Jump to content
HybridZ

bherd

Members
  • Posts

    18
  • Joined

  • Last visited

About bherd

  • Birthday 03/10/1959

Profile Information

  • Gender
    Not Telling
  • Location
    Southern New Jersey

bherd's Achievements

Newbie

Newbie (1/14)

10

Reputation

  1. Hi all, Figured I would share what it took to get my 83 280zxt started on a Megasquirt II Extra. Coming back from a couple year restore where the engine had been torn down, bored, stroked, new turbo, I.E. everything was different. I installed a weatherpack connector between the stock ECU and the injectors (6 wires to 2), I then installed a similar connector on the MS II built from a DIYAutotune kit. I plan on doing Fuel pump speed control, boost control and detonation detection eventually as well as logging fuel pressure but may leave teh spark on stock for a while until I am more confident about detonation detection. In spite of the fact that the Megastim stimulator showed both injector banks firing, I was suspecting that something was wrong with with one bank and pulled the MSII and tested on the bench with a spare injector, sure enough one bank would fire, one wouldn't. I traced it to a cold/missing solder joint on the current sensor resistor in the current limit circuitry, so it would turn on an LED but not an injector. Still didn't fire but I would only crank it about 6 seconds at a time, after which I would then switch the plug back to stock ecu and let it "clear it's throat". I pretty much spent the winter with a fouled/flooded engine due to sporadic work in the cold, and I wasn't about to revisit that place. I scoped the injector times which on stock and found them running at 1.6ms but about 3 times as often as my 4.6ms pulses from the MS. At the end of the day I relied on the Required Fuel Calculation and didnt muck with the ECU firing configuration further. I assumed it was not starting due to being too rich but had no proof since it would either start or not (it didn't). I then started the Z with the stock ECU and jumpers between the connectors, once running I moved one bank of injectors to the MS, it coughed but kept running and I started tuning for minimum MAP. Sure enough it had been rich and within a minute or two I moved the second second bank and was even able to start the Z on the MSII. It all came down to the cell for 0kPa and 500 rpm (duh!) had been mid-thirties,and liked mid-twenties a lot better. A few minutes later I turned on auto learn for TunerStudio and witnessed a noisy AFR reading overwrite my hand tweaked idling cells... I assume you have to do this once to learn to lock the cells. So figured I would pass on the crawl then walk approach to getting an MS running, in my case at least I could run one bank from stock and one from MS until I could get tuned well enough to switch completely over without spending 20 minutes wondering how bad I flooded the engine. Bil
  2. I _think_ the main thing of water cooled is that you don't have to worry about the turbo cooking and coking up during a cooldown as much, I thought it was to cool it when running when I started but think that research showed it was for when there wasn't enough oil flow to cool. There are experts on the board that I would defere to. The guys I menetion can easily answer these questions. Bil I expect the rebuild to outlast the life of the rest of the car.
  3. I am no expert and in fact suffer from poor memory, two years ago when I was working on my turbo I was familiar with the relevant facts and knew the stock for example. It isn't a T3 I don't believe, something like a T26. I do remember that I ended up getting all of my questions answered by gpopshop guys at 479-751-7966 or google them. They sell rebuild kits and do rebuilds and seemed to have no qualms about spending time on the phone explaining everything up front. In my case I went with a center housing I could upgrade later without having to commit now to ball bearings but I did opt for the 360 degree thrust bearing. Turns out parts of my previous post were wrong, nothing was chipped those were balancing grinds I had seen, the problem with that particular turbo was that it wasn’t a good combination to begin with and had prematurely worn the bearing, which is why the guy was selling it in the first place. As far as upgrading, you may need to think some things through. More air in the form of a larger turbo means the need for more air flow capacity, in my case I had the motor out anyways and had the heads ported and added a 60mm throttlebody. More air means more fuel needed, as in modifying the system to widen the pulse for the injectors or a new ECU or both. I had looked at a Perfect Power piggyback but went with a Megasquirt because I like building things and wanted the control, I have 36 pound injectors ready to put in. With ore air you also want to watch out for detonation, I added an intercooler and am working on the det sensor integration with the Megasquirt. Good luck, Bil
  4. I have already set up fuel pressure to be one of the recorded parameters as I dont trust my abilities to catch a problem like not enough pressure (also have an FMU) by sight sound or smell. My other I/O's are set up for knock detection and boost control.
  5. Hi Moby, Thanks for all of the helful info posted everywhere, it was invaluable getting to where I am at so far. No, primary reason is that the pump is LOUD. Secondary would be pump life and even heating of the fuel going round and round. I actually have the stock ecu and injectors right at the moment (bigger ones on the shelf to match the T3/T4 I have installed) and am running the MS in parallel (I built a little isolater circuit for the CAS so that they both can run without clamping the signal) so modulating the fuel pump is a natural thing to have it do. The IGN, and INJ wires are taped off waiting to do a cutover one day to MS, but still working through getting the car on the road after a long revbuild Thanks Moby, Bil
