Hello all, Have this quest in the shop with 15x,xxx miles on it that will not start. She states she parked one evening and it was running fine, went to start it the next morning and it would not hit a lick.. We had it towed in, confirmed customer concern. it cranks fine it has injector pulse, 40PSI fuel pressure, good spark and 100PSI compression. still no start, We thought it might have a restricted exhaust, but we opened the exhaust with not change at all. thought the timing belt might have jumped, removed timing covers and the belt is spot on. It appears as if somebody else installed a new distributor, I confirmed that it is timed correctly and the spark plug wire routing is correct. Any thoughts, questions, or concerns?? I'm afraid I am missing something simple but I obviously don't know that.
Thanks in advance!!
Any Dtc's? does scanner show cranking RPM ? ( I know that you said spark and inj pulse present, I have had many a crank no start that cranking RPM is jumping around and ECM is freaked out) Do you have scope & pressure transducer to see when the spark and fueling are happening ? 100psi sounds a bit low?
I agree with others check the fuel quality. Does it run on alternate fuel? Just last week I had used engine and clogged injectors, No injector pintle hump.
Good afternoon Leon, Sounds like you're doing due diligence here but I do have a couple thoughts: 1. Does it cough and sputter at all like it's trying to start or just a crank and nada? 2. What does the cranking sound like? Is it even or up and down like weak cylinders?100 p.s.i. seems kind of low to me but that may be a result of fuel wash from not starting. May be worth a relative…
Leon, I agree with the others about 100 psi being low. If you pull the plugs out to dry them & the cylinders, put a couple squirts of oil in each cylinder & recheck compression. That may help if the cylinders are washed down
Compression should be 128 minimum and 173 spec. Cylinders could be washed down with fuel, try and dry them out and change the oil, see if compression comes up into spec. Good luck.
Go back to the basics check critical data pids see if anything is skewed I also agree 100 psi is low,you might want to do a fuel quality test in case somebody was up to no good
Hey Leon. 100 psi of cranking compression does sound a bit too low. Nissan specifications for cranking compression is 160-180 psi...[ according to Identifix ]. Washed down cylinders will cause sealing issues. Try removing spark plugs and drying them out and giving it another shot. Does the vehicle even attempt to start??
I agree with the others with the compression readings being low.I had an older Altima that was a similar no start.When I checked the oil it was down 2 quarts.I topped off the oil and after about 10 cranks it started.You would be suprised how fresh oil effects older worn engines.Just a thought.
Are spark plugs fouled ??
Hi, is the firing order correct ? You say you have a good spark ! Have you tested at the plug leads or the coil ht lead . Use a spark tester at the spark plug ht leads see how far the spark jumps . Also as others have said is the fuel ok ? Will it attempt to start using easy start . Good luck some times the simple things can cause a lot of head scratching. Had something similar lately turned out…
yes the firing order is correct, it has a new distributor cap on it (yes, I know all the acronyms for NEW, LOL) fuel sample looks great
I bet it's just washed down, Vic.
Have you tryed holding gas peddle to floor or get some starter fluid BECAREFUL BE CAREFULLY to much is VERY BAD to see if it will run then that will lead to no fuel pass the injectors for the no start problem Like other posted is the system seeing the crank or cam output Fuel maybe reading 40 psi what is the amount of fuel passing in the in the line Did the owner happen to put wrong fuel…
Finally figured out how to upload pics so here are some screenshots of injector amperage and voltage, also compression.. notice on the injector amperage it has some oscillations when it lets the injector close and the same way on the voltage.. and the voltage does not have a pintle hump at all. I am kind of concerned about those oscillations, but what could possibly cause that?? all three…
What is your cranking vacuum
Hi Are plugs fuel soaked..? if so Carry out relative compression test with amp clamp & a scope.. Thanks..
Okay so I will have eat my half of the humble pie.... distributor timing was off by 180 degrees.. :(( in my defense there was no way of knowing that for sure without exposing the timing belt,, either way I turned it 180 degrees and she fired up and ran like a top..