Pinging?

[tiger]

Hello, lately I have been noticing some rattling noise at low rpm's.. (it stops rattling at about 2500rpms.only under load, I guess... it has been doing this for about a week or so) My friend tells me its detination.. I told him that detination is really loud (at least that's what I hear). He thinks my timing is off and it's causing it.. I searched about it but didn't really find the answers i needed. Pinging can come from bad gas, right? I am guilty of using 87 gas., the crappy kind. Please help, I don't want my engine to break down.

[Ni2s4s0aSnX]

Could the timing chain guides.

[tiger]

oh, well another thing i forgot to mention is the fact that I don't have a knock sensor in.. i took it off... would that cause my car to run crappy? Also I went to the parts store and got a timing light... I used it and saw that my timing was way way off... to the right of 20btdc about 1 inch.. so I retarded it, i think.. to where it was sitting on the last white dot (the dot lines up with the thing that's poking out) that's 20degrees btdc right? It still makes the noise a little bit, not as much as it did before though.. i think my plugs are bad.

[jr.]

I just got back from the shop with what sounds like about the same problem, the mechanic checked everything and told me it looked fine, then he asked me when was the last time I changed my fuel filter, so I told him I had not changed it since I got the truck brand new in 96 so he replaced it and the problem went away. He said it was starving the engine under load. Never heard of the fuel filter causing that kind of problem but it worked for me. Hope this helps.

[tiger]

wow that's wierd... my filter is practically brand new. I know my fuel pump works.. they either work or don't work so I know it's good. I was just outside playing with the timing light and adjusting the idle and I heard the rattle at low idle... I squatted down and listened.. it sounded like it came from the transmission ... I said.. nah, couldn't be.. then i noticed the catalytic converter. The exhaust system that the previous owner put on the car is total crap and it rattles all the time.. I guess the heat shield or something in that area is rattling ... i have scraped the cat a few times pretty hard cause my car is rally low. When I first looked at my timing.. well... i'll draw a picture of it so you can see what i'm talking about... tell me if this is too advanced or too retarded... ok?

[jr.]

I couldn't tell you that's why my truck was at the shop. If you cant get any help on here try nissanminis.com it's a Nissan mini truck web site go to the performance section, just tell them what you got and what the problem is they'll be someone on there who can help you especially with the pics you have. Should'nt be a problem the engines in the Nissan pu and the 240 are the same basically.

[s13sr20chris]

yes, red dot is too advanced and where it is now is too retarded.

you want 15 to 20 degrees. thats with engine warmed up and tps unplugged.

detonation is not loud. it has a distinct sound that you would probably recognise if it was pointed out. it an irregular pattern of jingly pinging type sounds.

if your noise goes away above 2500 then it is more likely not detonation. however with the timing way advanced you prob were getting some anyway.

[tiger]

hey, I was fixing the timing yesterday.. I unplugged the tps... I don't know what I did but I set the timing with the tps off...

the idle screw... which way is increase idle speed and which way is decrease idle speed? Do you turn it very slow, or what? my distributor is all the way advanced. and it's sitting at about 21degrees btdc. Is that right? also i dont think I can get it at 15 degrees btdc cause I cant move the dizzy and more forward. I thought being closer to TDC would be more advanced and further away would be retarded.

[s13sr20chris]

you cant turn it any farther? try turning the other way. if you cant go any farther but need to then you have some work to do.

sohc-you have to drop the oil pump to fix

dohc-timing chain is jumped

i believe counterclockwise is to raise idle.

[tiger]

oh i thought it would be cool to just leave it at about 18d btdc. For some reason when I unplug the tps and try to adjust idle it wont lower it more than 1.2k rpm, it will raise it up higher but I cant set it that low with the tps unplugged (650)