Once I pull the valve cover do I have to replace the gasket with the harness in it ?

Is there a way to test the harness itself to see if it is good before I replace it ?

I did a buzz / cylinder contribution test and cylinders 1,5,7 are coming up bad.

not sure if its the harness or the injectors .. is there a way to test this before i start pulling out injectors ?

Oh yea... anyone have 3 good injectors they want to sell ?? ha
Thanks !

 

Gasket is reuseable as long as no pins are burnt.

Pull the connector from the outside the valve cover connection and look for burnt pins.
What color is your cps?
1,5,&7 is an odd combination.
Dont buzz or cct on a cold motor.

Injectors should ohm out like .3ohms (correct me if im wrong guys)

 

pins look fine...

what color is my CPS ?? I dunno
Crank position sensor ? ... cam sensor ?

CPS ?

Im thinking the connection might have came apart on the inside... cover not off yet..

 

Do you have any symptoms, or are you chasing test results? When you did the buzz test (cold buzz test is fine), did you hear 1, 5 & 7 buzz?

Don't pull any injectors. If you want to test the wiring with an ohm meter before pulling the valve cover, remove the flat 9 pin plug near the inboard center of the valve cover. Counting from the front, test the 3rd, 4th, 6th, & 7th pins against the center 5th pin looking for a reading of less than 2 ohms. If you pull the valve cover, look to see if the connector under the valve cover has come loose where it plugs into the valve cover gasket.

 

yes - this is what i am hoping for when i pull the cover.. ie 50 cent mod!
this is a best case scenario...
symptoms are hard starts...petal to the floor and only does 55...
wont spool turbo..
cylinder failure codes...oh and 1,5,7 did not buzz.. . but it was slightly noisy environment so the buzz could be weak but nothing like buzz the others made..

 

Passenger side is 1, 3, 5, and 7... so UVCH is very suspect. Here it the easiest location to test all the wiring and injectors in one hit: 42-pin connector over the driver-side valve cover.



D+ = Driver-side common and each injector is numbered.
P+ = Passenger-side common.

 

Sorry to say that it doesn't sound like the best case scenario. Pull the passenger valve cover and start the truck cold. See if those injectors are spitting any oil when it starts up. Then let it idle and warm up and see if those injectors begin to spit oil after it warms up.

If that happens, you've got worn injectors. You could try switching to synthetic oil or plugging it in for a couple of hours before starting as a band aid, but if that's what you've got going on it's time to start saving your pennies.

 

I apologize if this has been covered many times but I can't seem to find the procedure for testing from the 42 pin connector. In testing the injectors, am I simply measuring resistance across two points (e.g., the injector ground and the injector power, one example being #1 and P+)? If so, should the key be in the "on" position? ... with the engine off? What other tests can be performed at this connector using which pins?

Thank you in advance for your help.

 

You've got the right idea. You want to measure resistance in ohms with no key and battery grounds unhooked on both batteries. D+ is the ground or common for the even numbers. P+ is the ground for the odd numbers. Measure resistance between numbers and ground. They should be less than 4 ohms.

 

I wasn't getting any reading on D+ and #8 or P+ and #1 when I tried this afternoon but I didn't disconnect the battery grounds. Although I don't think it will make a difference but for the "-" sign, I also had the probes reversed.

If anyone else has guidance on other tests that can be done from this spot (e.g, glow plugs), that would also be appreciated. I can't seem to get the darn valve cover harness off.

 

Don't matter if you have probes reversed checking resistance. (this part confuses me-> Although I don't think it will make a difference but for the "-" sign, I also had the probes reversed.) It is telling me your not using the meter correctly?

Put the meter on OHMS and stick any probe in p and the other probe in 1. what is the reading? IF none then the problem is downstream either the wire harness chaffed , UVCH connector or UVCH .

You really need to get the connector off on that valve cover. Because that is going to be your next step anyways. Either checking resistance at the connector or pulling the cover.

 

Glow plugs can't be tested from the 42 pin connector, but assuming you have CA emissions, which uses a glow plug control module instead of a relay, any glow plug problems should throw a code and set the SES light.

 

The whole process is in a link in my signature (I added it recently).

 

Sorry - I should have clarified. It's a non-California truck - I have a glow-plug relay (no GPCM).

 

You might be right here. And that is what I was trying to figure out in asking for instruction.

The truck generally drives OK, but sometimes suffers from a bit of a hard start up and what I perceive to be a general lack of power so, in addition to the other testing I have done, I was trying to see what I could learn from ohming out the 42 pin connector.

I am getting no reading, but since the truck generally drives OK, my sense is that the problem lies with my meter or the way I was taking the reading. To clarify, I was probing the female side of the 42 pin connector. I hope that's right.

Trust me - I have tried every password, magician's trick, and double secret handshake to get that valve cover harness connector off. I've watched woodnthing's video and solicited help via PM from other experienced members. I'm either not strong enough or not pressing on the right spot on the release tab.

As I may have noted elsewhere, I don't think the VCs have ever come off on this truck (I'm the 2nd owner).

Thank you very much for all of your feedback - it is appreciated.