Hi Yotatech,
My truck is a 1989 3VZE 5 spd manual truck

My cold start injector ohms out at 3.5ohms

My cold start time switch reads within spec according to the FSM manual with the coolant temp.

The first test I did was pulling the CSI off the plenum, sticking it in a clear bottle and had someone crank the truck as i watched. no fuel coming out at all.

I figured out there was no power because I used a noid light on the CSI and got no power.

A few months ago I reworked the starter circuit to RAD4RUNNERS design due to the flawed one from the factory. I see that circuit is tied into this one.

I have continuity from the starter relay 12V load pin to B-W on my cold start injector

I have continuity from starter relay 12V load pin to B-W on cold start time switch

I have continuity between both wires on the CSI and time switch (G to G, and B-W to B-W)

However I noticed with the truck running and the CSI plug unplugged, and I put one lead on the positive side of my battery terminal, and the other lead on either one of those CSI plug terminals I get my 14V when running. Both terminals have 14V.

Are both terminals suppose to have that?

Thanks in advance for any help

 

Here is the Diagram I am looking at

 

No, if you're measuring voltage from the positive side of the battery to a point, a measurement of 14v(-ish) tells you the point is at ground, not 14v.

When your truck is running, ST1 is open. So what you learned is that both terminals of the harness to the CSI are at ground, which is correct. Look at the diagram; one goes to ground through the first coil of the Time Switch, the other goes to ground through both coils of the Time Switch. Your voltmeter draws (essentially) no current, so the 90 ohms or so causes no detectable voltage drop.

Does your CSI have continuity? (spec is 2-4 ohms) If you connect battery (12v-ish) to the CSI, can you hear it click? (There's also a flow test, http://web.archive.org/web/201311071...29coldstar.pdf, but it's kinda a big deal.)

Have you confirmed zero (okay, < 5) ohms to ground on the G terminal of the Time Switch? (has to be "cold'). Have you confirmed battery voltage to ground at B-W of the CSI harness when cranking?

 

Does your CSI have continuity? (spec is 2-4 ohms)
-Yes I checked it again today and have 3.4 ohms


If you connect battery (12v-ish) to the CSI, can you hear it click?
-Yes I applied battery voltage and I heard it click


Have you confirmed zero (okay, < 5) ohms to ground on the G terminal of the Time Switch? (has to be "cold')
-Yes, with the ambient temp at 49 degrees F:
-G terminal has 0.3 ohms
-B-W Terminal has 40.4 ohms


Have you confirmed battery voltage to ground at B-W of the CSI harness when cranking?
-When cranking I received 4.3V at the B-W terminal of the CSI harness to ground

 

That sounds like you have some resistance between the battery and CSI, enough so that when the starter cranks it's producing a ~8v voltage drop by the time you get to the CSI. That's all your wiring, since you've replaced the starter relay.

You could try disconnecting the starter solenoid wire (to get the starter from sucking up all that current) and repeat the voltage test at B-W when cranking. If the voltage comes up significantly, that tells you the current drawn by the starter is producing a big voltage drop between the battery and the CSI. While you're at it, try the stick-the-CSI-into-a-bottle test to see if it opens with the higher voltage.

 

i disconnected the starter solenoid and got 0.03V when trying to crank. all that happened was the truck did a single click

i also pulled the plenum off to inspect the wiring from time switch and CSI. nothing obvious like an exposed wire. however the connector wires look a little dried out

as for the CSI drip test, should I perform that after I get it working or should I go ahead and do that now? I do have a spare CSI i pulled from the boneyard incase this one ends up leaking

 

I'd be checking the temp sensor that tells the CSI to fire

 

Did you figure out the issue? I'm in the same boat with my 1988 EFI Pickup - also did the wiring fix to the starter relay and also have no power to the CSI. Brand new time switch also.

 

i put a noid light on the csi connector, '86 22re with the starter relay fix(not sure if it's the same fix as the v-6), it also has a new time switch... fwiw, in 65 degree weather the csi only fires for a very brief time while cranking.

 

I believe that's correct operation. I may well be wrong, though...
Pat☺