rvega022

I have been having problems starting my 1986 IROC-Z 305 TPI. I have to crank the engine 2 to 3 times to get it to start. I checked the Ohm's on the cold start injector and I only get 4.1 Ohms and on all the other injectors I get 16 Ohms.

Since the Cold Start Injector is just another injector, it should be bad. I'm I correct?

Can anyone give me more information on trouble shooting a cold start injector?

irocuroc

the cold start is an on off solenoid with a nozzle. It is a low impedance coil and should be 3 to 4 ohms. IT IS NOT AN INJECTOR it does not pulse just opens when the cold start switch is commanded to do so from the ECU . There is a cold start relay and a temp sending unit ,, check them by seeing if you have 12 volts at the valve when cranking with a cold engine.

rvega022

irocuroc, where can I find the cold start relay?

vetteoz

iTrader: (13)

Standalone system independent from ECM control.Just a switch and the injector
See
http://www.austinthirdgen.org/mkport...ine_wiring.gif

No relay
When cranking , power goes to the cold start switch located at front of intake then to injector.
Make sure you have 12V in/ out of the switch when cranking cold engine.If not switch is kaput
CSI switch shown to left of one circled

LAFireboyd

iTrader: (3)

You circled the coolant temp sensor. The cold start injector switch is the large one to the left of the coolant temp sensor. Edit: Ah... you did mention it's the one to the left of the circled one... I missed that when I first saw your post.

The cold start injector switch is a temp "sensor," similar to the coolant temp sensor or a fan switch. And when the engine temp is below 95*, the switch triggers the cold start injector, actually called the cold start injector valve.

vetteoz

iTrader: (13)

Couldn't be bothered making new pic

rvega022

guys thanks for the info.

It appears that when I was rebuilding the TPI I made a false connection. I disconnected the switch cleaned the terminals and reconnected, everything is working fine now.