Running Issues, Running Lean, etc

[DuoWing]

Well the weather is getting warmer and I'm back at it. I still cannot seem to get this POS running right. I hope someone can help, also if anyone lives around me that can come help me with this thing I'll be more than happy to pay. I was going to make a topic for it, but I'm not sure where I should put that.

 

Anyway quick background on the car/motor.

99k L28ET that came out of my 83' 280ZXT automatic.

 

Motor was swapped into a 76' 280Z with a 5-speed, fidanza flywheel, ACT Street Performance Clutch kit, head was switched out for a P90 from a P90A with a non-turbo A cam. Redid oil pump, timing chain, tensioner, water pump, new alternator, etc. Basically a rebuilt motor save for the bottom end. Using an egr-less N42 intake manifold that's been shaved and polished as well, MSA 2.5" turbo downpipe, and I think that's it.

 

Running this is a 1986 Z31T ECU with a Nistune board. This setup ran perfectly when the motor was in my 280ZXT.

 

I've been trying everything to get this thing running right, I've checked and see that I have spark to all cylinders. I have fuel, at one point I thought injectors were possibly clogged or messed up pulled the rail and hooked up a fuel pump. Also ran power to each injector individually while the rail was pressurized. None of the injectors leaked, and their spray pattern all matched each other pretty closely. I put a noid light on each individual injector clip while running and I'm showing that all 6 injectors are getting signal. I've pulled the valve cover and checked the valve clearances they were all off, readjusted them. Need to recheck to see if they're still in spec.

 

Did a compression test and got:

1 - 135

2 - 130

3 - 135

4 - 135

5 - 135

6 - 130

So that seems ok.

 

Checked the timing today and at idle it was pretty much spot on at 20* before TDC.

At best I'm sometimes seeing vacuum sitting at -15 mmHG. The needle does not sit steady and jumps alot, I have a video to show. Put my wideband on and I'm seeing what looks to be fairly lean at idle, really lean when warming up and the timing is super advanced, close to 40* before TDC. Not sure if this is correct or not. When removing oil filler cap I'm seeing little to no difference on the wideband, vacuum gauge, and I'm not even hearing really any change in the motor.

My needle on my fuel pressure gauge vibrates like crazy I don't know if this is an indication of anything? When it's doing the priming sequence it doesn't vibrate, but vibrates rapidly while running. Pressure might need to be adjusted as it is sitting pretty high at idle. Around 40psi.

 

These videos came from my phone, so the sound isn't the best. The car seems to be almost running lean even at higher RPM.

I don't know how to insert youtube videos right onto the page.

http://www.youtube.com/watch?v=Fzs9gQaHoQk

http://www.youtube.com/watch?v=E5Zu9xJ45M0

 

I found a spot around the throttle body that seemed to respond to spraying brake parts cleaner all over it and I noticed the wideband would begin to read a little more rich when loaded up with brake parts cleaner.

 

Any suggestions on where to go with this?

 

Like I said if there's anyone around the Cleveland area as well who could potentially help me, I'd be willing to pay. I've been wanting to get this car running right so bad.

 

Thanks guys.

Edited March 22, 2011 by DuoWing

[Pharaohabq]

I'm not real certain about this, but to me is really seems like you've got a bad vacuum leak. the running lean and enriching when you spray brake parts cleaner (Bad stuff to burn btw, some of them give off super poisonous benzine when burned)

 

Separately, did you change the fuel pump when you swapped the engine? is it possible you don't have high enough fuel pressure?

[sweetleaf]

Make sure to fix all your vacuum leaks. I would also check the fuel pressure.

[DuoWing]

Forgot to mention about the fuel pump. I did change it out, I changed it to a Walbro 255lph or whatever it's called or at least supposedly it is. I bought it through ebay, but I'm not 100% sure that it actually is a Walbro...

 

I'm thinking what I'm going to do is try and make a boost leak tester. I'm going to remove the maf and cap off the rubber boot and then get some rubber tubing and a cap and cap off the exhaust, and just use like a bike pump to slowly pump air into it and look for leaks. I believe I read to use a mixture of soapy water and then that way you can see it bubble up around the leak? I'm really hoping that's all it is. Another thing I realized was I never sprayed around the brake booster or it's lines. So there's a possibility of a big leak there.

[twofouroh]

Umm, it's not benzene - - It's phosgene - The chemical weapon - - - That kills you - - NEVER use brake cleaner around flames, or to clean/prep for any kind of welding. It can KILL you. I don't even keep the stuff anymore. Anything it can do, can be done with charcoal lighter, or carb cleaner. I like my dangers up front and obvious. I don't care if they're flammable, it's an obvious, easy danger to minimise with proper handling precautions. A lethal dose of phosgene popping out from under a rust flake that had BC soaked under it, and now I'm a foot away heating it with a torch - is not. There are some good first hand testimonials about this, and burning off zinc, online that will make you think twice before using that stuff anymore.

[DuoWing]

Well I'm back to give another update on this POS. Anyway I went ahead and plugged off the exhaust entirely and capped off the intake. I used a 5 gallon air tank to pressurize the intake and I was finding I couldn't get above 2-3 psi. It was bleeding off so fast. So I went about finding vacuum leaks and found a bunch. Fixed all of the ones I could find and now I was able to actually pressurize the intake up to 6 psi, I didn't go much beyond that for fear of ruining something. It wouldn't hold, and would still bleed off. I found little things like where I capped the intake to be bleeding off a little which was no big deal, a little bit of bleed off at one of the mounting bolts to the downpipe, etc. Car still ran like crap, but did seem better. Still low vacuum though. Thinking I must have messed up the intake gasket I went and redid that, gasket had a few signs of where it could maybe be leaking, but I feel like I was really trying to stretch and justify it. Changed out the gasket anyway and put it all back together. Pulled the distributor out so I could get to the last bolt with my ratchet easily. So now I have to figure out timing, but anyway I can't get the car to start at all now. I found that my distributor cap is being held on by one screw. I don't know if this could cause the spark inside the cap to arc or bleed out causing ignition problems? Pulled the plugs and they were completely fuel soaked and black, they were breaking and bending too even though I was using a spark plug socket. So will put new plugs in tomorrow after letting the cylinders dry out a bit.

 

So a few quick questions:

1.) Can the dizzy cap being held by only one screw cause a problem? I can kind of lift and move the cap a little on the side where it's not screwed down.

2.) I have an aftermarket pump and aftermarket rising rate FPR and I removed the factory damper so my fuel pressure gauge shows the needle really fluttering when it does run(in one of my previous posts you can see this in the youtube video, is this normal?)

3.) Is there any way to tell if the oil pump is off a tooth or so? When the car was running I was able to set the timing correctly within the allowed adjustment of the dizzy so I think the oil pump was installed correctly.

4.) Any other suggestions from you guys?

[NewZed]

PCV system connected (crankcase to intake) or blocked off? Taking the oil fill cap off opens up the PCV system to atmosphere. No response when you remove the cap implies that it's already open.

[DuoWing]

The PCV system is still in place and connected. It has been a while since I checked the valve. Ill have to pull it and test it.

Edited July 28, 2011 by DuoWing