Danger_Dorn

Hey guys I was creeping around and read almost every thread I could but that didnt really help much. I was driving around with my new motor and had to speed up to get on the highway. As I was speeding up I hit boost. I wasnt watching the boost gauge but it was probably about 6 psi and all of a sudden I felt a jerk and started bogging. I pulled over and saw nothing out of the ordinary.

Thought that it must be a pipe off but I have tightened all of my IC piping to where it mushrooms so I know thats not leaking, if I unplug my cylinder 3 coil pack it does not change the idle and there is fuel in the cylinder when I take out the spark plug. I took the coil pack and spark plug and put it on the valve cover and it sparks good and blue. Unplugging the maf does no difference, unplugging the tps makes it run crappy, if I unplug the injector and coil from 3 it drives ok just sluggish. I didnt think it was the maf because it just happened for no reason. I will try cleaning the maf, IACV and pulling codes but I'm at work right now and cant.

Info: s14, internally rebuilt redtop, new full WS harness, CXracing IC, new bkr7e spark plugs gapped to .28, Walbro 255 w stock FPR.

ultimateirving

Round two Dorn

So the coil is sparking but it is jerky and bogging when in boost.

Also the fact that your idle didnt change when you unplugged coil pack 3 means a dead cylinder... But you said it sparks when the plug is out. This leads me to think your coil is worn out. I had a bad coil and the car would drive (not great i should add) but when i hit boost it would break up and struggle so much..
I found out my number one coil could pump enough spark to fire under low load, but under boost it wasnt cutting it.
Try swapping ur #3 coil with another, and then run the same idle test and see if that cylinder is still dead.

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Danger_Dorn

Thanks Irving for once again chiming in lol. I'll give this a shot when I get home. I forgot to mention my center valve cover bolt is broken off and I had oil in my 3rd sparkler hole. I also was suspecting a leaky injector since the car was running rich like 11 on the UEGO even at idle. I hope I can figure this out since its my DD and I LOVE running on 3 cyls and potentially warping the crank

AJZax

for diagnosis, try what irving said. Switch coil pack #2 to #3 or something.

also clean oil off the spark plug tube
pull plug, clean it, check the plug gap.

Mine was starting to poop when it hit 4500rpm and enough open throttle to have liek 14psi or so, but would rev to 5 perfectly fine on super light throttle. I put Z33 packs on and bam! fixed.(also cleaned, and re-gapped plugs, they were at like .035 and I regapped em' to .029 lol

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Danger_Dorn

Yeah i'll give that a shot. I was just confused and ruled out the spark issue since it was a blue spark when I had it sitting on the valve cover. I think spark isnt the issue

Danger_Dorn

Ok just went and tested a few things. Switched coil packs 2 and 3...motor runs the same when I pull the plug. The coilpack that was in cyl 3 works fine in cyl 2. When I unplug the MAF and wait a min it goes into safe mode. I am getting 12 volts on the 3rd coilpack harness plug and on that injector plug. So I really am out of ideas. My spark plug was black so could I be over injecting? Or have a leaky Injector? I might try switching injectors next...

Kingtal0n

Do a compression test on that cylinder

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Danger_Dorn

No compression test avail...but I did just go switch everything from cyl 3 and cyl 1 only to find no difference. It makes it run worse so I'm out of ideas. It has to have something to do with that 3rd cyl. I'm about to pay someone to pimp my ride unless i can figure this abortion out

Kingtal0n

rent a compression tester free from a local discount auto retail store

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Danger_Dorn

Yeah I'll borrow one from a friend sometime probably this weekend. BTW when I switched the injectors the 3rd cyl was black inside so I KNOW i'm getting fuel so maybe its time to dig deeper into spark. The motor is freshly rebuilt so theres no reason for there to be no compression...

Danger_Dorn

Update: Still no comp test but I did take a screwdriver and listen to the injectors. All are clicking like described. I even unpluged and pluged it in to note the difference and its definitly clicking and my whole cyl is black when I removed it...there goes my clean fresh head Anyway I am getting 12V to the coil pack connector is that right? I know there is a "E + -" I imagine E is earth or ground + is ecu voltage in , and - is....feedback? Ill search that. SO now I def. think its the coilpack but nothing changes when I switch them...I need a spare to test with.

