Need Your Help Guys...

[gsrboy]

Guys I am in need of some advice/help with the car. The car is not cranking and will not prime fuel at all. I tried everything and it still has the exact same problem.

I was replacing my factory injector plugs with a solder on kit for the injector dynamic. I was also working on my "wire tuck" as well. When I go to start up the car it did not crank or prime. I took off the ITB's and realized I smashed one of the injector lines between the ITB and the head. I took it off and fixed the line, but had the exact same problem. I checked all the fuse and it is all working. I tried a factory ECU to see if it would prime/crank. I tried a working main relay, fuel pump relay and the same problem. I cleaned all the grounds and made sure its working and still have the same problem. Yesterday I even replaced the engine harness with a factory one and still have the exact same problem.

I am really stuck right now and do not know what is wrong with the car. I literally tried everything and checked all fuses and I have no clue why the car would not prime or crank.

I need your help guys, is there something I haven't thought about?

Thanks
-Tuan

 

[Hapa88]

Explain "will not crank". As in it will not turn over? Like the starter tries to turn the engine over and can not do it? Or the starter turns the motor over but the car doesn't fire up?

If it's turning over but no fuel is priming, that's usually the main relay.
If it's not even turning over, is your battery ok? Does it have enough charge?

 

[gsrboy]

Hapa88,

thanks for the reply. The car does not crank at all. The starter doesn't turn. There is plenty of battery and I even hooked up a jumper to it just in case and still nothing. I don't know what would cause both the crank/fuel at the same time. I did replace the main relay with a working one just to see if it was the problem but it had the same problem.

 

[Old Guy]

The starter motor circuit is independent of the fuel / engine management system. If the starter motor is not engaging and the battery and battery connections are good, the common suspects are:
1. Faulty ignition switch
2. Little plug has fallen out that engages the starter interlock switch on the clutch pedal
3. Starter solenoid has failed
4. The wire to the starter solenoid has become disconnected

I presume that when you turn the ignition switch to the start position, you can't hear the starter solenoid clicking. I am also going to presume that everything was working fine prior to you doing your work on the car. Since you were doing a wire tuck, I am going to hazard a guess that you have pulled the wire off the solenoid, pulled a connector apart in the solenoid circuit or cut the wire to the solenoid somehow.

You can do a quicky test of this by briefly applying +12v to the solenoid contact on the starter motor using a remote starter switch. If the starter engages the solenoid and starter motor are OK and you likely have a wiring issue. If the starter does not engage, you have a starter / solenoid problem. Obvious point - when you do this test, make sure key is not in the ignition and the car is in neutral.

 

[Zishan]

Might be worth a shot.....but possibly the kill switch? Try closing the doors and arming the car and disarming it and re-try...if you have an alarm.

Good luck, - Z

 

[Chu_Viet]

I am having the same problem.. Im gonna replace the ignition switch to see if that works.

 

[davidf]

The ignition switch is a fairly simple task to disassemble/clean/reassemble, instead of replacing it.

I am having the same problem.. Im gonna replace the ignition switch to see if that works.

 

[96cxt]

Questions....

When you turn the key to the ON position, does the dash light up? (as in does the engine light, TCS, etc lights come on?)
If nothing comes ON, check the battery terminal and double check that the terminals are in their proper place +/-, the terminals are clean and getting good contact, the terminals are tight. Make sure the NEG terminal is grounded properly.
2nd, if above is correct I would test the ignition switch and make sure the harness plug is properly connected to the key cylinder on the steering column.
3rd, if above is correct check to see if you are getting power to the main relay from the ignition switch.

 

[nsx20014me]

I had a similar problem with fuel delivery. The car just died while driving down the road. I don't remember if my engine cranked over or not. Apparently the fuel pump is on the same circuit as your O2 sensors. My O2 sensors extension wires go too close to my exhaust and melted off the insulation causing a short. New extensions were put in and carefully checked they were not too close to the exhaust pipes. Work was done by Driving Ambition.

 

[gsrboy]

Hey guys thanks for the reply,

So the dash light does go on. Not the tcs or chen engine though. I am on aem ems though. For the o2 sensor i am running an aem wideband. I checked the battery connection and it's good.

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Might be worth a shot.....but possibly the kill switch? Try closing the doors and arming the car and disarming it and re-try...if you have an alarm.

Good luck, - Z

Z,

I do not have an alarm system or a kill switch... atleast I don't think so.

I am having the same problem.. Im gonna replace the ignition switch to see if that works.

So no fuel/crank either? Does all your dash light up? When you turn the key do you only hear a click?

Questions....

