms.
The egr limmiter will bring it closer to the edge of detonation, less egr, same timing. I ran fresh air into the egr port for a while, no pinging, so i think you should be ok on that side of things. The egr only works durring part throttle, and from the sounds of things it is doing it at higher throttle openings.
Yup, WOT is when it does.
Any ideas on getting a better fit on the bonnet without having to look around for a new one?
Is it a stock bonnet? Do you have any pics of your bonnet setup if it isn't stock?
It's a stock TB bonnet with a quasi home made intake. I haven't altered the bonnet in any way.
Sparky2263
12-05-05, 10:07 PM
I'm wondering if fuel pressure is falling off.
THA_BAD_ONE-0
12-05-05, 11:36 PM
Check iny thing that would retard the timing or would effect the computer to retard the timing. It could be lots. BUT IS THE SES LIGHT ON
THA_BAD_ONE-0
12-05-05, 11:44 PM
A How about doing a complete tune up on engine. It might not fix but wont hurt may help
The SES isn't coming on. I'm pretty damned quick to get it scanned if it ever does come on. Nothing is being caught by the ECM.
Any ideas on making my TB bonnet stay on tight?? Maybe a new bonnet??
Any ideas on making my TB bonnet stay on tight?? Maybe a new bonnet??
I am trying to remember how the stocker works. Is it installed properly? It looks like it has a clip on the front. Then a screw down hold down in the back, i have pictures if you don't know what i am talking about. I also have all of my stock stuff if you need any parts cheep.
Yep, it's clipped on the front of the TB and the nut is torqued down all of the way on the back side.
How much for that spare bonnet you have, Rat?
How much for that spare bonnet you have, Rat?
Don't know, it is back at my house, i won't be home until next friday. Name a price, $30+shipping?, make an offer. I have all of the stock intake ducting, or if you just want part of it that is just fine.
Are you sure that is the problem though? Are there any gaskets or anything up there? Did you try unpluging the maf? If unpluging the maf doesn't cause any change then it isn't the bonnet. Also, if you run a k&n oiled style filter it tends to get the maf dirty, and it may need cleaning.
You say the nut is torqued down at the back, could it be too tight causing the front to come up? Maybe try bending the front clip down slightly to give it a little better seal.
I'll try adjusting the clip on the front. The MAF is clean. I cleaned a couple of weeks ago and the filter I have now is a steel mesh one that doesn't need the oil on it.
I just thought of something too, but if it were a bad bonnet seal, wouldn't throw a code for the MAP sensor???
No, it probably wouldn't throw a code.
Unplug the maf, and see if it fixes anything.
Well unplugging the MAF didn't do anything for it.
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