New Twist to "Car Wont Start" Any Ideas?

[Kevin Shasteen]

This problem arose on my car-and I have not solved it as of yet.

 

For starters...no pun intended: this problem doesnt care if the engine is cold or hot.

 

The problem is:

 

1) W/ignition key turned the starter is powered and engages the flywheel.

2) The engine turns but doesnt run

3) I know I am getting fuel as I can smell it when I open the hood

 

*NOTE: This alone made me think I am not getting any spark

 

But here is the [new twist], at least it is new to me.

 

After grinding the starter trying to start the engine for 30 seconds w/no luck...

 

I can have someone push start me & as soon as I pop the clutch the engine IMMEDIATELY fires. After the engine starts it runs perfect. The engine idles w/ease, the engine rev's w/out hesitation and I can drive any speed w/out any compromise to engine performance. I just cant turn off the ignition switch or else I will have to get someone to push start me again.

 

So, my question is:

What part of the engine systems on my car are not working but should be working, during cranking, while the car is sitting still -vs- what part of the engine systems are working when my car is being push started that allows the engine to start while being push started as opposed to a no start situation while the car is sitting still?

 

It is a mystery to me.

 

My car:

1) 1978 4spd Z w/a bone stock inline 6

 

Prior to this occuring:

1) Alternator failed & took out the Battery

 

while replacing the Alt & Battery I also performed a tune up:

1) Spark Plugs replaced

2) Spark Plug Wires replaced

3) Cap/Rotor replaced

 

After this "Eng. Wont Start" problem arose:

1) I replaced the coil w/a spare I had and it appeared to help for a day or two-then the engine went back to acting up.

 

I'm leaning toward the problem being an ignition module (Datsun Manual calls it an Ignition Transistor): but I cant find any parts stores, who have module testing machines, w/the correct adaptor plug to test my module.

 

I still dont see why the module would not function during cranking, while the car is sitting still, yet function perfectly fine during a push start.

 

It truly is a mystery to me-so if anyone else has experienced this problem before-please chime in: the suspence of not knowing is killing me

 

Kevin

(Yea,Still an Inliner)

[Cruez]

Sounds like its flooding the engine with gas. Check the cold start injector, it may be dumping more than it should when its starting.

 

Could be a bad connection on the cold start injector also...

 

I had that problem and I made it worse when I upped the compression and it didn't fire right off... It eventually quit working so I replaced it with the Haltech EFI. (needed it anyway)

 

Are they the same plugs you used before?... are they fouled again.?

[Pop N Wood]

OK here is what I would check on my 240 with a points type ignition.

 

The starter solenoid has an S terminal that powers the ignition circuit during cranking. On a points car it bypasses the ballast resistor to give full power to the ignition during start up (you probably already know this).

 

Thus if a connection is bad on this alternate power path, then the problem you described could exist. The ignition switch is in the circuit, so a bad key switch could be the source of your problem. Hook a voltmeter up and see if you have power to the ignition module with the key in the run and start positions.

 

Also there is a remote chance that something is shorting out in the cranking ignition circuit. I have had problems in the past with copper dust building up inside the starter solenoid and shorting this terminal to ground. (It was on a Cheby truck but hey, same layout.) If you pull the solenoid off you can easily disassemble the end with the contacts and clean it out.

 

I have no experience with 78 Z's so don't know if the ignition circuit is powered as above, but certainly something to check into.

 

BTW, just noticed your comment about the alternator and battery both failing. Can't rule out a short somewhere causing both problems.

[jeromio]

I'll bet it's the ignition switch. Mine failed in almost the exact same manor.

 

Here's the deal: There are 3 circuits in the switch: Acc. On, Ign. On and Start. But there are 4 leads, and I presume (without having actually opened up the switch), actually 4 distinct circuits. 2 of them are on Start. So when you turn the key to start, you have Starter On, but also "other stuff that needs to be on for the engine to run". So the accessories are Off during start, but the ECM, the Coil, etc. all need to be ON.

 

My switch was turning the Starter on just fine. But all that "other stuff" that is wired to the Ign. On circuit was being turned OFF!

 

Took me awhile to figure this out. But you can easily test this in a couple of ways. Just unplug the connector to the switch, and put test leads between the white/red wire (the main) and the other 4. From vague memory, I think black/yelloow is start. Don't remember the other 3. You can also just put a lead on the coil wire and verify that it is still hot while you start.

 

But the Ign. On circuit should Stay on when the key goes to Start. Not sure how a switch could fail in such a strange way, but I know mine did.

[Sumo]

jeromio is on the money it's sounds almost like the same problem my friend had with another car. Push start runs fine but wont fire when cranked at first. Solution was bad ignition switch, we found out that when cranking, power would actually shut off to the coil. Power to the coil was restored when put on the "ON" position. It may be related to something else like relays or bad contacts, but i hope this helps.

[Kevin Shasteen]

Thanks for the comments.

 

Cruez,

 

FWIW, the spark plugs are not the same type as before. I too thought maybe for some unknown reason I was flooding the engine-yet this would not explain why it starts perfectly during a push start: so I ruled out a flooding scenario.

 

While talking to a few others here locally someone also mentioned the ign.sw. but I too thought, prior to reading everyone's comments here, that this would be an oddball (unfeasable) failure.

