Minimum fuel pressure
#11
04-11-2018, 07:20 AM
Also, check the upstream O2 sensor connector 1)is it plugged in, 2)is it clean and 3)do a circuit trace to the ECM of the wires if nothing else is obvious. Trims are your problem here. That's why your sputtering n stalling. If the negative trim continues, it might be a bad O2 sensor, but that's an educated guess based on snapshot data. How's your air filter...clean/new?
#12
04-11-2018, 07:43 AM
#13
04-11-2018, 07:55 AM
#14
04-11-2018, 02:40 PM
Ok first off. When you say circuit trace you mean check the voltage at the front o2 on a cold start until it warms up. Like the book describes? It says voltage on cold should be 0.1 to 0.2 volts until warm which should then be 0.1 to 0.9 volts.
I have had no electrical problems other than an issue I had with my o2 sensors a few months back. Which heyyou had helped me come to a conclusion that it didn’t like the particular brand I was using an seems to like the Bosch after I had gotten around to it. I am thinking this may be relatedness in some way. Maybe if you have some time you can over the thread an see if either of these issues seem to go together at all. The thread is labeled “inconsistent stalling issue”.
I have pulled my plugs I will upload a pic because I’m not to positive on the condition of these it seems it would be fuel fouling but I’ll let you decide.
In the process I have ruined a plug wire so any further testing will have to wait until a trip to auto parts store. I do have the ability to produce data while driving as soon as I get it going again I will do so
i appreciate the help on this issue
#15
04-11-2018, 02:46 PM
also when I was pulling these plugs I had gotten a really strong smell of fuel.
Which I thought was odd never really got the fuel smell like that pulling plugs.
One more thing the fuel consumption is just literally in the toilet since I installed this engine 3 years ago. I get about 230-240 a tank. Before the old engine took a crap I was able to pull 320-330 a tank
well thought I’d add that in there
Which I thought was odd never really got the fuel smell like that pulling plugs.
One more thing the fuel consumption is just literally in the toilet since I installed this engine 3 years ago. I get about 230-240 a tank. Before the old engine took a crap I was able to pull 320-330 a tank
well thought I’d add that in there
#16
04-11-2018, 03:10 PM
what r the specs on this engine opposed to the old one...what year, size, cam, crank, pistons, compression ratio, heads...that kinda thing. High fuel usage is helpful info to know, considering the heavy duty leaning of the short term fuel trims. What brand of plugs are those? Nothing out of the ordinary looking on the plugs. As far as "circuit test"...visual check the O2 sensor wiring and ring it with an ohm meter between the O2 plug and the ECM connector. Sometime, the connectors are corroded or burnt. Just make sure the battery's disconnected before you pull the ECM connector off.
Still not to clear as to why the long term fuel trim is always "0"...that's just not right. The short term negative number says...I'm shutting the fuel WAAAAY down to this beast. The closest it got to 0 was -7.8, but that's a snapshot only so I don't wanna diagnose based on a pic, it's like showing your buddies a headshot "only" of your girl...what's the rest of her look like?...ya know? Need a continuous feed. Upload your live test to youtube or something.
Still not to clear as to why the long term fuel trim is always "0"...that's just not right. The short term negative number says...I'm shutting the fuel WAAAAY down to this beast. The closest it got to 0 was -7.8, but that's a snapshot only so I don't wanna diagnose based on a pic, it's like showing your buddies a headshot "only" of your girl...what's the rest of her look like?...ya know? Need a continuous feed. Upload your live test to youtube or something.
#17
04-11-2018, 04:08 PM
Ok gonna grab some wires this afternoon an Ill run those tests an see what I come up with an upload it to YouTube.
The plugs are Ngk iridium.
I contact the place I had gotten the engine from, the engine has “stock” components. Although it is a reman it was bored .30 over.
I had purchased new cylinder head castings an a shop did a clean an grind on valves an transfered em out of my old heads
The plugs are Ngk iridium.
I contact the place I had gotten the engine from, the engine has “stock” components. Although it is a reman it was bored .30 over.
I had purchased new cylinder head castings an a shop did a clean an grind on valves an transfered em out of my old heads
#18
04-11-2018, 05:38 PM
So I’m not positive i am doing this correctly I have an ohm meter. I unplugged the harness at the ecm an have identified what I believe to be the upstream o2 sensor. Book says a4 is ground. An a24 is sensor signal.
I hook up my meter on the “headphone” section at 2000k an it reads 54.
I hook it up 200k an it reads 54.1
if not uploading a pic of my ohm meter Incase I’m on the wrong setting
Last edited by beau680; 04-11-2018 at 05:40 PM.
#19
04-11-2018, 09:23 PM
You wanna know at this point that the wiring is good. How'd the visual inspection go? If you've Id'd the slots in the ECM and the upstream O2 connectors, do they look clean and run either test lead to the connector at the ECM and the other (thru a jumper) to the O2 connector. you're looking for right around 0 ohms. Also, wiggle the wires around both connectors while continuing to measure resistance and see if the reading changes. If both read around 0 ohms, the O2 sensor cable is okay. This is either a 3 or 4 wire connector. 1 is the O2 sensor, 1 is ground for same, 1 is for the preheat circuit and, 1 is for preheat ground. If alls well, reconnect the O2 sensor and ECM cable back up, unplug the downstream O2 sensor and start her up and see what happens.