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97 D90-SW, Arles +4.6
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Discussion Starter · #1 · (Edited)
Just did a bunch of work to pull my valve covers and replace gaskets. Which involved disconnecting a lot of engine harness connectors.

Re-assembled everything carefully and rover won’t start.

Turning ignition does nothing - no attempt to fire. Battery is showing 12.47 and I hear the fuel pump kick in on ignition pos 1.

Check engine light is on but only shows code p1138 which apparently is o2 sensor.

I’m guessing i didn’t connect some sensor right that gems requires before starting. Checked MAF connection and intertia switch and they are plugged in correctly (doesn’t mean they are working of course ;)).

I’m guessing it’s something obvious. Any ideas what to try next?
 

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When you turn the key to the start position does the starter engage and rotate the engine?
 

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Check battery and starter connections , especially the little starter one that connects to the solenoid
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #5 ·
is that #71 in this diagram on the plenum side?

thanks for the quick replies btw!
463436
 

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Wouldn't be able to tell you. I would physically check the connections on the starter itself and physically check them on the battery
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #7 ·
followed the starter and multi-plug is still plugged in fine, wasn't one i had touched. 12v across the 60a ignition fuse. feel like something else is wonky - does the GEMS 97 have an immobilizer or something? didn't think it did - and can't find anything searching.
 

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followed the starter and multi-plug is still plugged in fine, wasn't one i had touched. 12v across the 60a ignition fuse. feel like something else is wonky - does the GEMS 97 have an immobilizer or something? didn't think it did - and can't find anything searching.
There is an "immobilizer" button on the 97's. It is located on the bulkhead, just above the MAF side of the air filter -- it is a black rubber cylinder with a push button on the top. Unsure if that is your issue and you may have already , but if the only fault code you are getting is for an O2sensor, I don't think that should keep your 90 from starting.

Although you mention inertia switch, which may be the same thing...
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #9 ·
There is an "immobilizer" button on the 97's. It is located on the bulkhead, just above the MAF side of the air filter -- it is a black rubber cylinder with a push button on the top. Unsure if that is your issue and you may have already , but if the only fault code you are getting is for an O2sensor, I don't think that should keep your 90 from starting.

Although you mention inertia switch, which may be the same thing...
Thanks. Yeah my understanding or that thing is that it’s a inertia switch that cuts off the fuel in the event of a roll/collision. I tried both resetting and shorting it out, no effect. My guess also is that if it was this then engine would stillattempt to crank but not fire.

I’ll get under it again today and confirm voltages on the starter and starter solenoid.

In looking around some more I did learn that the 97 has an I immobilizer unit inside the dash binnacle that needs to confirm something with the ECU, but there isn’t much detail about it or if it could cause my issue. I’ll start digging into that more if there is no solenoid voltage at ignition time.
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #10 ·
Confirmed that the starter motor has power, but the solenoid is not getting voltage when turning the ignition key. Guessing next steps are to test the starter-relay and then figure out if the ECU immobilizer thing isn't happy.
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #11 ·
Found this in the 1997 NAS electrical manual. Interesting that it suggests that there is a bypass of holding key for 5 seconds. In my case doing that does nothing and also the Check Engine light does come on, so based on this I'm guessing it's not the immobilizer that is causing it.

Back to finding and testing the starter relay...

463489
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #12 ·
Updates:
  • Found and pulled starter relay and bench tested it - it works fine.
  • Tested red/white terminal coming off ignition switch and confirmed that it is sending out 12v when in starting position.
  • if i put my finger on the starter relay and turn key to starting position, i don't feel anything, so power is clearly not getting to the relay.

Found this awesome diagram for the 1997 which shows there is an "Automatic Inhibitor Switch" (is this the inertia switch?) and the Immobilization ECU are the only two things in the way, and some header joints whatever that means,

Why do I feel like a flat bed tow to a dealership is in my future...

463490
 

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96 D1 5 speed
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I've got $5 on the crankshaft position sensors harness having gotten nicked on reassembly
 

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96 D1 5 speed
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wouldn't a failed CKP throw the check engine light per the manual:

View attachment 463491
no not necessarily. I've seen 4 gems 4.0's not throw codes for it in the past year. Sounds crazy, but seems like every no start/running bad issue all circled back to that
 

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97 D90-SW, Arles +4.6
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Discussion Starter · #16 · (Edited)
WINNER. there was a round 4-pin plug disconnected in the area just below the MAF. is this the CKP plug? either way - it must have popped out when i lifted the loom to access the covers.

fired right up. thanks all. love this forum, knew it had to be something simple...

where do i send the $5?

463494
 

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97 D90-SW, Arles +4.6
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311 Posts
Discussion Starter · #17 ·
According to the manual the plug that was disconnected was the "transmission neutral sense wire" - which now makes complete sense why it was doing nothing if it assumed it wasn't in neutral. mystery solved.
 
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