 

Jerimio/Sumo

 

After reading Jerimio's explanation on the ign.sw. I now think that would probably be a better place to begin. The first time I tested the coil (off the engine) w/a multi meter-it tested within tolerances. As far as testing the coil on the engine, while cranking, will take a second pair of hands: looks like I'll have to hijack a friend from the BIG city to come out and help.

 

Jim,

 

Your comments about the starter: you are referring to the inside of the starter housing where the terminal is positioned, yes/no. You are suggesting if this were the case-the starter would engage and in turn rotate the crank: but as a result of the terminal being corroded, on the inside of the starter housing, there would be no fire going to the ignl.sw(?), hmmm-interesting. I honestly never even considered that option. BUT HEY-that is why I always post here: so much experience in one place surely someone will have gone thru the same problem before & point me in the right direction.

 

Thanks again for the comments. Anyone else reading this thread please feel free to add: until I get this thing solved.........IT AINT SOLVED , so any addt'l input is always appreciated.

 

Kevin,

(Yea,Still an Inliner: with starting problems)

[Kevin Shasteen]

For those of you who are Diagnosticians & for posterity's sake: here's some new info to my "Wont Start Problem".

 

Cruez got me thinking about a possible "Flooding Problem". So I asked myself what could cause a flooding problem when the Engine Management System really isnt getting extra fuel? Answer: Lack of Air could mimic a flooding system due to the air being minimized.

 

I thought I would double check the air intake system: specifically the air filter.....as I openend the air filter housing I found a "BLUE WAL*MART PLASTIC BAG" that had been sucked up into the inlet.

 

Well I didnt find a "Datsun/Nissan" Insignia on the Wal*Mart bag...this I think makes it safe to assume it doesnt belong there . So I removed it from the air filter housing & cleaned the air filter. Unfortunately it did not fix my "No Start Problem"...rather it altered the perameters.

 

Now my engine will start when it is cold: it just wont start during a restart attempt after the engine had been warmed up/car driven & then parked w/out being push started.

 

So, I'm still leaning toward one of the Fuel Injection Relays or the Ignition Module....I hate electrical problems!

 

Time will hopefully tell-as I have time to mess w/it.

 

Kevin,

(Yea,Still an Inliner)

[Kevin Shasteen]

Update (almost forgot about this one)

 

So, for posterity sake-in case anyone else has the same problems I had I will post the answer to this riddle. I finally had time to really do some diagnostics on the ole Z.

 

What I found was a few bad fuses. They were really tricky as they looked good even on close inspection they looked fine. At times the car would start perfect-then at other times nothing-w/a turn of the ignition switch there was nothing, not even a click: no gauges no nothing.

 

All three of the "Accessories" fuse box circuits were dead. Wait over night and in the morning when I would try it again the car would either start or I would hear a clicking sound. I found one of these fuses had broken in the middle of the bus fuse yet was not burned-so at times I was getting power to my gauges. Rpl the fuses and the gauges worked yet the clicking at the fuse box continued.

 

Long story short-my Ignition Relay was getting hot. So, in the summer heat my car would start on a cool morning yet once the relay heated up it was dead until it had a chance to cool down. When winter rolled around the relay would work fine as long as it didnt get hot. Once it began getting hot or almost too hot it would click upon my attempt to start my car.

 

So, rpl Ignition Relay and the defective fuses and all is well. Couldnt stop myself while in diagnostic mode my map light now works as well as my engine room light, door jam switches/cockpit light...and discovered my rear window Defooger Relay is also toast.

 

I am a happy camper now-my Z is no longer sick...happy Z-happy little Z: it now wags its tale when I approach.

 

Kevin,

(Yea,Still an Inliner)

[Dan Juday]

Kevin, you still haven't fixed the biggest problem with that car.

 

It's still short two cylinders!

[Guest Nic-Rebel450CA]

The types of fuses that were blown and that they were blown in a group might indicate a possible short to ground (possibly during startup). I'd take a look around for bad wires and such just to avoid future problems.

 

BTW, I agree with Dan. Additional cylinders are very good additions to any engine

[Kevin Shasteen]

Nic,

 

Thanks for the headsup...BTW, the fuse was not actually blown-my bad for giving an incorrect description. There was only one bad fuse and it was actually broken dead center, w/out any burn marks; so when circumstances were just right the two ends would actually touch and complete the circuit while other times they would not touch. On a 78z wiring schematic the three accessory circuits feed thru the ignition relay...so when my ignition relay heated up those three circuits would also go dead.

 

Kevin, you still haven't fixed the biggest problem with that car.., It's still short two cylinders!

 

.., as Kevin responds to Dan's comment with an exteme "In-bred, bonified, countrified, southern red-neck, hill billy accent, "I Herrd'at"!

 

Kevin,

(Yea, Yea, Yea, I know-I'm still an Inliner)

[Guest AmericanGodzila]

Kevin are you talking about the relay by the Driver side kick pedal? If so

where did you get your relay from?

[Guest 240Zdragon72]

I have a 240Z with the 280ZX conversion. The same thing happens to me. The car will start, but die in the run position. I then put a "jumper" wire from the + on the battery to the + on the coil. Turned the key, and she fired up and ran. Could my problem be just like Kevins? I also pulled the dash out to look at the back of the tach. No loose wires, or broken connectors. I think it might be both the switch and the relay. Any advice, she's my baby and needs to be driven

Thanks