  6. I have a high volume fuel pump on an 83 ZXT. I have built up a PWM fuel pump speed controller to give the pump a second speed, so there are two outputs from the MS of pump ON/OFF and half/full speed. The initial FP rules are still intact, the pump runs for a few seconds after crank and stops with no CAS and I have selected the logic for adding the high/low speed relay which seems to work, was simple so far and kinda cool to do. Initially my thought was above a certain RPM then full speed fuel but that doesn't account for WOT or coasting. So I would love to hear suggestions for pump speed logic or as it relates to the VE table for fuel demand and not just RPM or other paramters that are important (such as WOT?) Hope this makes sense. bherd
  7. Well I sent the turbo to the good folk at G-POP Shop. They confirmed that it was pretty trashed and for a reason, the turbo wasn’t a good fit to begin with with regard to the size and ratio of the wheels and the application. Basic comment was that the bearing wear was premature due to being too large for the application (or something to that effect). They helped me size one using my old core as core. They got my water cooling that I wanted and I can swap in ball bearings later. So the moral of the story for me was that in spite of all of the research I did prior to getting a turbo (I became a car guy only during the multiyear rebuild, I didn’t know what everything under the hood was when I first popped it) that getting hooked up with a good resource can really address answers to questions I didn’t yet know to ask, especially with regard to something that needed to be “balanced” with my application. BH
  8. Thanks. Turns out the O-Ring is definitely missing. BH
  9. Any place I can get a blow up dwg and torque/rebuild specs for the T3/T4? Someone asked if maybe I was missing a gasket on my turbo which is causing the housing to rub, to which my reply would be that if the guy who had the turbo before me (used but looks low mileage) lost it I would never know. Can a turbo be checked with an oil supply and compressed air on the bench or do I have to bolt it back on to find out if a problem is better or worse? thanks, Bil
  10. I will have to look at it from a front to back clearance point of view. I guess I didn't mention, this is a Garrett T3/T4 .49/.63 if I remember correctly. Spent about $5-600 on it originally, just didn't get to using it until recently. Any place I can get a blow up dwg and torque/rebuild specs for the T3/T4? If the guy who sold it to me lost the gasket, I would never know. Can these things be checked with an oil supply and compressed air or do I have to bolt it on to find out if it is (mostly) sound? Thanks for all of the help. Bil
  11. Think I will dissemble the turbo an take a look, nothing to lose at this point. I have the original T3 that could go back on in the meantime. If someone knows of a good set of assy instructions (with pictures) otherwise I will be following http://forums.hybridz.org/showthread.php?p=811606 If the spindle is bent, where is the best place to get a replacement? I was thinking to give GPOP a call. BTW, almost no back/forth play, I believe this is a low mileage turbo, barring the spindle wobble. Bil
  12. As I look at it it would seem that there is more of a controlled radius to the pieces then I though originally. The fact that they almost line up with the material removed from the nut would tend to mean that these are balancing cuts also I assume. That takes me back to why I pulled this out. no boost and above 3k the turbo made a "raucous noise" and impeller was clearly rubbing if not slightly gouging the housing. There is a slight wobble to the shaft, .007, that I assumed meant that at any high speed it would be acting badly, the housing wasn't just worn on one side, it was all the way around. Is there a way to test for basic soundness before bolting back on the car? This turbo is fairly clean, I don't think it has a lot of miles on it and no signs of oil anywhere, I didn't think of it as a candidate for a rebuild as it acts broken, not worn out. Thanx again. (Nice silver z) Bil
  13. Thanks for the reply. I circled the two areas where there are pieces of the wheel missing. The housing is pretty gouged where the wheel was off center at speed and the spindle doesn't have any fore/aft play but it wobbles from being bent. If the wheel is supposed to have those pieces missing (where you can see thru to the bottom part of teh housing) that will save me from trying to track down if the metal got sucked into the plumbing/engine. Bil
  14. Thanks, I was wondering how bad the $200 turbo's could be but will find a better quality replacement. Bil
  15. I just put the first few miles on my 83ZXT after a long rebuild. I had bought a T3/T4 from a guy back when I started, who sold it with some other parts as kind of a kit. It was used and now I suspect it might have been no good to him due to it's condition. I rebuilt the engine (3.0L) along the way, the engine came to life okay and everything was normal (even flew right through inspection) until I went to run it on the road under load. No boost and above 3k the turbo made the bad kind of noise. I tore down to it and noticed the turbine had rubbed all the way around in the inlet area, when I took the turbine housing off two vanes where chipped (12:00 and 8:00 in the picture) and the shaft has .007 wobble. So is this re-buildable or should I start saving for a new one? Obviously I would need new turbine, etc. This Turbo has a water cooled center section, Can I transfer the center section to a new turbo where everything else is the same overall? I am seeing a lot of "new" T3/T4 imports on eBay for $200, anybody have any experience with the imports as opposed to the Turbonetics or Garretts? Thanks, Bil
×
×
  • Create New...