Engine will not start

Tiny
BLURRZ
  • MEMBER
  • 1990 NISSAN 300ZX
  • 6 CYL
  • 2WD
  • MANUAL
  • 100,000 MILES
Hey guys,

I have a 1990 300zx with a JDM replacement motor.

I had a full buildup of corrosion in my radiator, so I decided to remove it and flush it with water so I can start flushing the coolant out in process of draining and refilling.

So after I reinstalled everything after a radiator clean/flush, It ran for a bit but then died and I couldnt get it to start again. The car will crank but wont start. Several sites advised me to check the ECU, and found that its giving code 11, Crank Angle Circuit.

I have the older PTU, which I read goes bad and I should get replaced by Nissan as it was on their list of recalls. Before I proceed on replacing my CAS, should I try to replace the PTU?

I also found that the ignition coil relay could also be a problem. I got the engine and some components wet under the hood which Im probably thinking I accidentally shorted out. Is there any way to short out the CAS by cleaning it on the outside, or getting water on the PTU?

Lastly I checked my fuel filter to see if It was getting fuel. I replaced it with a fresh one, and when I went to check if there was fuel in it there was. So I know its getting fuel.

Troubleshooting I checked the TPS, and sensors on the upper radiator inlet, there are two on the front of the motor. Took them off and cleaned them up. I also cleaned all connectors and pins on both the CAS, and TPS sensor to ensure that they were getting connection.

I also cleaned the MAF as well, took it off and reconnected it after cleaning the pins and connectors.

The Z cranks, and I can hear the fuel pump kicking in, but it just cranks and cranks, and does not fire.

Im also confused about the coil packs (ignition coils). When I order one I have to order 6 correct? Because these are what fire my spark plugs?

Also, if I get a new CAS and PTU can I use any of the years or a N/A version? They all look the same, or do I have to get a TT specific versions?

Thanks you for any help and for helping sort this out.
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Friday, May 28th, 2010 AT 4:59 AM

33 Replies

Tiny
KHLOW2008
  • EXPERT
Hi Blurrz,

Before we get to others, I would suggest diagnosing the Code 11 problem first which would be the crankshaft position sensor. Here is a guide to help you see what you are in for when doing the job.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Check out the diagrams (Below). Please let us know what happens.

Cheers
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Sunday, May 30th, 2010 AT 10:52 AM
Tiny
SAVERIO LUCIFERO
  • MEMBER
  • 1990 NISSAN 300ZX
  • V6
  • RWD
  • AUTOMATIC
  • 60,000 MILES
I tried spraying starting fluid into the air intake and it started but when I stopped spraying the car stopped. So this gave me the indication that its a fuel problem. I checked the fuel pump fuse and it is alright. My question is how am I supposed to know if it is the the fuel pump or gas line or even the fuel filter?
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
Check fuel pressure with a gauge auto parts rent it. Also, see if pump is getting power as most have a relay see picture, behind left kick panel. You also have a fuel pump control unit which could be bad as well which the ECM turns it on via the pink/black wire going to it. You should have forty three psi and may need an adapter because it has to be checked by fuel filter.
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
Hey we checked the fuel pump and it wasent working so we fixed it and know its running fine and the engine still wont start whats the next step if the fuel pressure is fine and the gas is running threw the gas lines take into consideration the car wasent started for 4 years thanks
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
Pressure for fuel pump should be 43 psi if not pump no good for both turbo an d non turbo. Check for spark as well scan for codes
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
Yes we got 43 psi and we checked the sparks are all fine could it be the fuel injectors
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
It cold be but you need to scan for codes see pics on how to do it then get back with code if any check all fuses if no ignition signal injectors will not fire so hold off on that.
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
I got code 55 what does that mean
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
No faults are detected. So try this link i'm sending pics and do these tests to see if it's an ignition problem. Do these in order also check resistance of coil from one post to another it should be.7 ohm
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HU777
  • MEMBER
  • 1990 NISSAN 300ZX
  • 150,000 MILES
My car wont start. I have a 1990 Nissan 300zx. When I go to start the car the starter motor works fine but cant turn over the motor at all. Any ideas?
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
WRENCHTECH
  • EXPERT
All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
When we took out the spark plugs they were dry is that a indication that their are bad ignition?
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
But their was sparks when we took them out
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
We tested 4 sparks out of 6 and they worked fine
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
Test what I showed in last reply you can still have spark but not enough to start a motor.
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
We tested all coil connectors they were all good and all had power
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
HMAC300
  • EXPERT
Have you tested the 3 items in pics I sent a couple replies ago? If you have then check compression then have a local guy look at it.
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
SAVERIO LUCIFERO
  • MEMBER
It started the problem was the spark plugs thanks
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
KEN
  • ADMIN
Glad you could get it fixed please use 2CarPros. Com anytime we are here to help

Best, Ken
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Tuesday, April 4th, 2017 AT 10:46 AM (Merged)
Tiny
MREFEBUS
  • MEMBER
  • 1990 NISSAN 300ZX
  • 168,000 MILES
I just bought 90 300zx and I have had it for at least 4 months now and wont turn on some times. I would use it for the day and then I won't turn on the next moment it turns over but won't start
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Tuesday, April 4th, 2017 AT 10:47 AM (Merged)

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