https://www.thirdgen.org/forums/v6/2...st-valves.html

I'll get Dale to comment on here.

 

In by request.

I posted on here many years ago word for word what my GM/Helms manual says. It is 1.5 turns past zero lash. I know chiltons and haynes says 3/4 turn.

Now, it doesnt say what lash is. So what is lash? What Ive learned is that lash is UP DOWN movement, NOT SPINING!!!! By the time the pushrod is done spining, the're to tight. So odds are, you have valves sticking open. you can somewhat check this by using a compression guage. But it doesnt take into effect the oil pressure pumping up the lifters.

Hopefully the cam is not rounded off as mine kept doing. So while your spining the motor over adjusting them(or checking compression). Have friends, whoever. Watching to make sure all the rockers tilt. If one doesnt tilt, your fubar. You should also check compression anyway after replacing a head gasket. Check your oil to, make sure the gasket took and is not leaking antifreeze into the motor.

:edit: and search aint f-ing working. If you need me to type it again, scan it, whatever. PM me.

 

Searching via google, I found the thread.

https://www.thirdgen.org/forums/v6/2...ods-final.html


Tomp is correct about the "lash" definition. The play between two parts. Not spinning.

 

OK I get the right way to do this now. Just like the book except with 1.25-1.5 turn after what is described as 0 lash in the book.

 

lash by up-down movement, not spining the pushrod.

Also, before you do this. Do you have a vac leak? What are you getting for compression on all cyls?

I am guessing you have them to tight already.

 

I am hearing a leak from underneath the manifold so it is either an injector (now o-rings on all of them) or I think that it is from that hard tube that goes to the manifold.

I assume that the rockers are tight already since I did the 3/4 turn. I'll just back them off again adn adjust from there since I did the 0 lash by spinning method.

 

so its a vac leak? Could be the intake gasket didnt seat all the way.

 

I put new gaskets on both heads and also put silicone on the front and rear of the intake b/c I wasn't sure if I was supposed to or not. I made sure that it was seated well (rubber mallet) and did all of the bolts to torque in the right order.

 

Well Dale, I would have to say there is a fine line between what you and I have posted. I never posted to tighten until they stop spinning, but rather where you feel slight resistance (the pushrods would probably have .010" play at that point), then 5/8's more. The book says 3/4 turn more, but as you kind of said, it's better to be loose .

I guess for someone green, your method perhaps would be better simply because my method could be interpreted differently depending on the reader (and how "resistance" could be different between two sets of hands).

I have had no problems adjusting valves the way I do (and not just on the 60* motor), so if 2.8rs's valves are too loose because of following my directions, I apologize. Everyone has different methods of achieving the same result, some methods don't work for everybody .

 

Well, if there was an exact way to do everything, we wouldn't be here!

 

Thanx

 

I redid all of the valves and the car runs much better. There is still a little but of missing in the high RPMs, almost not noticeable. I only did 1 turn after 0 lash so I think that I will go back next weekend and add an extra .25 turn to each valve. Also is it alright is each rocker stud isn't showing the same amount of thread? There were a couple that have fewer threads showing but not much. Thanks for the help guy, it turned out that the problem was from cylinder 3 I believe. That plug was fouled again. Thanks again.

 

The car WAS running better. I went out with some friends and the car got worse as the night went on. Now I am getting code 13, 32, and 42. Code 32 is explainable since I took out the EGR. Code 13 is O2 sensor or poor connection to the TPS or it is sticking. Code 42 is electronic spark timing, The description is defective ignition module.

I am about to go out of my mind. All of this is draining my money. I'll check any connections that may be bad. The car is running rich again, I bet another plug is fouled, the O2 is bad (not that old), this is getting old.

 

Weird. I origionally said that you have a timing problem, not the valve train. You are going to need some more diagnosis and figure out what's up. If it happened after the head removal, them it's something you missed during reconstruction. It's tough to diagnose w/o being there, but we will get things figured out.