When you turn the key to the ON position, does the dash light up? (as in does the engine light, TCS, etc lights come on?)
If nothing comes ON, check the battery terminal and double check that the terminals are in their proper place +/-, the terminals are clean and getting good contact, the terminals are tight. Make sure the NEG terminal is grounded properly.
2nd, if above is correct I would test the ignition switch and make sure the harness plug is properly connected to the key cylinder on the steering column.
3rd, if above is correct check to see if you are getting power to the main relay from the ignition switch.

I will check. Thanks!

 

[96cxt]

So plug in your stock ecu and check to see if the check engine light comes on and then shuts off.

I am also on AEM EMS and I'll check once I get home to see if my check engine light comes on when I turn the key to the ON position. (I'm pretty sure it does but I'll double check)

It seem like you have missed a ground wire some where. Can you trace back to see if you are getting ground to the wire on the ECU?

Do you have a jumper harness on the ecu?

 

[gsrboy]

Sorry to mention, with the stock ecu it does the exact same thing with the dash lights. It would be great if you can check on your car though. I double checked all the grounds and they all seem good.

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And I don't had a jumper harness for the car.

 

[shawn110975]

but cleaning the ign and it happens again when you dont have the tools to do it lets say in a parking lot miles from your house.
just buy a new one. and forget about it..... if thats the problem.

 

[Chu_Viet]

i have no dash light, but my key ring lights up orange. when i turn the key a few dash light comes on but doesn't crank or anything. i do hear a lil clicking noise. i'm guessing its my fuel. just waiting for the ignition switch to come in. i don't want to clean it because it's an 91 model. i don't want to deal with it again if it's the issue.

Hey guys thanks for the reply,

So the dash light does go on. Not the tcs or chen engine though. I am on aem ems though. For the o2 sensor i am running an aem wideband. I checked the battery connection and it's good.

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Z,

I do not have an alarm system or a kill switch... atleast I don't think so.



So no fuel/crank either? Does all your dash light up? When you turn the key do you only hear a click?



I will check. Thanks!

 

[96cxt]

i have no dash light, but my key ring lights up orange. when i turn the key a few dash light comes on but doesn't crank or anything. i do hear a lil clicking noise. i'm guessing its my fuel. just waiting for the ignition switch to come in. i don't want to clean it because it's an 91 model. i don't want to deal with it again if it's the issue.

If your fuel pump is coming on i'm guessing your switch isn't the problem. It's your clutch switch. Check the plastic plug that engages the clutch switch as Old Guy mentioned in post#4 above.

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Sorry to mention, with the stock ecu it does the exact same thing with the dash lights. It would be great if you can check on your car though. I double checked all the grounds and they all seem good.

- - - Updated - - -

And I don't had a jumper harness for the car.

In my car with the AEM EMS the check engine light comes on and at the same time I hear the fuel pump kick on. So i'm guessing you aren't getting power to the main relay. Can you run a test light to the main relay and see if you are getting both +power and -ground to the main relay. If not then supply the power or ground it isn't gettting to see if that will help turn the engine.

Have you rewired or added any new electronic on the inside of the car? If so, is it possible that any wires can lose or pinched or cut?

Hope this helps.

 

[Old Guy]

If your starter motor is still not engaging, don't go fiddling around with your EMS. The EMS has nothing to do with the operation of the starter motor (exception - see my comments on Na2 cars at the end of the post)! The more unplugging and plugging stuff back in you do (especially on older cars) just creates new potential failure spots from weakened connections.

I have attached a .pdf document showing the wiring diagram for the starter motor (encircled in red) for the early model years (I am guessing that you have an Na1 model). As you can see, it is pretty simple. The only item that I did not mention as a possible failure item in my initial response is the starter cut relay (I am not aware that this has been a common failure item). As you can see from the wiring diagram, if the starter cut relay does not get energized, neither the starter motor solenoid or the fuel injection main relay get power during start up. The starter cut relay gets +12v from the ignition switch and is grounded through the clutch pedal interlock switch and then the security control unit (black/yel wire on the security unit).

I have also attached a .pdf of part of the test procedure for the security control unit . As you can see from the test procedure, if you ground the blk/yel wire on the 22 pin connector at the control unit (make sure connector is removed from control unit!), the starter motor should crank. Be aware that the engine may start since the key has to be in the start position and the clutch pedal pressed in during this test. If it doesn't crank, then the problem is one of the following: a faulty ignition switch, starter cut relay, clutch interlock switch, starter motor / solenoid or wiring to same (most of the stuff that identified in my initial comments). If the starter motor does crank over then the problem is with the security control unit (have a fun time diagnosing that one - lots of wires and switches!).

