Coolant temp (EFI) sensor may be the issue . Inexpensive part

What was your problem. Glad it helped you.

The bias voltage on these older GM O2 sensors should be around 450mV KOEO and on this system because the heater circuits simply are turned on with the ignition and therefore should start to move towards 100mV with the ignition on not running. Turned out both rear sensors are dead anyways. Thanks for your support.

I was watching video I never thought of the coil it fiers when let go of key.trys to crank up but thanks allot.

I'm using a Snap-on Verus Edge tablet

No I didn't as I know the distributor was replaced and once running the cam sensor offset was at 0 degrees but you are correct the distributor gears wear out and throw out the sync between the rotor and tower causing an abnormally large air gap and weak secondary output leading to random misfire.

Try changing your engine coolant temperature sensor that was the problem in my 98 s10

No the ignition control module that was under the distributor cap of the throttle body systems did but this ignition module is a transistor controlling the ignition coil.

Nooooo it’s right beside the ignition coil that’s the problem

That code is not a failed sensor and to be honest a failed cam sensor won't cause a no start condition. If you removed the distributor then you likely have it out of time. Pull number one plug, turn the engine until you feel compression building in the plug hole then line up the timing mark to the top dead center pointer. Remove the distributor cap and check that the rotor is lined up to the appropriate tower. Also make sure the plug wires are on the correct locations. That code is typically caused by a worn distributor drive gear..

Check your frame ground. There is a heavy ground on the lower right side of the firewall between the body, frame and engine. Since the fuel pump is grounded to the frame a poor frame ground will affect it.

@@PhillipBailey it’s a 6 cyl 4x4 4.3l. It also has a new coil. I’m about to check the terminals now on it. Appreciate your fast response

@@PhillipBailey also just hooked up a test light to negative and put it into the coil to double check the coil. I wasn’t visually seeing a spark connect from the light to the coil but the light would flash if I had it all the way in and was cranking over at the same time but couldn’t see the spark

@goodtripsonly according to my info a 2003 S10 with a 2.2 4 cylinder uses waste spark and does not have a distributor.

@@PhillipBailey it’s not a 4 cylinder. It’s a 6 cylinder 4.3l

@goodtripsonly ok then. The sensor in the distributor is the cam position sensor and it will not cause a no start. Here's what I would recommend to try... 1. Turn ignition on and listen for the fuel pump to run for about 1 second. The MIL must also come on in the dash and Stat on. If neither work check the fuses that power the PCM. If they are good then you will need to confirm the powers and grounds to the PCM. Ok go to 2... 2. You said you have no spark at the coil wire. Connect a test light to ground and backpin the white wire at the coil with the ignition on the light should light bright. If not backpin the pink wire key on. If it lights then replace the coil. If the test light turns on on the white/black wire have someone crank the engine over. The test light must blink indicating that the primary side of the coil is being switched on and off through the ignition control module. If it blinks and you have no spark from the coil replace it. If on steady 3... 3. If a scanner is available access engine data and watch for an RPM signal cranking and injector pulse width. No RPM and injector pulse it's likely a failed crank sensor or wiring. RPM and injector pulse 4... 4 at the ICM by the coil a graphing volt meter to the control wire backpinning the white wire. Cranking you should get a 5 volt pulse to trigger the ICM. If you have a pulse then you have a failed ICM. No pulse you have a failed PCM or wiring to it. There are a few other things that could be checked such as does the fuel pump run during cranking, do you have injector pulse. Other things like no fuel pressure will cause a no start but won't cause no spark.

Check for ignition power and ground at the coil. The pulse is a 5volt signal from the pcm. If you have those then the coil is bad.

When it won't start I gather it's cranking ok. You need to figure out at that time what is missing ie spark, injector pulse or both. If you have no spark and no injection pulse could be a failed crank sensor. If you are missing just spark it could be a failed ignition module. Is there an RPM signal on the scanner? If you have both spark and injector pulse check fuel pressure.

Try changing your engine coolant temperature sensor that was the problem in my 98 s10

What was the problem

Also, engine cranks but no codes..

Yes a coil can fail with no warning. Do you have spark at the coil wire? If so check cap and rotor. If not listen for the fuel pump to prime when tlyou turn on the ignition. Bump the starter with the key and listen for tge pump to rerun. If it does this indicates the crank sensor is sending a reference to the pcm. Does the data indicate rpm while cranking? If so you may have a failed ignition module. You need a graphing meter to check for the 5volt pulse to the ignition module. Good luck.

You need to check it when the problem is present. does the fuel pump run on key on for the prime cycle? does the MIL turn on with the key? check fuel pressure, spark and injector pulse...what do you have to do to get it to start?

@@PhillipBailey I do have spark and my fuel pressure was at a 48 the other day when I checked

⁠@@PhillipBailey also I thank I found a ground wire that comes from the bottom of the back driver side of the engine right by the headers that is striped that is not connected to anything

@302chris9 needs minimum 55psi fuel pressure. Sounds like a failed fuel pump. Try spraying some carb cleaner in tge throttle body see if it will run. Could also be a bad fuel pressure regulator but you said you replaced that already.

@@302chris9 that could be the frame ground and may affect the operation of the fuel pump.

If you have no spark from the coil it's not the distributor cap or rotor. Does the check engine light turn on with the ignition switch? Does the fuel pump prime? Does the PCM communicate with a scan tool? Codes? Does the PCM read an RPM signal while cranking?

@@PhillipBailey the fuel pump does prime. One code only, p0442 (small evap leak) I haven’t checked rpm on a scan tool but I don’t see the tacometer move when cranking

Yes check engine light comes on p0442

@saulguel5404 the gages may be frozen during cranking. Have to watch rpm in scan data. I'm sure the p0442 is unrelated.

@@PhillipBailey should I replace the ignition control module,

I see three wires to the coil none is purple and 4 wires to the module again none is purple. What year and engine? What's the problem with the engine. Sometimes an aftermarket car starter is tied into the white wire as that's a tach signal. Does it have an aftermarket car starter?

@@PhillipBailey at 9:32 you can see the purple wire going to drivers side from the ignition coil harness

@theoholcomb50 as I said that's the tach signal wire for an aftermarket car starter on this truck

It's a process of elimination, scan for codes, review data for failed in range sensors, check fuel pump operation, fuel pressure, spark at plug, spark at coil, injector pulse and fuel delivery. Could also be a mechanical engine problem like jumped timing chain, stripped distributor gear or contaminated fuel.

It will take a bit of cranking to build oil pressure especially if you have not started it for several hours. You did mean oil pressure not fuel pressure?

It was towed in as a crank no start but the coil could cause an intermittent no start or stall condition for sure.

@@PhillipBailey thanks for the reply, been chasing the same issue for what seems to be an eternity. Crank sensor shimmed, new plugs, wires, cap, icm, cam sensor, coil getting power, random no spark. Coil has been changed, but i think its the next to try.

There are lots of causes for a crank no start condition