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Ted G.
Ted G., ASE Certified Technician
Category: Nissan
Satisfied Customers: 6089
Experience:  20 years auto repair experience, ASE Master Tech, Expert Witness
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Maxima: i have a 99 maxima that has extended cranking on initial

Customer Question

i have a 99 maxima that has extended cranking on initial start but once it starts it will keep starting properly until the car sits for over an hour,have replaced fuel pump and ref crank sensor ti no avail,by the way the car is not throwing any codes
Submitted: 1 year ago.
Category: Nissan
Expert:  Ted G. replied 1 year ago.
Have you checked fuel pressure as it sits?
Customer: replied 1 year ago.
yes, initially it was only 20psi replaced the pump and the filter now have 41psi still the same problem
Customer: replied 1 year ago.
(Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Ted G. replied 1 year ago.
No, what is the fuel pressure after it sits for an hour?
Customer: replied 1 year ago.
I haven't let it sit for an hour but after 20 mins I still had 41psi
Expert:  Ted G. replied 1 year ago.
Do you have access to a scanner that can read parameters (live data)?
Customer: replied 1 year ago.
yes
Expert:  Ted G. replied 1 year ago.
Okay, I'd like to see what the ECT is reading when the engine is cold and if you can compare pulsewidth on the injectors on cold and warm start.
Customer: replied 1 year ago.
ect reading when cold is approximately the same as ambient air temp,unfortunetly my scan tool does not give me pulsewidth info
Expert:  Ted G. replied 1 year ago.
Okay, so at least the ECU knows it's cold. My thought is either the injectors aren't flowing enough or you may have a compression issue, how many miles on it?
Customer: replied 1 year ago.
the car has 206,000 but I,vechecked compression and have between 145 and 150 across the board also once you get the car to start initially it will start properly from then on until you let it sit for at least an hour,the one thing I've noticed is that during the initialstart process after the car starts to try to fire you have to put it the floor (basically clear flood mode) but my thought is if I had some leaking injectors the fuel pressure wouldn't hold the way it does
Expert:  Ted G. replied 1 year ago.
Okay two things. Check fuse 33 in the fuse box. This is the Start signal fuse and the Start signal is more important when cold (basically gives more injector pulse) also I ran across a bulletin that states to push the accelerator down 1/3 when having cold start issues, although the way it is worded I think they mean very cold. Check that fuse and we may have to check at the ECU for signal also.
Customer: replied 1 year ago.
ok I'll try that and get back to you
Expert:  Ted G. replied 1 year ago.
OK
Customer: replied 1 year ago.
fuse 33 is fine. shouldn't you get some kinda o2 response if you pull the line off the fuel pressure regulator
Expert:  Ted G. replied 1 year ago.
Yes, the fuel pressure should increase, which should richen the mixture, so you should see a change in the front O2 sensors.
Customer: replied 1 year ago.
Not seeing any change in idle speed or o2 readings
Customer: replied 1 year ago.
If regulator was stuck that would follow your idea from fuse 33 ie no increase in fuel flow
Expert:  Ted G. replied 1 year ago.
Yes, that is certainly possible. I have done a bunch of research on this today and I am also finding a lot of issues based on bad engine grounds. As a check for this if you have a set of jumper cables around, run a cable from the negative battery cable down to the bellhousing near the starter. As I understand it, the theory is that the starter is pulling ground from the injection system when cold and not allowing the injectors to open long enough. It is a simple test, but if it works, you can run a permanent ground and your problems are over. It seems to have fixed quite a few issues on that car.
Customer: replied 1 year ago.
Thanks will try it in the morning. Thanks for all the time you're taking on this I'm a mechanic and been working on cars for 30 yrs but this one is making me crazy! Hopefully we can figure it out . How does the money work for you? I'd like to make it worth the while but I hate that the app gets to share
Expert:  Ted G. replied 1 year ago.
LOL, I have to be paid through the service, but it works pretty good for me. We'll get this straight, I have been on several sites like iATN today and doing some other checking too. There are a lot of issues with the 98-99 for some reason and I have owned the older and newer generations and never had a lick of problem. It's this off the wall stuff where a strong scanner can save your bacon, but there is always another way.
Customer: replied 1 year ago.
Thanks ted I' m trying to get my hands on a good snap on scanner but I've used it before and I know it doesn't have the niss-2 connector so it only has obd2 functionality thanks again for the help and I'll talk to you tomorrow
Expert:  Ted G. replied 1 year ago.
You're welcome, talk later.
Customer: replied 1 year ago.
Ted tried jumper cables with no change. So I spent the morning rechecking all the tests I had performed. To my surprise when I recheck fuel pressure it goes to 40 as soon as you turn the key and then immediately drops to 20 psi. What should I have for pressure while testing?
Expert:  Ted G. replied 1 year ago.
No less than 34. Fuel pressure regulator?
Customer: replied 1 year ago.
I'm it now!
Customer: replied 1 year ago.
Sorry I'm checking it now
Expert:  Ted G. replied 1 year ago.
Let me know.
Customer: replied 1 year ago.
Ok
Expert:  Ted G. replied 1 year ago.
.
Customer: replied 1 year ago.
Fuel pressure regulator works fine . I pulled all the plugs again. They are all burning fine and I'm now ohm sing out the coils!
Expert:  Ted G. replied 1 year ago.
But how are you dropping to 20 psi if the regulator is working okay?
Customer: replied 1 year ago.
When you cycle the key the pressure goes instantly to 40 then drops to 20 but as soon as you start cranking the pressure goes up to 35 and stays there you can make it change by applying vacuum to the regulator so I don't see the problem here
Expert:  Ted G. replied 1 year ago.
Okay, got it. You know anyone that has a scope?
Expert:  Ted G. replied 1 year ago.
Just found what I was looking for. We need to see if you are getting a start signal to pin 20 on the ECU, here is a diagram.
https://www.dropbox.com/s/yl6dfdfzx838a3q/maxstart.JPG?dl=0
Customer: replied 1 year ago.
Thanks ted going to check it now
Expert:  Ted G. replied 1 year ago.
place holder, no need to respond.
Customer: replied 1 year ago.
Meant to get back to you sooner but found a few interesting conditions checked crank circuit as per diagram 12v while cranking started checking a few more things and while checking the cam sensor found the connector full of water then found out the customer " washed the motor and then these problems developed! Then disconnected crank sensor while motor was running and car still ran fine but no check engine code I'm beginning to wonder if she fried the ECU! Your thoughts
Customer: replied 1 year ago.
I meant cam sensor sorry
Expert:  Ted G. replied 1 year ago.
Well, you have to be careful with that because they often will disregard the cam sensor after the car starts, but that definitely could cause a hard start. Jeebus, you could have all kinds of sensors wet if she washed it. See if your scanner can see cam angle and that should tell you something, but that is pretty bizarre that it isn't setting a code. If nothing else you may need to just get all the connectors loose first and dried out. I will try to do some research on the cam sensor and see how the profile works, it may need a couple of drive cycles to set a code. But if it doesn't your ECU theory is looking pretty good.

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