Danger_Dorn

Now I ran the motor and did all kinds of playing and here is the results.

All injectors are clicking the same. Cyl 3 is sparking and I am getting 12 V from the + but no way to check the - while its going. IF i unplug the injector with the coil still pluged in i get a distic "TINK TINK". Not sure what that is but it happens every time. Detonation? Idk. You tell me lol. If I unplug both injector and plug and go around the block the car does not backfire but its sluggish. If I leave both the injector and coil plugged in when I drive it, it wants to go but stumbles or backfires and is really jerky. And last but not least...if I switch coils 1 and 3 nothing changes. Now the car did seem to idle better when the injector and coil were plugged in but I got that "TINK TINK" so that scares me not knowing what it is and for now (being its my dd) I just leave it unplugged. So please someone tell me is going on? The plug was black but not smashed or anything and gapped to 30. SO, I think the verdict is over injection but I will have to try switching injectors around tomorrow see if I can cause misfire on a different cyl. If not I have no idea maybe valves.

ultimateirving

You can try taking off the fuel rail, Its like two bolts. Then prime the fuel rail with the ign to on.. See if any fuel leaks out of cyl 3.

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Danger_Dorn

Could it be overfueling without leaking? Ill do this test tomorrow probably but I just am looking at all possibilities right now.

Its not MAF,tps, or cooolant temp because that would affect all cyls.
Its not CAS because it does spark.
Its probably not ignitor plug because it sparks blue/white but it could be weak. Its not the coil pack because nothing happens when i switch them.
And its likely not wiring because I have a new WS harness except for the coil wiring sub harness but I looked that over and its fine.

Any Ideas? Thanks alot for the help guys

sil80dude

I think its an injector dude. My friend had pretty much the same problem and he changed out all 4 injectors and it ran perfect. Their are a few types of injectors that can be used in the sr's. (yellow subaru 550s , turb rx7fd's i think. You could pull the injectors and have them tested at a shop for pretty cheap. Another thing you could try is too pull the injectors and check that you didnt loose the little O ring at the base. Also lube them when you put them back in so they get.a nice seat. They can be tricky to get a good seal. Hope this helped.

Danger_Dorn

Thanks man I appriciate it. I'll give em a shot

Danger_Dorn

An excellent progress in technology

Posting to get in the classifieds I see

Danger_Dorn

Just went and pulled the fuel rail. No leaking when the pump primes. Switched injector 3 to injector 1's spot still no difference. Still has that loud pop after reving when 3 is hooked up and boggy with backfire.

Danger_Dorn

So this will be fun tomorrow...yay

Mark Slide Squad

I had the same problem like 12 years ago on my redtop SR. I noticed that you said the thread for the coilpack bolt hole on the valve cover is busted. Mine did the same, and the coilpack wasn't making a solid contact to the plug and was causing a misfire. I fixed the stripped hole and the problem went away.

Also check to make sure that you don't have a leaky intake manifold gasket. You said the motor was just built. Sometimes if you don't torque the intake manifold properly it will leak air and then you get the problem you describe. You can spray soapy water around the area where the head/intake manifold meet. If you have an air leak, the soapy water will start to bubble.

Check your coil pack harness as well to make sure it's not damaged. When they get old, the wires tend to fray and it can cause problems and short out too. Make sure the coil pack harness ground cable is good and secure too.

Check your MAFS to ensure it's clean. Spray it out with electrical contact cleaner. If the heated element inside gets any oil or grunge on it, it can also cause that issue. People will re-oil their K&N style filter with too much oil and it sucks the oil into the MAFS which will make it run like garbage. Only way to fix it is with cleaning the MAFS internals with the aforementioned electrical contact cleaner.

Danger_Dorn

Thrown rocker arm on cyl 3...

