help me fix my knocking problem

JimTMich · Sep 7, 2004

I've done the usual with no change in my pinging situation.
113,000 95 GTS manual
replaced the ect, intake air temp, cap, rotor, plugs, wires, fuel filter, timing set at 7* with 93 octane to avoid pinging.
fuel pressure is 38psi hose off.
160* thermostat
I've gone over the motor looking for vac leaks and found none.
I've even sea foamed the motor by pulling the vac line at the break booster and sucking in half a can, letting it sit 5 minutes and starting it back up (no smoke, no nothing).
This think has been pinging for years, slowly getting worse.
It only pings once the motor has warmed up and it pings at wot above 3500 when I try to add timing or when I reduce octane it even pings at part throttle.
What do I check next?
I still have the stock maf (I've cleaned it a few times)
should I try cooler plugs?
should I get an afpr and bump it up a little or will the computer re-write the WOT fuel table?
I have no codes in the computer.
Could the cats be plugging up, Haynes manual has that as a possible cause of pinging?
Thanks!

jetuomi · Sep 7, 2004

do you have stock heads? if so, I would say there is nothing you can do about it.. carbon buildup has increased your compression ratio and that's it.. I went to aluminum heads and the problem was gone (didn't have to change ECT, ACT, etc).. I know that's not the answer you're looking for but that's how 94 cars seem to be..

94TURBO5 O · Sep 7, 2004

Locked timing in hot weather is the key , IMO. Take out the spout and set your timing to 20 or as high as you can get it w/o pinging and leave the spout out until the weather cools down. Then you can try to set the timing back at 10 degrees and put your spout back in. I run locked timing w/o detonation and this may help you also.

mystang94gt · Sep 7, 2004

JimTMich said:
Could the cats be plugging up, Haynes manual has that as a possible cause of pinging?
Thanks!

Has anyone ever experienced pinging because of a clogged cat? One of mine is clogged right now and I cant keep my car from pinging. If that was the problem it would be an easy fix.

mo_dingo · Sep 7, 2004

Have you hooked up a vacuum gauge?

The next step is replacing the MAF sensor, do some serious head/piston cleaning. I mean remove the heads, and grind the carbon out of the combustion chambers. Then do the same to the piston tops. Make sure the cc's are extremely smooth, and the same with the pistons. This should prevent carbon from building up in the future.

I know it's excessive, but it's the only thing I can think of. You have tried everything else.

A guy I know installed a Tweecer, and even though he cleaned his MAF, the Tweecer datalogs showed the MAF being 13% (I think) off of normal. After he fixed it, his problem went away. So maybe a new MAF sensor would fix the problem.

You could always go to autozone, and get it, replace it, and try it out. If it doesn't work, then bring it back and say it didn't fit.
Scott

stangla2 · Sep 7, 2004

If you have the stock heads, the valve springs only last about 100k and you get pinging alot!!!! i rebuilt my engine at 89k... so good luck and have fun rebuilt your engine

rapidsft · Sep 8, 2004

same problem

man i have the exact same problem you have. I'm still trying to figure out what is wrong, bloody 94-95 cars have the worst EEIV settings imaginable.

stang_gt_1994 · Sep 8, 2004

stangla2 said:
If you have the stock heads, the valve springs only last about 100k and you get pinging alot!!!! i rebuilt my engine at 89k... so good luck and have fun rebuilt your engine

Wow I have 191K miles with no rebuild. The valve covers havent been off for Gods sake. I do not see why valve springs would cause you to detonate. Now they would cause valve float in the upper RPM's.

JimTMich · Sep 8, 2004

Assuming it's the maf, I could either upgrade, auto zone or could I buy an adjustable fuel pressure regulator and bump up the fuel pressure? the o2 sensors would help the computer re-tune for closed loop and then I would have the extra fuel at WOT?

If it's carbon buildup, that's all the excuse I need to get some new heads.... but don't want to replace heads when it was the maf. It's hard to get a big block of time to do a head swap.

stangman1 · Sep 8, 2004

pinging

The spout connector is bad and the spout, I have same same prob and
I replaced every thing and i got fed up and took it to the dealer and they
hooked it up to the dyno and that was it and i got it back and no more pinging. try it it might save some $$$$

mystang94gt · Sep 8, 2004

stangman1 said:
The spout connector is bad and the spout, I have same same prob and
I replaced every thing and i got fed up and took it to the dealer and they
hooked it up to the dyno and that was it and i got it back and no more pinging. try it it might save some $$$$

Stangman, How much did it run you to have them check what the prob is? I would like to take it to the dealer and have them diagnose the prob I am having so I can take it home and fix what is wrong instead of replacing everything I can think of like i have been. if its cheap it may be an option.

stang_gt_1994 · Sep 8, 2004

stangman1 said:
The spout connector is bad and the spout, I have same same prob and
I replaced every thing and i got fed up and took it to the dealer and they
hooked it up to the dyno and that was it and i got it back and no more pinging. try it it might save some $$$$

When you say bad do you mean it would not close the EST wire or what.

final5-0 · Sep 8, 2004

rapidsft said:
man i have the exact same problem you have. I'm still trying to figure out what is wrong, bloody 94-95 cars have the worst EEIV settings imaginable.

