Reasons for injectors not pulsing?? I only checked 1 w/ a noid light, but it only tries to start when spraying starter fluid. I just got HP tuners, is there a way to check the injectors with it??
It is a 72 nova, new PSI harness, 06 escalade engine, 05 ECM

 

connect the scanner with the ingnition on before you crank the engine. Look to see if you get injector plusewith, spark, and cranking rpm. Could be cam or crank sensor related. Have you turned 'vats' off in the tune?

 

I'll give that a try this coming weekend.
Yes, the vats selection is on "none"
thanks

 

Sounds good. If you live in the Illinois/St. Louis area I can help you out.

 

Crosstrain,

Make sure that the switched power wire coming from the back of the fuse relay center is getting power with the key in the 'On' position and the 'Crank' position. Please call us if you have any questions and we can walk you through the troubleshooting procedure. Thanks.

Jon

 

Thanks for all the help. I will try to check these things this weekend.
SmokingWS6, I really appreciate the offer. It may be a little far. I live in north east Indiana. I would have to trailer it, which I would be willing to do.
Jon, I may give you a call to talk me through it. Thanks.
I'll see how it goes this weekend

 

What next???

VATS is turned off.

switched power wire coming from the back of the fuse relay center is getting power with the key in the 'On' position and the 'Crank' position.

Had Jon at PSI look at the computer & he said he could not see why the injectors were not pulsing from looking at computer.

Checked the crank sensor & cam sensor wires going to the correct plugs.

I did find out my intake was missing the plug for my MAP sensor though. so I have to get 1 of those.

Does anyone know if you can go into the computer and switch on the circuit for the injectors to pulse? Just to see if they are working.

The guy helping thinks it is still in the computer because we have looked at everything else?

Any suggestions?
Thanks

 

Engine to frame ground wire maybe

 

Let us know when you get the MAP hooked up. Even though we didnt provide/program the PCM, I am more than willing to flash the tune onto a good core in order to eliminate possible PCM issue. Please give us a shout once you have tried it with the MAP hooked up.

Jon

 

We are also getting spark and crank RPM's on the scan tool. The injectors pulse 1 time, but that is it.

 

Thanks Jon, I will call you later today.

 

You're not alone! I'm getting the single pulse too. Good luck and if I find out what mine's doing I will let you know.

 

On my truck, the map sensor failed and wouldn't allow the injectors to spray enough fuel to start. May be something to check. You can post a pic of the cranking cycle from HPT VCM Scanner.

 

I did not have my MAP sensor connected, so I am sure that did not help. My intake is missing the MAP sensor. I am taking the 1 off of my truck intake this weekend.

Jon @ PSI has been great!! He is sending me another computer to try. This way I will know if it was a bad computer or something else. I feel like we have checked almost everything else, so I really think it is a bad computer. Hopefully I will get that by this weekend, and I can give it a try.

 

I got a MAP sensor

Current issues:
2 pistons not firing. the front passenger & the 2nd from the front on the driver side.

Ok, testing results for today:
1. Switched plug wires. Switched 1 that 1 knew was firing to the 1 that was cold. No change.
2. switched coil pack. same thing, switched for 1 that was firing. No change.
3. checked spark. good spark.
so, at this point I pulled the plugs from the 2 that were not firing. They were dry. I thought maybe the injectors were bad.

4. put a noid light on the 2 bad ones. They onyl lit up 3-4 times. Put the noid light on 2 good ones & they were kept lighting up regular.

Why would the injectors pulse just a few times?

 

Did you check continuity in the wires going to the injectors? One side should be +12v switched so check continuity between it an the switched power source...the other wire check between injector end and the pin at the ecm...

could also swap injectors around like you did with the coils and see if the problem stays or moves

 

checking continuity is next on the list. I have to get a pin out or diagram of the ECM. I am going out of town, so it will be 2 weeks before I can check the continuity.

 

You will have continuity if you are gettin some pulses use a headlamp as a testlight to see if the wires will carry the current. A single strand of wire will give you a good continuity reading. I would check connections.

 

good point

 

Give me a call for the pinout. Thanks.

Jon
PSI