If you can get the starter motor to operate and the engine still does not start, then you have moved your problem from the starting circuit (a relatively simple thing to diagnose) into the engine management system and its associated stuff (a potential world of hurt!).

The diagrams I attached are from the '91-'92 service manual on Dali's site. You might want to check the manual for your specific year to see if there were any color changes to the wiring. If you have an Na2, then you should definitely be checking the service manual; although, I don't think there were any material changes to the starting circuit (The immobilizer circuit in the EMS does get tied into the starting system - the fact that you have an aftermarket EMS makes me guess that you don't have an immobilizer)

 

[Chu_Viet]

Okay, ill check the plastic tomorrow, but my car is an auto to manual swap. The previous owner did itto where i dont have to engage the clutch to start the car.

If your fuel pump is coming on i'm guessing your switch isn't the problem. It's your clutch switch. Check the plastic plug that engages the clutch switch as Old Guy mentioned in post#4 above.

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In my car with the AEM EMS the check engine light comes on and at the same time I hear the fuel pump kick on. So i'm guessing you aren't getting power to the main relay. Can you run a test light to the main relay and see if you are getting both +power and -ground to the main relay. If not then supply the power or ground it isn't gettting to see if that will help turn the engine.

Have you rewired or added any new electronic on the inside of the car? If so, is it possible that any wires can lose or pinched or cut?

Hope this helps.

 

[Chu_Viet]

Also when i put the key in, its just making the beeping noise, no dash light. Just the orange keu hole is lid up.

 

[Old Guy]

Also when i put the key in, its just making the beeping noise, no dash light. Just the orange keu hole is lid up.

Is the beeping noise the normal key in the ignition - driver's door open alarm or something different?

The automatic transmission cars have some kind of equivalent switch to the clutch switch (shift position console switch). Since I don't have an automatic I am not sure where this is located. I am guessing somewhere in the center console area. However, since your car is a conversion, it is an open question as to what the individual who did the conversion did with this switch. If they bypassed the switch and the wires have become disconnected, then the starter cut relay is not going to pick up and the starter motor is not going to engage. Since you have a 'blended' car, you are kind of on your own with trying to figure out if this is part of your problem.

In you initial post, you said you got some dash lights when you put the key in and turned it. Did you get dash lights when you turned the key to the run position but no lights when you turned the key to the start position?

Last question - have you checked the condition of your battery and the battery cable connections? If you have a weak battery or the battery cable clamps are loose or corroded, you may lack adequate voltage to engage the starter. The clicking you hear may be the starter solenoid engaging but there is insufficient voltage at the starter to turn it. A simple test is turn the interior lights on in the car and then attempt to start the car. If the lights go really dim or out, you have a bad battery or bad connections to the battery.

 

[Chu_Viet]

today i tried to look for the clutch switch. i really don't know what i'm looking for. it's really tight in that area even with the knee bolster off. when i put the key in and the door is open, it makes that beeping noise. i checked my connection and it's really tight. i have a brand new optima yellow battery i tried it with, still no crank. the only power i see is the orange key hole now. when i try to crank, it goes silent with no beeping noise. headlights won't pop up or anything. my new ignition switch is coming in next week, hopefully this is the problem.

thanks for everyone's help btw.

Is the beeping noise the normal key in the ignition - driver's door open alarm or something different?

The automatic transmission cars have some kind of equivalent switch to the clutch switch (shift position console switch). Since I don't have an automatic I am not sure where this is located. I am guessing somewhere in the center console area. However, since your car is a conversion, it is an open question as to what the individual who did the conversion did with this switch. If they bypassed the switch and the wires have become disconnected, then the starter cut relay is not going to pick up and the starter motor is not going to engage. Since you have a 'blended' car, you are kind of on your own with trying to figure out if this is part of your problem.

In you initial post, you said you got some dash lights when you put the key in and turned it. Did you get dash lights when you turned the key to the run position but no lights when you turned the key to the start position?

Last question - have you checked the condition of your battery and the battery cable connections? If you have a weak battery or the battery cable clamps are loose or corroded, you may lack adequate voltage to engage the starter. The clicking you hear may be the starter solenoid engaging but there is insufficient voltage at the starter to turn it. A simple test is turn the interior lights on in the car and then attempt to start the car. If the lights go really dim or out, you have a bad battery or bad connections to the battery.

 

[Old Guy]

You say that your headlights will not operate any more which makes me think that your battery is close to being dead or you have a problem with the connection of the battery cables. The headlights are supplied directly off of the battery bus (they are not switched through the ignition switch) and as such are unaffected by whether the ignition switch operates or does not operate. If the headlights won't operate, its not a problem with the ignition switch!

