No crank or start

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Th8nos

TYF Newbie
Joined
Jun 13, 2022
Posts
12
Reaction score
11
I just bought a 98 2dr Tahoe, now here's my situation. It has a 3in body lift, I installed the motor and transmission along with the computer, harness and connectors. I also replaced all sensors, pnps, starter, new battery, etc. Now when I go to crank it, it doesn't do anything but it has power. I test for continuity and voltage from the crank fuse, starter relay and wiring and it checks out good. I also checked for ground at the battery, engine, body, and pcm and it shows. Forgot to mention I installed a new ignition switch as well, no luck. I can jump the relay and it cranks over as well from the starter itself but won't start. Sprayed starter fluid no spark. Connect scanner and it says unable to communicate turn key on BUT THE KEY IS ON, smh. I'm stumped. Can someone here help me out I'm ready to drive. Oh it's a non chipped key it that help.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
23,018
Reaction score
33,388
Location
Stockton, Ca.
I just bought a 98 2dr Tahoe, now here's my situation. It has a 3in body lift, I installed the motor and transmission along with the computer, harness and connectors. I also replaced all sensors, pnps, starter, new battery, etc. Now when I go to crank it, it doesn't do anything but it has power. I test for continuity and voltage from the crank fuse, starter relay and wiring and it checks out good. I also checked for ground at the battery, engine, body, and pcm and it shows. Forgot to mention I installed a new ignition switch as well, no luck. I can jump the relay and it cranks over as well from the starter itself but won't start. Sprayed starter fluid no spark. Connect scanner and it says unable to communicate turn key on BUT THE KEY IS ON, smh. I'm stumped. Can someone here help me out I'm ready to drive. Oh it's a non chipped key it that help.
sounds like a ignition problem, I am not sure of the troubleshooting tree on a obs perhaps @rockola1971
 
OP
OP
T

Th8nos

TYF Newbie
Joined
Jun 13, 2022
Posts
12
Reaction score
11
Check your fuses. One powers OBD pin among other things.
I've checked all the fuses and relays and they're fine. I'm getting voltage from the purple wire at the neutral safety switch when I turn the key to run. The switch is new and aligned properly. Would the 3in body spacers cause a no ground effect? When I checked for ground at the core support, fenders and the firewall student I gets nothing. My headlights don't come on but all other lights do. Put it in neutral and it turns over but not start. I know in missing something soooo simple and its giving me a headache. PCM is getting power and a ground just not the switch. I'm stumped
 

east302

Full Access Member
Joined
Dec 21, 2016
Posts
1,540
Reaction score
1,357
Location
Mississippi
I just bought a 98 2dr Tahoe, now here's my situation. It has a 3in body lift, I installed the motor and transmission along with the computer, harness and connectors. I also replaced all sensors, pnps, starter, new battery, etc. Now when I go to crank it, it doesn't do anything but it has power. I test for continuity and voltage from the crank fuse, starter relay and wiring and it checks out good. I also checked for ground at the battery, engine, body, and pcm and it shows. Forgot to mention I installed a new ignition switch as well, no luck. I can jump the relay and it cranks over as well from the starter itself but won't start. Sprayed starter fluid no spark. Connect scanner and it says unable to communicate turn key on BUT THE KEY IS ON, smh. I'm stumped. Can someone here help me out I'm ready to drive. Oh it's a non chipped key it that help.

You’ll have Passlock on a 98, but even if it’s tripped (Security light stays lit on cluster) it usually allows it to start for a moment before the VCM kills the injectors. Technically, though, it has to get a valid signal from the passlock module to enable the injectors. The passlock sensor at the ignition switch signals the module. There’s a reset procedure for that and is required following ignition switch replacement, but it sounds like you have a separate issue if the starter solenoid won’t even click using the ignition switch.

AD819AF7-A33F-4372-9560-E82ADCA46325.jpeg

I’ve usually had to clear the Passlock codes to get mine to reset, but it’s a catch-22 with your DLC issue. Maybe try the reset procedure anyway.

Here is the starter diagram for 1998:

C12FB446-5A01-43D1-BD5C-0843808115B8.jpeg

If you have voltage at relay B9 when turning the ignition switch, take a look at ground G105:

DB5E4ACF-81B5-43E3-AD2A-956C5728302E.jpeg

Edit: I reread your post - it cranks in neutral but not in park?
 
Last edited:

east302

Full Access Member
Joined
Dec 21, 2016
Posts
1,540
Reaction score
1,357
Location
Mississippi
PDFs of the 1998 GM shop manual can be downloaded here:


It has the diagnostic procedure for the DLC in volume 1 (pg 8A-50)
 
OP
OP
T

Th8nos

TYF Newbie
Joined
Jun 13, 2022
Posts
12
Reaction score
11
You’ll have Passlock on a 98, but even if it’s tripped (Security light stays lit on cluster) it usually allows it to start for a moment before the VCM kills the injectors. Technically, though, it has to get a valid signal from the passlock module to enable the injectors. The passlock sensor at the ignition switch signals the module. There’s a reset procedure for that and is required following ignition switch replacement, but it sounds like you have a separate issue if the starter solenoid won’t even click using the ignition switch.

View attachment 391035

I’ve usually had to clear the Passlock codes to get mine to reset, but it’s a catch-22 with your DLC issue. Maybe try the reset procedure anyway.

Here is the starter diagram for 1998:

View attachment 391033

If you have voltage at relay B9 when turning the ignition switch, take a look at ground G105:

View attachment 391034

Edit: I reread your post - it cranks in neutral but not in park?
Yes that is correct.
 
OP
OP
T

Th8nos

TYF Newbie
Joined
Jun 13, 2022
Posts
12
Reaction score
11
Does it have new ignition parts on the motor you just put in there? i.e distributor cap, rotor, wires, etc?

Was the motor running when removed from the donor vehicle?

Or is the engine setup new?

Tell us more about what you're working with.
The donor was driving perfect. It was my 98 4dr. During the swap I've replaced the distributor, ignition coil, plugs, wires, O2 sensors, crank sensor, starter, oil sensor, ignition switch and lock cylinder, all new. That's why I'm so lost to what could've happened. I even got a new battery and performed the 30 min relearn, zilch diddo.
 

east302

Full Access Member
Joined
Dec 21, 2016
Posts
1,540
Reaction score
1,357
Location
Mississippi
Are the PRNDL indicators on the cluster correct? Is the shift cable getting the lever at the transmission in park? Believe that park is rotating it all the way clockwise and that there’s a little clip that has to be pushed in at the cable in to lock it in place but it’s been a while.

If it cranks in neutral and is physically engaging in park then it seems like that would be a switch issue?

Wonder if the VCM has to see the transmission in park to communicate with the scanner? Never tried it in neutral.
 

Forum statistics

Threads
128,283
Posts
1,796,905
Members
91,032
Latest member
454cid
Top