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78 DFI hybrid turbo passes "strigent" Texas emissi


Guest Tim78zt

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Guest Tim78zt

That's right!! Blown engine (70% leakdown on #1 and #2 cylinders) and all, it passed on the new load test here in Texas. What a motor!! In case you haven't heard all the inspection stations here have to have the dyno-style rollers for the drive wheels. Emissions are now tested under load (only 1100 to 2100 rpm though). Luckily there was no evidence of the usual cloud of blowby gasses during the test!! This is a very tough engine! It is the last year for my car to need this test so it's all downhill from here.

 

Now I just need to find another shortblock to get the power back!!

 

Tim78zt

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Congrat's Tim. We've been lucky here in Oklahoma. They stopped vehicle inspections circa 2001!

What did you ever figure caused problems with your engine, your rings? I remember you pulling your hair out a few months back.

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Guest Tim78zt

yeah, Len it was rings. That is also probably why oil pressure dropped so suddenly when it went "BANG"!! It never came back up to where it used to be. What do you want to bet the shop re-used the rings after they replaced the broken pistons in the first series of mishaps a year or so before this?

 

Tim78zt

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Tim, I hate to say it, but you are probably right on your statement. Recently, I have heard some bad things about them and some of it was from acouple years ago. I'm sure they CAN do good work though. Sometimes you think you can cut corners and not have it turn you around, but thats the price of speed.

On a lighter note, did you know we have formed a Zclub in Ft.Worth? Next meeting is on 11/14. Email me if you want some details.

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1100-2100 RPM on the dyno? Thats pretty messed up!

 

In CA where they do dyno testing (the high smog counties), its only 2500 RPM, and idle (limited to 1200 RPM max I believe), is non dyno. Putting a car in a high load/low RPM situation like that really sucks, that is worse than California!

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Dam! b_hand.gif

Tim that makes me sick! You mean just so the shop could save a few bucks they didn't install new rings? Especially so far along in a teardown! Kinda scary! I guess if we want something done right. We gotta do it ourselves! Hey I bet money, if they asked. You probably would have paid a little extra for your repair to be done right!

Regarding emmissions. I feel lucky yet somewhat apprehensive, as I work on my 280zxt. While fabbing and routing I/C piping. Charcoal canister in the way; so I removed it. Building up new Turbo DP. No need for EGR connection. So I removed it. Building my 3" exaust I build same lenght straight pipe as my Cat to exchange when needed.

Due to the unsure times we live in :confused: (along with Oklahoma politics). I've kept them intact to reinstall at a later date, when our laws will change. Which I'm sure hey will!

Len

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I doubt that they would put in the old rings after broken piston mishap. When a piston goes south the rings usually bust on the edges. The loud pop was detontation and took out your rings. I would definately try and find out what caused the bang and fix that before go on with another rebuild.

 

Either you are getting not enough fuel momentarly or incorrect igntion timing or poor spark is causing this.

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Guest Tim78zt

Clint, could the incorrect ignition be coming out of the DFI, like it is not processing correctly? Someone else had this trouble with their DFI and Accel fixed it. I'm thinking I should have my ECU checked.

 

Thanks for the help!!

 

Tim

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It is possible to be getting incorrect timing from the DFI if the distributor lockdown came loose. If you throw a timing light on it, it should match the number on the screen. This happened a couple of times with my homade jobbie for adjusting the timing.

 

Mabey try and look for a new shop to test fuel pump & injectors volume flow at pressure.

 

You should be pounding out the same numbers as Shane on his stock block.

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Guest Tim78zt

Clint, I'll look at the timing on the laptop this weekend. But what kind of tool can test flow at operating pressure thru the pump AND injectors?

 

I once read somewhere that hp is made in the internals (block, crank, pistons, rods, etc.). I believe that a stock turbo shortblock like Shane's is put together better than my rebuild was and this is the reason I'm lacking for more power. I'll bet you a beer if I took my (o-ringed) block out (flat-top ceramic-coated pistons and all!!) and only subbed in a Nissan-built stock shortblock I'd see 50 more horses!!

 

Tim

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Tim the motor looks good on paper, and should yield even better numbers while being even more reliable. The increase in compression should yield around 8:1 with flatops.

 

I don't get it something is wrong with either the rebuild. Or you have fuel/igntion issues.

 

I believe the fuel pump can be tested by disconnecting the fuel return. Appling say 15-20psi to the fuel regulator. Then you let the pump run into a bucket for 1 minute. Measure the fuel volume in bucket convert to cc's. Now you have fuel pump flow in cc's/min. Divide by 6 to give you how much it can supply to each injector. Hopefulley it is at least above 500cc/min. The injectors will have to be removed cleaned and tested.

 

You have a long way to come collect a beer cheers.gif Your engine definately needs a tear down and freshen up.

 

It is a good idea to try and find the problem now, it will save $$ in the long run.

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to mr mudge-the bay area will be enhanced testing soon like la and central valley.but hc are lower under load.if you egr is inop then your nox will be high.if a z is tuned correctly even with aftermarkit efi (sds,haltech.etc) it should pas a tail pipe test.some states let cars go if the pass the tail pipe test.but good old california makes you have to use all oem parts.

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