 

It's actually running much worse than it was than the last adjustment. I'll pull the plugs again to see if any are bad. I also just did a quick inspection of wires and such. Everything looks like it is right. Now that I think about it the runs good for a couple of minutes until the O2 heats back up. I may just go get a new one and possibly an ignition module.

I went and pulled the plugs again. Guess what, cyl number 3 is fouled again. So now I am wondering if the injector is fubar, could that cause the missing, running rich, ect? Should I get just one injector or get six all new ones?

 

Long weekend for me, just got back to the boards.

Sorry to hear about the trouble! Sounds like #3 is having problems. If you want to troubleshoot it without buying new parts, swap #3 injector with #1 and see if the plug fouling is repeatable. Have you checked your fuel pressure?

I wouldn't get a "new" injector. Get some junkyard units. I mentioned before which injectors to get.

If the car was running good after the last valve adjustment then I'd leave them be and focus on #3. If its dumping fuel then the rest of the car will be lean, causing all sorts of problems.

 

I went to Advanced Auto Parts today and they wanted about $86 for one injector which they didn't have. As it was explained to me Chevy put a little different injector in 89, its different from 88 and before which I don't understand. After seeing the price of just one new one, them not having one, and me being able to get 6 used for less, I think that I am going to go to pick n' pull tommorrow after work and hopefully get some.

The only questiion that I really have is that most of the F-bodies at the local junkyard are 3.1s. I know that the injectors will work and that they are bigger (not by much) but will 3.1 injectors make me run rich? There might me a 2.8 in the junkyard but its like a 86 or so, one of the first years of MPFI.

Also what do you guys make of the codes for the ignition module and O2 sensor? I figured that the O2 could mess up from running rich but the ignition module??

On Sat when I readjusted the valves the car was running probably 90% but I was happy for the weekend and it just got worse as the night went on, I could barely go up hills and was about to pull over and call for a ride home.

 

You can use any 3.1/3.4 or any FWD 3100/3400 injectors. All were 17lb/hr. The main difference between your 2.8 15lb/hr injectors and the before mentioned, is the head design. 15lb/hr are pintle, 17lb/hr are disk. While the disk are bigger, they also meter fuel better at low fuel rates, making them better overall than the 15lb/hr pintle style. Pintle has one big hole for fuel, disk has 6 small holes. Not to mention disk injectors have much better spray patterns.

The ignition module and o2 codes could have been thrown because it was running lean. Lots of o2 could be poor burn (ignition) or faulty o2 sensor. Fouled plug is a bigger indicator of a problem.

 

I'll get the injectors tommorrw and will have to put them in on wed and we'll see what happens.

 

I got some 3.1 injectors today thought I won't be able to put them in till tommorrow hopefully. What I wanted to know is is there anything that I can spray on the injector to clean out the dirt and grease that was on my hands (I had to pull them off the fuel rail). Also how can I turn off my fuel pump besides pulling the fuse? Everytime I full the "right" fuse the pump never turns off.

 

easy way would be to pull the fuel pump relay. Its by the brake booster. Just pull the connector out of the bottom of the relay and you'll be guarrantied it won't turn on.

cleaning them, I'd use some brake cleaner. And make sure to lube up the o-rings with lithium grease or similiar non-rubber corrosive lube.

And make sure you measure the resistance of the new ones just to make sure you don't have a dead injector.

 

How do I measure the resistance. I have a digital voltmeter that I have used for the TPS.

 

It's ohms

 

OK...
Then what do I need to do and what equipment?

 

I got some 3.1 injectors and swapped them in. There is so much more power in the top end. The car feels restricted up to ~4500 RPM then its like I am spraying a little bit of NOS b/c the pickup all of the sudden is mads me smile on the test drive. I am still throwing codes for the ignition module though. I figure that is why the car feels restricted in the lower RPM now. The good news is that there is no missing and the motor is running nice and smooth now. Where is the ignition module and how do I go about replacing it. I have no clue where is it or what it does. It's code 42 BTW. Something about elecronic spark timing with a loose electrical connection, bad ignition module, etc.

I think that it is the ignition module. All of the connections are tight and everything else is hooked up.