Mark Slide Squad

Yup, that'll do it for sure! Lol. Sucks, but now you know the issue. There is only two reasons they throw rocker arms, over revving, or the valve shims aren't correct. Did you spec out the valve shims to ensure they are the same height between the two valves when you put the motor together? People often forget this step, or simply don't know about it or realize how important it really is.

Danger_Dorn

Negative I did not do this but here is the catch....I dont have a tool to measure that so...yeah.

Danger_Dorn

I do beleive air in the lifters can do this also. The shop that redid my motor said they are all .300 but clearly that may not be the case. I do not have the money to go back and buy 16 of dem bishes

Mark Slide Squad

You can make your own tool to measure the height. It's SUPER important, I would highly recommend doing this on all your valves. It will save you the headache of breaking something or having excessive wear on your valvetrain. You can make your town tool here using an old hydraulic lifter HOW TO: Measure Valve Shim Heights (Pics) - SR20 Forum

As far as air in the lifters is concerned, you don't need to buy new ones. Just pull out the original ones, submerge them in a container filled with oil, and then use a very small allen wrench through the top hole and press down. You'll feel the allen wrench fit into the plunger (gotta get it perfectly centered) and then you can push down on the wrench and you'll see the air bubbles come out. Keep doing it until the air is all gone, then when you take it out the container of oil, make sure to never tilt the lifter on it's side or upside down as air will get inside again. Reinstall the lifter and do this to the other 7 lifters.

The 16 valve shims of what you have should be ok of what you will need. They are cheap if you need to buy more, they are like $2 each at the nissan dealer, same shims as the SR20DE Sentra SE-R and Infiniti G20. They come in different thickness' though, so that's why you gotta measure and see what you need. You will only need to buy the flat shim, not the slotted shim, as you only need to match the height of the other valve. Make sense? With a brand new built motor, I can't stress how important this is!

Danger_Dorn

I bled all of my lifters on both sides last night without removing timing chain...not messing with that timing bs. Now the only problem I will have is initial start due to low oil pressure in the lifter. I had this problem before and didnt know the problem so I took it to a shop. They put 200A through the starter and it fired right up lol. From what I have read all the shim and guides in a particular motor are the same height. I have read this multiple places so that once you measure one then your good.

cotbu

The lifters are hydraulic but not self bleeding,You bled the lifters, done! Why do you think not having oil pressure to the lifters will stop you from starting your car? Is there some other lifter you're talking about or are you getting your info from somebody that knows more than I! It sounds stupid, don't you think? At least every time I read it, it does!

JUST THINK!
What I can tell this from your posts. Your car does not start on the first crank!
Your battery is weak!

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Danger_Dorn

It does when I was driving it all this week. Maybe its because it sat for so long before. Idk. maybe I'll try jumping it

Danger_Dorn

Well the shop I took my car to the shop before and all they did was craaaaaaaaank the damn thing so idk. I have a fully charged optima redtop

Mark Slide Squad

Ok, please take some friendly advice as I am trying to help you out here. I have been working on SR20's since 1998 (no BS) and have put together many SR20's since that time. If you take a look at the factory FSM from Australia, it will show you that all shims are NOT the same. They come in about a dozen different thickness'. The top of the valve will NOT be equal height to all other valves on the head, period. Due to tolerances in machining of the height of the valve, the valve spring retainer, and the valve seat itself, the height where the shim sits will vary. Whoever told you that all shims are the same height clearly doesn't know wtf they are talking about. Please do yourself a favor, DOWNLOAD the factory service manual. Study it. Read the section of measuring/setting valve shim clearance. If you don't understand it, I would recommend taking your car to an experienced shop that knows about SR20's.

And your car will start fine with the oil pressure in the lifters if you bled them, not sure what you mean with that part. As long as your battery is ok, the lifters won't affect the car starting. Zilvia has so much bad information on here, it's terrible. One person says something, and all of a sudden everyone believes it. If you don't believe what I am telling you, again, look at the FSM. If your valve shims aren't set correctly to each other, you WILL break/crack/throw a rocker arm, cause severe valve train wear, etc. Good luck.