Sorry 100psi-120psi isn't "fine" for a 2jz-gte. As I already mentioned to you in another thread, 20psi is beyond the maximum allowable difference between min & max cylinders.

Also ime these compression numbers are VERY VERY low, relatively speaking. Although readings do vary a bit between compression test gauges and depending on the exact procedure used for the compression test, (fwiw) I've never seen (only) 100psi in any 2jz-gte that is "fine". In other words, I agree with Suprra_girl & MrNickleye that the internals of this 2jz-gte need further inspection, and likely some (or a lot of) work+parts.

Hey great link. Yeah from the TSRM itself compression should read at 1079kpa/156psi and at least 128psi the difference between each cylinder should be around 14psi. So in essence there is a serious problem with the motor. Going on what t88widebody has told us and the diagnostic readings we have so far I would recommend a complete tear down and place some forged goodies in your motor.

Now of course the 2jz blocks are strong to begin with but like every motor it has its limit. 1400cc injectors with a T88 turbo is obviously pushing it. Also we dont know what type of engine management you are using but if its not adequate then that could mean problems as well. Now imho I would tear it down and do a complete engine rebuild with forged goodies to prevent that from happeneing again. Oh and if you are running that much boost and fuel I would highly recommend getting a standalone or at least the emanage.

That's what suprra_girl and I have been trying to tell you.
You have no basis for that recommendation. Until you know 94T88Widebody's horsepower goals, and until we know for sure exactly why his engine has apparently lost compression, you have no basis for saying he needs "forged goodies".
Afaik, there is no such thing as 1400cc injectors. :frown: Please post a link to where YOU last purchased a set of them.
Also note we don't know which model of GReddy T88 that he's running, nor do we know his target/max boost level, nor the type of fuel he plans to run. Why are you making assumptions and jumping to conclusions about what do do with his engine, before we're even sure if we have his ignition problem solved?
No, we actually do know that. :rolleyes: It's called an AEM
...what did you think he was talking about - a cold-air intake? :rolleyes:
If detonation caused the damage, "forged goodies" won't prevent detonation, nor will they survive further detonation.
Again, he does have a standalone. :frown: It's called an AEM.

Again, please don't post on technical threads in this forum anymore, unless it happens to be a thread that you're certain you know what you're talking about. For example, if you've EVER personally worked on a Supra as highly modified as 94T88Widebody's please post your reference(s) immediately (yes, I will contact them). If not, please don't further pollute threads like this with any more of your wild guesses. Your lack of understanding, misinformation and potentially bad advice is getting in the way of us trying to help 94T88Widebody get his ignition & engine problems solved...

no need for argument here! I am well on the way to getting that damn gear off the main.. What a pain... it is about 90% off and I needed a quick break.

I understand that I have low compression. I fully plan to build a block that can keep up with my externals. I know now even with the low compressoin the car is running 788 to the wheels on C16 with 32psi of boost. I am still pumping ryan for the Dyno sheet.. I think he has forgoten

I than EVERYBODY for thier opinions... I do appologize for not having the images you guys want to see just yet...you can see some images as the parts were being added and you can see an exterior shot in my myspace profile

www.myspace.com/dingholla

Even at 32psi, your Supra's engine should not have detonated if you were running pure c16 (if properly tuned). On the other hand, if you were running anywhere near that boost level on 91 octane, we can be certain detonation is at least partly to blame for your melted plug and low compression. Also note that consistent 120's (or less) across the board is (ime) a quite unusual pattern for detonation damage: as a result, I believe there's still an outside chance that that running with a broken timing belt tensioner bracket might have 'tweaked' your valves...which in turn could be affecting your compression #s. Please verify if at all possible that you're still running stock cams (very unusual with a setup like yours), which headgasket you're running, and whether or not your head has been decked.

I'd suggest that, as soon as we verify your spark is functioning properly again (after the CPS gear has been repaired), we begin troubleshooting on your engine's compression (and melted plug in #4) ... as well as the various options to best resolve those problems. For example, we need to delve into: precisely state your horsepower goals, identify the exact type of fuel you plan to run (c16 full-time?), and detail your application (eg. drag racing?). Until we've identified all of these items, and gone through a proper troubleshooting process, it may be premature to conclude that your block must be 'built'.

Among the troubleshooting steps I'd suggest include another compression test (with a different gauge and some tips I'll give you to ensure optimal accuracy), followed by a leakdown test...but again let's ensure your ignition is 100% fixed after you reassemble, and then we can get into the other issue.

just a quick note.. the car is running great.. I will be back for the follow ups soon... I was not running C16...

I was running 91 octane and 18lbs of boost...

the block is STOCK

engine bay pics you wanted
 

Engine Bay photos!


http://drewman.team24seven.us/Drew1.JPG
http://drewman.team24seven.us/Drew2.JPG
http://drewman.team24seven.us/Drew3.JPG

Thanks for posting - your engine bay is beautiful.

If you don't mind me saying so though, that's an awefully big turbo, intake & throttle body to be running with stock cams...

Are you sure your turbo is a GReddy T88? From those pictures, it doesn't look like a GReddy T88 to me...

Its a GT47-88.... I never said it was a Greddy

Actually you did, when you said this (qft):
Fact: The only company that makes a turbo generally referred to as a "T88" is GReddy. Although Turbonetics also makes a turbo called a Y2K T-88, that particular turbo isn't generally referred to without including the prefix/acronym "Y2K".

As I said earlier (and no matter who manufactured your turbo), your engine bay is sweet! :) This was the point of my post, not to start an argument about turbo nomenclature. In addition, there's a very significant horsepower difference in a GReddy T88 and (what we now know is) your GT47-88 ... my comment about your turbo not looking like a GReddy was trying to clarify the exact specs of your setup, for future troubleshooting purposes.

Also note that (from the pictures you posted) I don't see either an HKS DLI or an AEM CDI mounted in the engine bay. If you're not running an ignition amplifier with your AEM, you will experience ignition misfiring under high boost. Although this might partially explain the misfire you talked about, the 18+psi you were running on 91 octane pump gas was likely a primary contributor to both your melted sparkplug and your "100 - 120 psi" compression.

Again, to best recommend next steps to help you avoid melted sparkplugs, low compression (engine damage), etc. in the future, please shed some light on your horsepower goals, identify the exact type of fuel you plan to run (c16 full-time?), and detail your application (eg. drag racing?). ...and do you plan to spool up that big GT47-88 with any NO2?

P.S. Did you buy your Supra from Chris Msungi? I showed your engine bay pictures to a friend of mine, and he says he recognizes your widebody Supra (less the HKS Twins) from when Chris brought it to Tx2K3...