Altima 2002 cranks but won't start

I'm working on my buddy's 2002 Altima. It cranks and acts like it's trying to start but doesn't start. He let triple-a look at it first and they found the valve cover gasket was leaking and one of the coils was a bit oily. That didn't make much sense to me as far as causing it not to start. They wanted to replace the gasket, the oily coil and the plugs. Trouble is one of the plugs got installed too tight and won't come out. Triple a said they have to get it out and wanted permission to try till either it came out or broke. that wsa the only way they would fix it. That would end up costing a fortune. So we got the car back from them. The other plugs looked ok so I didn't really think it was that. He had some old plugs. So we laid all four coils with plugs in them on metal and cranked the car. I got good fat spark on each plug. Next I pulled the fuel line at the engine and put a pressure guage on it. I only have an old-school one that does vacuum one way and pressure the other with the pressure just reading 10psi. (The only engine I work on these days is the chevy 350 in my boat.) But it had no needle stop so I gave it a shot anyway. The gauge completely whipped way past the 10psi mark and fuel started spraying out around where I had the hose connected to the gauge. So it seems like it's got plenty of fuel pressure. It's a single line fuel system with no return. The filter, pump, and regulator all in one unit in the tank. So fuel supply seems to not be the problem.

We did the obd2 thing, borrowed a scanner form autozone. We got two p0300 random multiple misfires and one p0113 intake air temp sensor circuit high. I wouldn't think the intake air temp sensor would keep it from starting at all. What I see on the net about the air temp sensor says that often there will be no symptoms other than the check engine light.

I see on the net the engine has had issues with the crank and cam posiiton sensors. There was a recall and they got replaced on this one quite a few years ago. Best prices I have seen on those is around $25 or $30 each. I hate to troubleshoot by replacing parts and my buddy is between jobs right now as well. Is there anyway to test those sonsors other than replacing them? Anyone know which sensor really controls the spark timing? And is there anything else I ought to be looking at that might be our problem? tia

Reply to
jamesgangnc
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Thanks. I tried spraying either in the intake tube and it didn't really change it much. It still acts like it wants to fire but won't start.

Since I posted the first time I also put a light bulb in one of the injector connectors. I saw the the bulb flicker when the engine was cranked so it seems like the injectors are getting signal. Saw this test idea while searching the web.

It ran fine before it started doing this so it must be a complete system failure somewhere.

If it had a timing belt I would say it had skipped some cogs because it has that :"wants to crank but doesn't" behavior you sometimes see when a timing belt gets out of wack and the cam and ignition still fire but at the wrong time. Trouble is this engine has a chain.

I'm still trying to get the crank position sensor out. The cam one passed static testing and the ground and power to it on the connector tested good as well. I'm thinking about swwapping thecrank and cam sensors just to see if I get a behavior change.

The dealer said they were replaced as part of the recall but the "allegedly new" crank one is not backwards the way I see a lot of peole describe it. That change was so you could take the bolt out before unplugging it. It's a total pia to get the connector off. Plus the cam one was completely plastic and it looks like the newer ones have a metal body.

Reply to
jamesgangnc
***** Chains can get loose, the tensioner may not be able to take up the slack, and they can jump some teeth. You need to know exactly whether your valve timing is right or not. Dont assume it is okay because it has a chain.
Reply to
hls

Chain problems are veyy unusual though. It only has about 80k miles on it and it was running normally before this.

I still can't find out definitively which position sensor the computer uses to control the injectors and spark.

Reply to
jamesgangnc

Chain problems are veyy unusual though. It only has about 80k miles on it and it was running normally before this.

I still can't find out definitively which position sensor the computer uses to control the injectors and spark.

******* I believe access to a really good shop manual for this setup would help you. If you dont want to buy one, maybe your local library has one.

Ditto not troubleshooting by replacing parts. This usually ends up with the owner spending a heck of a lot of money before he takes the car back to a mechanic.

Reply to
hls

"hls" wrote in news: snipped-for-privacy@giganews.com:

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did you check the bump switch in the trunk?? had that happen lots of times, doesn`t take much of a bump to set it off. KB

Reply to
Kevin Bottorff

With all the various sensors on newer cars, you need good diagnostic tools. and the ability to use and understand them.. Only time I had a car that suddenly wouldn't start it was a bad ECU. But it wasn't "trying" to fire. Just cranking. At that time I was working long hours and had a good mech for the car. He found the problem real fast and replaced the ECU. Cost me a couple hundred, but well worth it. I would have had no idea where to start. Even now, if it's an engine management electrical problem not revealed by OBD II, I would be lost in the forest. Some failures are documented for some cars, and throwing the part at it has a good chance of success. I looked around on the net for that just a bit and quit, because I saw

2.5's and 3.5's and you didn't say which it was. When I buy my next car and go beyond my current '97 I'm going to look hard at diagnostic scanning software. You might be better off in time and money towing that car to a good mech with diagnostic software. One thing about that problem, you know the problem is fixed just by driving it away.

--Vic

Reply to
Vic Smith

Leaking fuel pressure regulators sometimes cause no-start. Sometimes just cause rich running. And sometimes cause hydo-lock. Surprisingly, you probably won't even smell gas unless you pull a plug or vacuum hose. All 3 happened to my kid's or his girlfriend's cars. But the no-start was also the hydo-lock, on a V-8 Caddie. The rich running, hard-starting, bad idle were a Corsica 3.1 and a Dodge Dynasty. Just throwing that out there. I can see this causing no start on some engines, but I think you said you pulled plugs. BTW, if you get a bad fuel regulator hydo-lock, don't pull the plugs and crank - unless you live dangerously and have a fire extinguisher handy.

--Vic

Reply to
Vic Smith

why do you think that? fix the sensor, clear the code and try again.

many cars have "limp home", but air temp is an essential part of the air density calculation, and thus injection duration. it may be causing insufficient fuel to start the engine.

do you have access to a scope?

the crank position sensor, not cam. and technically, it's the computer that "controls" timing - the sensor just gives the input from which the computer can do its math.

Reply to
jim beam

By the way, I checked out this era Altima for a young family member. She wants one. All these cars have some issues regarding the engine which lead to starting problems or driveability. Google a little further and you will probably find them.

Reply to
hls

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