Should I check the resistance on the fuel injectors? Remember, this is an intermittent issue. Crops up once every 1 - 12 months. Engine purrs like a kitten.

 

Pick up a NOID light set. Keep it in the truck. Next time it doesn't fire, use the NOID light to see if the injectors are getting signal or not.

Here's one set: https://www.harborfreight.com/11-pie...set-97959.html

Harbor Freight also has a 25% off coupon for tomorrow, so that might make it $30 instead of $40. (Might - some lines are excluded, this one may be, I haven't checked, YMMV. TTE, BNI, etc.)

RwP

 

I just checked the resistance on all 8 injectors. The first six gave me 15.6 ohms. The 7th gave me 15.5 ohms. The 8th gave me 15.4 ohms. My cheapy multimeter has a .3 ohm inherent resistance. I don't know the spec for my 5.2L engine but they appear to be consistent. I don't think .2 ohms is anything to get riled up about.

 

Thanks Ralph. Questions:

1) Will the kit have a light that will fit my 5.2L injector harness?
2) Can I expect the light to go on even if my truck wont start?

 

Ha! Honey found me one coupon that applied. $8 off. Basically pays for shipping anyway. I'll check again tomorrow (with my luck there will be no coupons tomorrow).

 

Say @RalphP, I picked up the NOID set. For S&Gs I decided to test one of the injector circuits just to see what it looked like. She flashed on and off beautifully when started. QUESTION: Next time my truck conks out and I go to test, which injector harness should I check? Any specific one or all eight or what? And if light stays on what is my problem and if it never comes on what is my problem?

Thanks, Ed

 

Test any of them if it's not starting at all; you're just looking to see if you've got injector fire.

This is part of the "Let's eliminate what we can. What's left is what's wrong."

RwP

 

OK, Ralph (or whoever wants to chime in). Went to go pick up a pizza. I started up my truck no problem. Made it 500 feet out of my driveway before my truck petered out. Had my noid light kit with me so I checked each cylinder right where it died. All 8 cylinders flashed the same cadence. A flash about every 3/4 of a second. Consistent flash. Tells me it is getting a signal from the computer (from what little I know about noid light tests). But here is the strange part. I did a code check on my OBD1. Flash sequence as follows: 1,2,2,7,5,5. That's a code 27 which corresponds to: "Injector #x output driver does not respond properly to the control signal. ** "

** Check Engine Lamp (MIL) will illuminate when this code is stored

Now I've run a code check within the last few months and came up with nothing but I'm pretty sure the only time I did the code check was when the truck was starting and running fine. I believe this is the first time I did a code check while it was not starting. BTW, the check engine light has never come on when the truck peters out nor is there a check engine light that comes on once it is running again.

Current status: I rolled my truck back to my driveway. It still wont start. It's been about 2 hours since it crapped out. I expect it will start eventually. It always does. I'll probably check one more time before I hit the rack. If not, I'll try again in the morning. The frequency at which my truck craps out is increasing. Used to be once a year and now I'm down to once every few weeks.

I anxiously await your thoughts. Thanks Ed

 

The "12" is that you lost battery voltage to the PCM within the last 50 start/run cycles (no, cranking it and turning it off doesn't count).

If you HAVE disconnected the battery, that's ignorable.

If, however, you HAVEN'T ... there's a break somewhere between the battery posts and the keep-alive on the PCM.

RwP

 

I have disconnected the battery recently trying to reset the PCM last time the truck crapped out. Pretty sure that was less than 50 start/run cycles ago. My truck is used only a few times a week if that. I’m not concerned about the “12”. I’m concerned about the “27”. That is the code for a faulty output driver in the PCM.

???