PSI Conversion

[Vince@Meanstreets]

Originally Posted by Swain

No start it wants to start it sounds like but nothing

po135 is the heater circuit....ASD relay controlled.

Have you called PSI again yet?

[Vince@Meanstreets]

Originally Posted by 67Rally

Make sure you have 12v going to red ignition wire with "key on & cranking".

The wire I fed it with had power with key key on only, but nothing when cranking. It would turn over, but not fire up. It's a fairly common issue (sorry if you have already checked this).

Originally Posted by Swain

So my new Vaporworks tanks in. I hooked up a scanner to the car and its throwing a P0135 code. The scanner says Crank sensor but I changed it. Online forums says o2 sensor. Hmmmm

J,

Did you check for this?

We add a relay to provide 12v to the ignition circuit during cranking. Also double check your power and ground circuits. Something ain't right.

[Swain]

Originally Posted by Vince@MSperfab

J,

Did you check for this?

We add a relay to provide 12v to the ignition circuit during cranking. Also double check your power and ground circuits. Something ain't right.

I am going to check to check the injectors with a NOID light. It will fire for a split second. I think the ignition switch could be bad? Maybe its dropping too much while cranking?

[Vince@Meanstreets]

Originally Posted by Swain

I am going to check to check the injectors with a NOID light. It will fire for a split second. I think the ignition switch could be bad? Maybe its dropping too much while cranking?

If it is the factory style switch in the dash it will provide zero voltage while cranking. This system ran 12v cranking voltage from the resistor bypass on the starter.

You can run a relay with a diode to use the purple starter wire as a signal to send 12v to the ignition circuit.


Vince

[Swain]

Originally Posted by Vince@MSperfab

If it is the factory style switch in the dash it will provide zero voltage while cranking. This system ran 12v cranking voltage from the resistor bypass on the starter.

You can run a relay with a diode to use the purple starter wire as a signal to send 12v to the ignition circuit.


Vince

Thanks Vince,

I have been thinking about this a lot. I am going to try this tonight or tomorrow.

[Vega$69]

Originally Posted by Vince@MSperfab

If it is the factory style switch in the dash it will provide zero voltage while cranking. This system ran 12v cranking voltage from the resistor bypass on the starter.

You can run a relay with a diode to use the purple starter wire as a signal to send 12v to the ignition circuit.


Vince

You don't need any additional relays or diodes.

I've done 5 LS swaps on 1st Gens all with factory ign switches. 3 GM Perf Harness, 1 Psi and 1 reworked GM take out harness.

LS ECM

You need 12v switched power to the PSI fuse box.

The ECM is powered up with ign 12v. When you turn the key on the ignition and fuel pump relays close.

When you hit start the purple wire provides 12v to the starter.

From PSI

NO-START
1. Red Ignition Wire (From back of Fuse/Relay Center) has 12-volts with the Key in the ON
position and CRANKING position. This cannot be stressed enough, most NO-START
conditions can be traced to this wiring issue.
2. Check that 2 Large Ring Terminals by Crank Sensor are connected to CONSTANT POWER.

Batt. Battery Positive (2 LARGE RING TERMINALS COVERED IN BLACK HEAT
SHRINK), These are often mistaken for ground wires because of the black heat shrink

[Swain]

Thanks for all the help. Soooo I think I know what's wrong the car will start for a second if it's been sitting for an hour or so. I think the injectors are clogged or not working. They were new injectors they were from a friend that works at Magnuson Superchargers. I think the were sitting for some time as the car smells like stale fuel. Either the injectors aren't getting power or the injectors are clogged. Testing that tomorrow. If all else fails I got a guy coming to look at it this Sunday.

Originally Posted by Vega$69

You don't need any additional relays or diodes.

I've done 5 LS swaps on 1st Gens all with factory ign switches. 3 GM Perf Harness, 1 Psi and 1 reworked GM take out harness.

LS ECM

You need 12v switched power to the PSI fuse box.

The ECM is powered up with ign 12v. When you turn the key on the ignition and fuel pump relays close.

When you hit start the purple wire provides 12v to the starter.

From PSI

NO-START
1. Red Ignition Wire (From back of Fuse/Relay Center) has 12-volts with the Key in the ON
position and CRANKING position. This cannot be stressed enough, most NO-START
conditions can be traced to this wiring issue.
2. Check that 2 Large Ring Terminals by Crank Sensor are connected to CONSTANT POWER.

Batt. Battery Positive (2 LARGE RING TERMINALS COVERED IN BLACK HEAT
SHRINK), These are often mistaken for ground wires because of the black heat shrink

[Vince@Meanstreets]

Originally Posted by Vega$69

You don't need any additional relays or diodes.

I've done 5 LS swaps on 1st Gens all with factory ign switches. 3 GM Perf Harness, 1 Psi and 1 reworked GM take out harness.

LS ECM

You need 12v switched power to the PSI fuse box.

The ECM is powered up with ign 12v. When you turn the key on the ignition and fuel pump relays close.

When you hit start the purple wire provides 12v to the starter.

From PSI

NO-START
1. Red Ignition Wire (From back of Fuse/Relay Center) has 12-volts with the Key in the ON
position and CRANKING position. This cannot be stressed enough, most NO-START
conditions can be traced to this wiring issue.
2. Check that 2 Large Ring Terminals by Crank Sensor are connected to CONSTANT POWER.

Batt. Battery Positive (2 LARGE RING TERMINALS COVERED IN BLACK HEAT
SHRINK), These are often mistaken for ground wires because of the black heat shrink

are talking about the PSI harness or the factory GM fuse panel?

I was thinking he might have those mixed up but the PCM is powering up from his description.

[Che70velle]

Jay, pull a spark plug. If it's wet, the injectors are firing. The noid light will help you in seeing if they are firing. You'll be amazed at how simple your problem was, once the car starts.

[Vega$69]

Originally Posted by Vince@MSperfab

are talking about the PSI harness or the factory GM fuse panel?

I was thinking he might have those mixed up but the PCM is powering up from his description.

He said he has the PSI harness. Maybe injectors are clogged but to have all clogged would be a surprise to me.

Car had a engine fire which could have damaged them however as I read it he has different injectors in it now.

As always it's probably something simple like a loose ground.

A friend of mine had a problem with his LS and PSI setup cranking and not starting. Turned out where the 2 grounds bolt to the rear of the head the bolt was a touch too long and bottoming in the threads. The bolt was tight but the grounds were loose.