CTV

Sorry to another of these threads, but haven't found the solution in search. Got a 1992 v6 pickup that ping occasionally in high load/throttle, and when letting off from higher throttle. Set timing to 10 from 13 how I bought it, helped alot, but any less its terrible power. New NGK's, cap/rotor, radiator, TPS set, EGR and modular work with good vacuum, new air and fuel filter, seafoam treatment, O2 base ohms are good, coil is a bit high primary resistance but rest is good, base AFM is good.. timing also bounces at 8-10 idling. It also runs on the hotter half of the gauge. Is there anything likely for this issue? It's jerkier but no ping when warming up.

MudHippy

Hmm...let me think...

• 3VZEs don't usually ping much, or ever, unless there's something pretty drastically wrong.
  
• 10° is stock initial ignition timing, so any lower would be bad for power(not sure how much less there is on yours, there's 0° less on mine, it won't go any lower than 10°).
  
• Basically every other potential cause has been looked at.
  
• Timing bounces @ 8-10° idling, which is optimal without the check connectors jumped BTW.
  
• Wait...you say it runs on the hotter half of the gauge and no ping while warming up? Mine almost never gets up to or above the middle of the gauge. It takes some doin' anyway, let me tell ya. Gotta run it WAY hard even on a hot day...even then it don't hardly ping(it almost never does period, under any conditions). And I've got the initial timing set at ~23° BTDC. Even with 91 octane, that's decent amount of base ignition timing advance more than stock. And it works out ping free for me like that.

Buddy...I think you've got a cooling system problem, possibly among other things. Don't know for sure what, but it all points to it. The gauge reading too high for normal driving and the excessive pinging caused by it. Some kind of coolant flow blockage/inefficiency is likely going on in there somewhere. That's where I'd start lookin'.

Good luck!

CTV

U know I had a suspicion... the bottom end power is surgy with 10 degrees tho and butter at 8-9ish, I'm not exact its too bounce, and it is jumped I didn't try it unjumped
I can't find a t-stat cooler than 180 but one of my pulleys is squeaky so maybe the pump.
There's beige crud on the coolant overflow straw but oil and coolant are clean and no rad bubbles so maybe it wasn't cleaned when it was HG recalled several yrs ago.

The MAN

replace the radiator and get an OEM thermostat
make sure the radiator cap is also new and good
if the fan clutch is original, service or replace it

try running colder spark plugs, it will help a little with preignition

CTV

Ah bigger plugs and rad are already new lol... is there a way to test the stat? Rather leave it if I can help ir

CTV

Er bugger even, gotta love auto-correct... does anyone know if the erratic idle timing is normal? I can't set a definitive base timing with it

MudHippy

Yes, like I said, it is without the check connectors jumped. Or if the idle speed is bouncing around too. You won't be able to set the timing very accurately at all if it isn't running well at idle(as in steadily @ the correct speed of 800 rpm +/- 50).

1. I can't find a cooler one either, and I personally wouldn't run it if I could(for obvious reasons).
2. It may have something to do with the water pump, but it's probably one of the idler pulleys that's squeaking.
3. You could try flushing the system anyways, if you haven't yet. That might help.

1. Cooler plugs I wouldn't recommend just yet. You might run into some fouling problems with those.
2. Yes indeedy-do, there's a way to test a t-stat.http://personal.utulsa.edu/~nathan-b...10thermost.pdf

CTV

Cool thanks, I noticed its worst at high speed cruise today, and premium didn't help with the issue

CTV

As well, I hit the highway before it was fully warm today, the gauge stayed in the low half like it used to but still pinged on slight inclines in the higher cruise rpm's especially, with 91 octane, and once i slowed in town and the temp went up higher it never dropped once back cruising... I know I'm due for a timing belt replacement, but could that possibly cause this? Maybe worn mech. advance springs, leak in the ISR system, pcv (not sure why it has one with a direct line to the rocker cover in front of the TB) I duno I'm reaching here.
Thanks for the replies so far, I'll keep tinkering.

CTV

Yup, no fan clutch... takes very little to stop it and rpm's don't make the fan try to spin any harder. But I'm at 8 deg. base jumped and still there when only part warm... t-stat and coolant coming but if not that, lost...

CTV

Also, what are the 2 large hoses going to the intake silencer? Both were loose and only the large one sucks on decel

CTV

New job takin all my time up haven't done a lot these days but ping is starting to come back like when I.first got it... Nothin changed so I got impatient, ran 91 octane with bottle of octane boost and it improved significantly this time... Then gas shot up 20% in price so back to reg and bad ping... Tried with tps unplugged, idled way high but very little ping and huge performance boost, also ran significantly cooler both ways. Ive noticed the temp fluctuates a lot on reg while cruising and has intermittent poor acceleration stoplight to stoplight.