detonation

tmz93sc

Registered User
a while back i posted that i was getting some pinging with my 93 sc. and it was suggested that i put my stock maf on , as i was running a 76 mm c/l , anyways i hadnt noticed any pinging until yesterday i had to pass a tractor trailer to get off my exit and noticed it bigtime. now this has me a bit worried because i just had the hg done this past summer. my mods are s-port late model , mp plenum 75mm throttle body, it has stock intake and stock maf. i never bothered to get it tuned for this set up. so my ? is am i asking for my hg to blow again. i can get up to about 12-13 pnds of boost and not hear it other times i can only go part throttle and hear it. i always use shell 93 octane , and the car doesnt have any vacum leaks she runs smooth.
 
interesting the knock sensor can pull out up to 8 degrees so thats unlikely youd get knock

a simple mail order chip can fix that, ~$100 for forum members w/ stockish setups
 
If you have a bit of blowby it is posible the oil from the PVC system is puddling in the IC/intake and when boost starts to kick in the motor gulps alot of oil. I was having this problem and oil is very low in octain rating. Took along time to figure out why sometimes i could beat the hell out of the car and other times just a little boost would cause some pinging.
And yes get a tune from Michael.
 
If you have a bit of blowby it is posible the oil from the PVC system is puddling in the IC/intake and when boost starts to kick in the motor gulps alot of oil. I was having this problem and oil is very low in octain rating. Took along time to figure out why sometimes i could beat the hell out of the car and other times just a little boost would cause some pinging.
And yes get a tune from Michael.

if im getting oil blowby how would i fix it ? i remember putting a new pvc on last year. the old motorcraft seemed to still work but i just assumed to replace it since it was never before
 
You would need a oil separator or catch can. The PCV system must remain a closed system so stay away from any canister with a breather filter. Also most cheap e-bay units have no filtering media inside and probably very ineffective. Some just use a oil water separator for an air compressor but typically their volume of oil they can hold is pretty low. It would go inline between the PCV filter and the inlet plenum.
 
Sounds to me like it's your throttle position to go open loop. It can be adjusted but be careful because if you go too far gas mileage will suffer.
 
Sounds to me like it's your throttle position to go open loop. It can be adjusted but be careful because if you go too far gas mileage will suffer.

older ecus use load for fuel not tp, 99 was the change year on ford cars
they do have a tp ol scalar though

however, a leaner engine can tolerate more timing without audible detonation due to lower cylinder pressure, this is even more prominent on our sc engines as they have a very high bsfc as compared to similar engines

have u tried getting the engine warm and sucking a bottle of water through a small vac line? this will steam clean the combustion chamber and remove carbon build up, probably wont resolve your pinging issues but will clean out any oil contamination in the cylinders

u should check that knock sensor too be sure its got a good connection
 
check fuel pressure as well

This is where I would start. If you haven't changed your fuel pump, it's way overdue. Check fuel pressure under boost. Should be 39+ whatever your boost is and hold steady at all rpms.

Another thing is that if the engine runs too cool the knock sensor won't work. Min ECT for knock sensor is 186 deg. If you have your engine running cool for some reason then the knock sensor is disabled. It could also be unplugged or non-functional.
 
This is where I would start. If you haven't changed your fuel pump, it's way overdue. Check fuel pressure under boost. Should be 39+ whatever your boost is and hold steady at all rpms.

Another thing is that if the engine runs too cool the knock sensor won't work. Min ECT for knock sensor is 186 deg. If you have your engine running cool for some reason then the knock sensor is disabled. It could also be unplugged or non-functional.

the fuel pump has never been changed probably a good idea. the engine always gets to normal operating temp. i might try putting the old pcv back on and see what happens? i also get a slight hesitation when cold seems to smooth out after a couple of miles. knock sensor is plugged in
 
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