Some NSX owners have noted problems with corrosion and loosness of the negative battery cable where it connects to the body which results in failure to start due to low voltage. Something you can check.

Have you let the car sit without being used for a couple of weeks? I have no experience or particular knowledge about Optima batteries but others on Prime have noted that the parasitic loads in the NSX can drain some of the Optima batteries dead in a week or two if you are not using the car.

There is a voltmeter in the instrument panel of the NSX which you can use to carry out some test on the battery. With the ignition switch in the run position, the voltmeter should read 12 - 14 volts (this presumes that the ignition switch is good!). If it reads less than this, your battery is discharged. If it reads 12-14 volts, try operating the headlights. If the voltage drops a lot, the battery is toast, or you have bad connections on the battery or where the negative cable connects to the body. As noted, this test requires that your ignition switch is good. If you have access to a voltmeter (one of those cheap $15 ones from an auto supply store works fine), you can carry out these same tests (don't need to rely on the voltmeter on the instrument panel) by getting someone to measure the voltage directly across the battery terminals while you do the tests.

 

[Old Guy]

Chu_Viet

Here is the .pdf showing the battery connections on the car body.

 

[Tech7042]

Sorry to mention, with the stock ecu it does the exact same thing with the dash lights. It would be great if you can check on your car though. I double checked all the grounds and they all seem good.

- - - Updated - - -

And I don't had a jumper harness for the car.

If the check engine light does not illuminate when the key is turned ON (should light up for about 2 seconds and then turn off) that means the ECU is not powering up. No power to ECU obviously means no start. It's not the starter or the battery. Next step is finding out WHY.

If you have an ETM, and can read it, simply find out what wire/s supplies power to the ECU, and test for voltage at that connector pin. If you have voltage, then check ground.

 

[Old Guy]

If the check engine light does not illuminate when the key is turned ON (should light up for about 2 seconds and then turn off) that means the ECU is not powering up. No power to ECU obviously means no start. It's not the starter or the battery. Next step is finding out WHY.

If you have an ETM, and can read it, simply find out what wire/s supplies power to the ECU, and test for voltage at that connector pin. If you have voltage, then check ground.

Tech7042 - you are 100% correct that if the MIL light is not lighting up, that save for a burnt out MIL bulb, there is a problem associated with the ECU and the engine is not going to run. However, from looking at the wiring diagram for pre immobilizer / Na2 cars, there is no interlock from the ECU back to the starter circuit. As such, the starter motor should be able to crank the engine even if the ECU is inoperative, the engine just won't start.

The reason I kind of go on ad nauseum about the fact that the starter motor is not operating is that there are a bunch of common mode failures that disable both the starter motor system and the ECU. i.e., there is stuff in the starter motor system that will disable both the starter motor system and the ECU; however, there is nothing in the ECU / fuel system that will disable the starter motor circuit. The common mode failure items are:

1. Battery
2. Battery connections
3. #29 50 A fuse which supplies the ignition switch
4. Ignition switch
5. Starter cut relay (the ECU gets voltage from the starter cut relay via fuse #7 to power up the fuel pump through the FI main relay plus I expect power the ECU during the start sequence)
6. Clutch interlock switch (controls the starter cut relay)
7. The security system and Security Control Unit (because the SCU controls the starter cut relay and stops everything from operating)

For good measure, the security control unit and the ECU appear to have at least one common shared fuse which would likely kill everything also!

If the starter motor system does not operate, the above gives you a list of relatively easy (and inexpensive) things to start checking and systematically eliminate as sources of the problem that can kill both systems. Conversley, if the starter motor does operate and your MIL does not light up, then you can likely eliminate the above list as being a possible source of the problem for the ECU and move on to other likely (and potentially more expensive) suspects such as the FI main relay, a broken wire or bad connection in the supply to the ECU, the fuses that are specific to the ECU or forbid, a toasted ECU.

Just an observation, the NSX does not lack for fuses! There are lots of the control units that have power supplies where there are two fuses in series and I think I traced out one that had three fuses in series (all of which would kill the system). You need the wiring diagram in the service manual to spot all the potential fuses that could blow and cause problems for whatever system you are trying to fix!

The above comments about the separation of the starter motor system and the ECU are based upon my read of the wiring diagram for the early cars (pre immobilizer, pre Na2). If I have screwed up and missed a sneak interlock from the ECU that blocks the starter motor system, I apologize profusely in advance for screwing people up; however, I think my observations are correct.

 

[gsrboy]

Thanks Old Guy! I will try that out this weekend! I will give you updates.