Mitsubishi 3000GT & Dodge Stealth Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
I recently bought a 97 SOHC 3k and i have been having trouble starting the car and i think it has to do with the PTU, CAS and the distributer. I have tested everything in that area and it looks good besides the ptu, which is not getting 12v. The car cranks fine and gets spark and fuel but wont start. Ive been working on it for months and cant figure it out. anyone have any suggestions?
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #2 ·
I recently bought a 97 SOHC 3k and i have been having trouble starting the car and i think it has to do with the PTU, CAS and the distributer. I have tested everything in that area and it looks good besides the ptu, which is not getting 12v. The car cranks fine and gets spark and fuel but wont start. Ive been working on it for months and cant figure it out. anyone have any suggestions?
Sorry i meant to say i have a 12v coming from the ignition coil but no spark when cranking
 

·
Registered
93 NA ATX 3000gt DOHC
Joined
·
4,175 Posts
The car cranks fine and gets spark and fuel but wont start. Ive been working on it for months and cant figure it out. anyone have any suggestions?
----------------------------------------------------
Sorry i meant to say i have a 12v coming from the ignition coil but no spark when cranking
Are you testing for spark from high-tension wire from coil to distributor cap or at spark plug wires?

Do you have 12v on White wire with black stripe at PTU connector pin 3, with ignition switch turned ON?
 

·
Registered
1997 3000gt SL 1999 3000gt SLTT
Joined
·
16 Posts
The barometric pressure sensor is built into the MAF. It will run with a baro code but your MAF wouldn't cause a no-spark. If you aren't getting spark its plug, coil, or sensor related. Crank angle sensor/crank position sensor will not allow spark if the ecu isn't seeing it. Line the sensor plate behind the timing cog on the crankshaft up with the crank position sensor, and backprobe the blue signal wire on the crank pos sensor connector with the key on. It should be pulsing 3v~ when the plate is sweeping between the crank pos sensor. If its not pulsing=bad sensor. I would check that next because it's a relatively simple fix and you can scratch that off the list
 

·
Registered
93 NA ATX 3000gt DOHC
Joined
·
4,175 Posts
The car cranks fine and gets spark and fuel but wont start.
Are you testing for spark from high-tension wire from coil to distributor cap or at spark plug wires?
You didn’t confirm if you checked spark at coil wire to distributor or at spark plug wires. But if you tested at spark plug wires that confirms every thing involved with the ignition side is working. Also you indicated getting fuel, not sure where and how you verified that but if both spark and fuel is present, you need to look at other possibilities.

If a engine has fuel, spark and compression at right place and time, it has to run.

Since you indicate having spark and fuel, you need to confirm compression and timing, both spark and mechanical timing (cams to crank). You should do following to narrow things down.

1) With timing light attached to #1 plug wire, while cranking engine and look for notch on harmonic balancer to be between 5° and 15° BTDC on timing indicator on timing belt cover.
click on image to enlarge

2) Run compression test on all cylinders.

3) If 1&2 above check out, check mechanical timing of both cams to crank position of #1 cylinder at TDC. Though you're not replacing timing belt, below image shows how crank and cam marks should be if mechanical timing is correct.
click on image to enlarge
 

·
Senior **i.e. OLD** Member
Joined
·
16,067 Posts
3) If 1&2 above check out, check mechanical timing of both cams to crank position of #1 cylinder at TDC. Though you're not replacing timing belt, below image shows how crank and cam marks should be if mechanical timing is correct.
@white93gt , Don....SOHC....

Bob. :)
 

·
Senior **i.e. OLD** Member
Joined
·
16,067 Posts
:unsure: Sorry Bob that one just went over my head. His is a SOHC that's why I posted that diagram. At my age I don't pickup on subtle hints anymore. :cry:
You're sorry?
I didn't even look at the diagram.
Come on Don, were both still doing this 3SI thing, so we can't be that old (?)....lol

I think it's awesome that you are still helping out.
I try when I can.

Don't know about you, but I edged, weed wacked, mowed and blowed today.
I'm still around....:)

Bob.
 
1 - 9 of 9 Posts
Top