cannot solve this for nuthin'

[xxninja]

man guys i cannot solve this problem with my car that i been having all summer with my national
well i cannot figure out why when i step on the gas and the engine goes into load, the car is making a metal pinging sound even at 5 psi of boost !
now i changed the wires and plugs(ac73ts) and ignition system 3 (caspers, wells)different times and it wont solve it, i got a new o2, and it is around 780 on the scanmaster even when it does it.
im not throwing any codes and i have have good voltage and vacuum.
i went so far as to replace the headgaskets , maf, get a new fuel pump n hotwire it and buy new injectors with a chip to match

my only last ideas could be the cam sensor,egr , or possibly timing chain. whats the chances a bad cam sensor could be that out of time to make a metal pinging sound.
i know alot of people seem to think it's boost related, but it happens at 2-5 pounds of boost just putting load on the engine and i am not rich or lean on the 02s. i run 93 or 94 octance always.

it seems to run fine just running around town, but when u go to get on the boost it starts to do it.
i dont understand this at all, its a summer car with 60k original on it, stock turbo and just has a cold air kit on it, adj regulator & wastegate

this is some of my scanmaster stats........
car idles at 700 smoothly
temp : 170
no codes what so ever
o2 : 780 as high at 802
maf : 8 at idle
tps : .42 / iac :20 at idle

i just wonder if any1 had a little insight or an idea or what 2 try
or look at .i'd appreciate any comments
thanx guys

 

[Boost231]

thats a typo on the plugs right (ac73ts). A metal pinging sound is probably detonation. What does your scan tool say for knock count?

 

[xxninja]

yea it was a typo, i got the ones on gnttype.org

well as for knock i swear it has never even registered anything
im wondering if it even works at all, ima have to try the socket extension tap test in the mornin for sure

well when u say that a car pings do to detonation, does that usually mean to much fuel? or not enough
ima borrow my friends fp guage tomorrow and re check it, but what do u think is a standard fuel pressure for a hot air national?
last time i checked mine was 36-38 sumwhere round there, the scanmaster in generally round 780- low 800s

could an exhaust leak on the cross pipe between the headers cause a crackling /pinging sound? im wondering if that coudl be a cause for detonation as well????

i know there is prbly a thousand posts for detonation on here
but what are some main causes of it, or maybe u can give me a link to a web page with some ideas

ive changed the ignition system twice and i think whatever is causing it has to be some stupid overlooked thing that i did not think about
well keep the ideas coming =)

 

[YNOVATE]

detonation I believe is when the gas burns too early and not in the combustion chamber. the higher the octane the more resistance there is to detonation because high octane fuel needs a direct spark to ignite. usually a detonation is loud and blows head gaskets...if it would be a small "pinging" noise then I think Boost231 could be on the right track with the plugs. what do you have them gapped to? Plugs may be burning too hot. see how a mix of a 50/50 tank with 100 and 93 works out. or if your comfortable enough try straight 100.

its probably a pretty vague definition of detonation but I think I'm pretty close.

 

[JasonB]

Try YNOVATES idea it worked for me. The chip I put in after I did my ECM conversion was causeing detonation at 5 - 10 psi depending on how hot it is outside and if the car was around 180-190 DEG it would knock in 2nd just trying to pick my speed back up. Sombody said my chip probably has to high of timing in it. I mix 3 gallons of 110 to a tank of 92 and I have very little if any knock in 3rd gear, and I can run 15 psi.

 

[xxninja]

well i have my pluggs gapped at 33 or 34, i thought it might cure up a lil detonation
do u think that is too tight?
well i run a jay carter chip after my ecm swap
wonder if this chip just has 2 much timing
i also has a thrasher in the garage i could try, but if i recall right.... it did do the same thing

so maybe i shoudl try to gap to 35, and try some higher octane
but there needs to be a cure cuz $3.60 a gallon isnt cheap lol

any1 have any lower timing chips they could reccomend
so far it has just been thraser and jaycarter

thanx your input guys
ill report back once i cant get time to go to the gas station


thanx

 

[YNOVATE]

I agree man....there's no way I can afford $3.60/gallon right now.

I've heard of but have never tried that you can mix up xylene/toluene and marvles mystery oil then add it to gas to get a high octane count for fractions of the cost. the marvel myster oil is added because xylene is such a "dry" burning fuel that you'll ruin your seals if you run it without the oil.

you can probably do a search for either xylene or toluene and find a previous thread for the mixing directions.

try the bigger gap in the plugs and the higher octane fuel either by buying it from the pump or mixing it up.

 

[TurboBuickSix]

What you need to do is drive the car with a fuel pressure gauge attached and see if you have the pressure going up with boost.There needs to be a certain amount of pressure increase for each psi of boost,if it is not there then the regulator could be at fault as well as the pump.I see the o2's are good but do this just to be sure.Did you do the knock sensor test? If you have a spare known good ecm try that.Try tapping lightly on the MAF and see what happens.

EDIT:I forgot to ask how old the motor is,could be carbon buildup.

 

[xxninja]

well i just got a new fuel regulator from kirbans along with a knock sensor and a better fp guage

my motor has 60K on it, but during winter i had the heads cleaned up and the seals & springs replaced

i was thinkin maybe my regulator was shot, it seems everytime i go to turn these adjustable regs down lower then 36 they break on me, i thought they were sposed to go to 30 ???
when i shut the car off it drops to about 20 or so, but doesnt go lower for a while later, is that common? i dont think i have a fuel problem, i do have a hotwired walbro 340, should be way more then sufficient for a stock turbo

well once it stops raining im gonna re-gap my plugs and try the regulator and put the knock sensor in, it is located just behind the back of the intake correct?? like straight down from the middle of the firewall correct?

well thanx for the input, ill give it a try, but any comments u may have, throw uhm my way !


thanx guys

 

[TurboBuickSix]

You are correct about the location of the knock sensor.When you do this stuff remeber to do one thing at a time testing the car in between parts changes,that is one of the rules you will hear alot on this board.