BINGO!

Give this man a cigar!

The GT cal file is very lean & has an aggressive spark table as well.

You don't hear the Cobra boys crying about the ping thing cause their fuel table is a bit fatter and the spark table is softer than the GT cal file.

Later
Grady

stangman1 · Sep 8, 2004

pinging

I paid like 180.00 and they fixed it and it was th est wiring and the spout
connector now my car does not ping at all. But if the dealer does it you
will want to advance the timing when you get it back.

stangman1 · Sep 8, 2004

pinging

Ok this is what the service invoice said they did (REPAIR WIRING TO TFI MODULE REPLACE SPOUT CONNECTOR) PART #FMC*E53Z 14489 C
PARTS 3.88
LABOR 156.00
And this fixed it
Ford is expensive some times but they have the right computers to dyno
and scan these issuses.I took it to other shops they blam it on carbon build
out and that is not the case. my friend has like 300,000 on his 87 5.0
and runs very good.

stang_gt_1994 · Sep 9, 2004

stangman1 said:
Ok this is what the service invoice said they did (REPAIR WIRING TO TFI MODULE REPLACE SPOUT CONNECTOR) PART #FMC*E53Z 14489 C
PARTS 3.88
LABOR 156.00
And this fixed it
Ford is expensive some times but they have the right computers to dyno
and scan these issuses.I took it to other shops they blam it on carbon build
out and that is not the case. my friend has like 300,000 on his 87 5.0
and runs very good.

LOL, so your SPOUT was broken? Its caused the EST wire to be open all the time, thus causing the car to run on base timing all the time. Doesent seem like it would cause a issue to me, just a decrease in performance, and not a ping issue. I think you got ripped my man.

stang_gt_1994 · Sep 9, 2004

JimTMich said:
I've done the usual with no change in my pinging situation.
113,000 95 GTS manual
replaced the ect, intake air temp, cap, rotor, plugs, wires, fuel filter, timing set at 7* with 93 octane to avoid pinging.
fuel pressure is 38psi hose off.
160* thermostat
I've gone over the motor looking for vac leaks and found none.
I've even sea foamed the motor by pulling the vac line at the break booster and sucking in half a can, letting it sit 5 minutes and starting it back up (no smoke, no nothing).
This think has been pinging for years, slowly getting worse.
It only pings once the motor has warmed up and it pings at wot above 3500 when I try to add timing or when I reduce octane it even pings at part throttle.
What do I check next?
I still have the stock maf (I've cleaned it a few times)
should I try cooler plugs?
should I get an afpr and bump it up a little or will the computer re-write the WOT fuel table?
I have no codes in the computer.
Could the cats be plugging up, Haynes manual has that as a possible cause of pinging?
Thanks!

Try this out man. First off do you run a K&N filter, or any aftermarket filter that has oil on it to coat the hot wire on the MAF? If yes then the hot wire will become coated, thus causing the meter to send a signal to the PCM at idle that more air is flowing then it really is (causing a rich condition). But at cruising or load the meter will tell the PCM a false reading that less air is coming in but really it is more air, thus causing a lean condition. Lean means pinging. So you say you cleaned the MAF many times? So? Cleaning it is just a temp fix that doesent always work. To test the MAF you will need to do a snap voltage test. Get a DMM (digital multi-meter) and put it on the min. max volt scale(DC). Back probe the MAF at the output and ground pins and have the engine running and snap the throttle wide open and release. If the Max volts do not go past 3 volts then the MAF is bad. Simple as that.

JimTMich · Sep 9, 2004

final5-0 said:
BINGO!

Give this man a cigar!

The GT cal file is very lean & has an aggressive spark table as well.

You don't hear the Cobra boys crying about the ping thing cause their fuel table is a bit fatter and the spark table is softer than the GT cal file.

Later
Grady

did you use the cobra files as your base when you tweecer ed your car? or can't you do that. been thinking about getting a tweecer, heads, cam... but wanted to get this knocking thing figured out first.

JimTMich · Sep 9, 2004

stang_gt_1994 said:
Try this out man. First off do you run a K&N filter, or any aftermarket filter that has oil on it to coat the hot wire on the MAF? If yes then the hot wire will become coated, thus causing the meter to send a signal to the PCM at idle that more air is flowing then it really is (causing a rich condition). But at cruising or load the meter will tell the PCM a false reading that less air is coming in but really it is more air, thus causing a lean condition. Lean means pinging. So you say you cleaned the MAF many times? So? Cleaning it is just a temp fix that doesent always work. To test the MAF you will need to do a snap voltage test. Get a DMM (digital multi-meter) and put it on the min. max volt scale(DC). Back probe the MAF at the output and ground pins and have the engine running and snap the throttle wide open and release. If the Max volts do not go past 3 volts then the MAF is bad. Simple as that.

I'll give that a try!

stangman1 · Sep 9, 2004

pinging

I did that to my car and it stiil pinged

help me fix my knocking problem

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