Pinging at light load

[MOOREMNY]

Hello everyone, I just bought a 1992 ranger sport 2.3 5 speed , 180 000 miles, i live in California and the truck won`t pass smog high hydro carbons, I changed the plugs and wires, needed it,sender and fuel pump, cleaned the MAF and air filter, good vac, egr works fine. here are my problems, first thing in the morning will start and run ruff for 4-5 secs and idle goes up run like a champ, also has pretty new IAC and O2 sensor, next while driving at light load it pings, step on the gas it goes away? Been on ranger forums for 2 days can`t find the the same symtoms or the cure. Thanks

 

[tbirdsps]

I too have a 92 equipped like yours. Mine only has 113,000 and the HC measures at 7 PPM at idle and 8 at 2500 rpm.

When you changed the plugs were any of the black? I'm thinking yes because it seems the engine is running rich. Have you read the codes? You may also consider a compression check. Since the 92 doesn't really have any adjustments to make the problem is almost certainly hardware. One thing to check is for vacuum leaks. Underneath the intake manifold there is a "L" shaped vacuum hose about 1/2" in outside diameter. It's pretty hard to see but when mine was leaking I had a rough idle on the first start in the morning like it was starving for fuel. I did not have any pinging though. I replaced it and the problem went away. A big vacuum leak will tend to cause the engine to run lean instead of rich but the computer could be compensating by scheduling more fuel because it senses lean due to the input from the O2 sensor. Do check that hose. I'm not sure where it leads to. I can't remember. Mine was completely full of cracks.

 

[MOOREMNY]

Thanks for the reply tbirdsps, plugs are lean, compression close to 115 across,vacuum steady at 17 lbs, idles smooth. thanks on the tip about the hose ,will check tonight.

 

[Original_Ranger84]

I would recommend seafoaming it and running the next up pump gas... The seafoam is poured into the engine and oil then you drive around with it for a while and it supposidly cleans up carbon deposits which is one of the main causes of pinging. the carbon deposits heat up and predetonate the fuel before the motor reach TDC. Also by running a higher octane fuel the detonation of the fuel will be higher so it should get rid of the pings.

Also run an injector cleaner through the fuel as well and see if it clears up any.

 

[DJ2.3]

If the egr is plugged with carbon buildup it could cause pinging. It doesn't throw any codes if it is plugged. You would have to pull the pipe off and check it. I ran into that with my 92 2.3.

 

[MOOREMNY]

I put vacuum to the egr and it want to stall i think that means it operational, I have never heard of seafoam , I have techron in the fuel tank now but next fill up I will try it. After driving it today, I notice that when cold it won`t ping or at more than 1/4 throtle, octane is not the problem, light load cruzing is, seems to be lean, i wish the ecm was obdII I`m stumped, I guess maybe replace the 02 sensor, even if it looks new. Thanks