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Discussion Starter #81
Ah okay. I decided to just buy a set of stock 360cc injectors from Aaron (92VR4widebody) since they are so cheap. He said he has several sets so you might want to PM him or post in this thread if you wanna go that route:

http://www.3si.org/forum/f4/im-baaaaaaaaaaaaaack-813754/index4.html#post1056262514

I got them for two main reasons (might be somewhat related to your problems):

1. I am getting excessive knock trying to run shitty CA 91 pump with RC 550cc injectors using SAFC2, and I suspect the injectors might be the problem. These injectors have 120k on them and the correction % i am running in SAFC II does not make sense for the size of the injectors (less negative than it should be), so I am worried one or more injector is not flowing as it should be causing lean condition in certain cylinder(s). FWIW about 8 years (and 80k miles) ago my car was tuned by GTPRO with these exact same injectors (and no engine mods since then) and it ran completely fine. SAFC numbers have been adjusted since then which i think is because the injectors need a full clean/flow/service. It was tuned at like 12:1 AFR and even when i try running 10.5:1 now I still get crazy knock. My motor mounts have been replaced so i dont think its that. When chasing knock problems most people recommend filling up with a few gallons of race gas (100+ oct) and seeing if the knock goes away. That can help narrow down to a fuel problem. I havent been able to try this yet.

2. After i recently fixed my rear O2 sensor and started getting closed loop operation again, i noticed that my low throttle acceleration is very uneven when the ECU is trying to correct fuel to maintain 14.7:1 AFR. I can literally feel the injectors cycling if that makes sense - the acceleration is not smooth (not quite jerky but kindof close in 1st). There is no sputtering/backfire/etc it just seems like the fuel delivery is poor and uneven. As soon as it goes into open loop (even still light throttle just generally above 3000 RPM), acceleration instantly smoothes out and AFRs are low 13 (again low throttle not in boost). It is most noticable in lower gears of course. Hard to tell at cruise on the freeway in 5th.

The more i think about it, I think it would be a good idea for you to disable closed loop and see if that fixes your low RPM uneven acceleration issues (if the PTU didnt?). IIRC you are using chrome and i believe there is an option to do just that, so it should be a quick and easy test.
As usual, more good considerations there.

I'm not thrilled about the idea of dropping in used parts as that always leaves some uncertainty about their condition if the problem does not go away. But on the flip side, if I drop in stock injectors then I don't have to worry about trying to dial in different latencies -which is something I haven't gotten into yet. I haven't even wired up the flash port for the Chrome ECU, it's strictly working as a factory replacement now. My thought process all along was to try and get the car running back to stock before I messed with any flashing, again just because that is uncharted territory and I'm trying to eliminate the number of variables I'm introducing as I step through my troubleshooting.

Disabling closed loop though might be worth it for sure -especially if it's something I can turn on and off without changing anything else during the flash.

I pulled the crank pulley and verified the timing using the sprocket's mark on the block. Good news is, I'm still timed properly. I put that all back together and got a look from the underside with a mirror directly in front. From that view the mark looks much better, so now I know where to look from if I need to check this again against the timing cover.


I also struck some lines across the different sections of the damper, which should provide an easy way to tell if that starts slipping on me again (assuming they don't wear off over time).


I'll regroup after I get the new mounts in and get a fresh set of logs, with a minimal amount of parameters (as futurevr4man suggested). Only working on the car an hour or two at a time has really slowed the process down.

These mounts look like they're going to be a bitch. I haven't even put my eyes on the rear mount yet. Does the subframe brace that runs fore and aft have to come out to get the two lower ones replaced? If it does, would now be the time to use that access to drop the downpipe and gut my pre-cats? Or is that job doable enough on its own with that brace in place (going off of memory now of what it looks like under there).
 

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The rear mount is a pain to access, but it isn't too bad. Here's the guide I used 1995 3000GT VR-4: 3SX Polyurethane Motor Mounts Installation
The precat gutting isn't too bad. I'd recommend going to an exhaust repair shop and see how much they'd charge to make you front precat replacement pipe. I had one made for $50 and it fits perfect. Make sure you wear a mask, good goggles and a bandana or something to cover your head if you do the rear precat while it's on your car. I wore racquetball goggles (yep I'm dumb) and got a piece stuck in my eye. Luckily it didn't damage anything after the Dr pulled it out.
 

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Discussion Starter #83
The rear mount is a pain to access, but it isn't too bad. Here's the guide I used 1995 3000GT VR-4: 3SX Polyurethane Motor Mounts Installation
The precat gutting isn't too bad. I'd recommend going to an exhaust repair shop and see how much they'd charge to make you front precat replacement pipe. I had one made for $50 and it fits perfect. Make sure you wear a mask, good goggles and a bandana or something to cover your head if you do the rear precat while it's on your car. I wore racquetball goggles (yep I'm dumb) and got a piece stuck in my eye. Luckily it didn't damage anything after the Dr pulled it out.
Thanks for sharing that link! I knew I saw that instructions before. I thought it was on 3SX's site, but couldn't find it. I forgot about checking supercar-engineering.
 

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Yeah, you can do the mounts with the engine in the car, you'll be fine. Front and rear mounts are the only real critical mounts, the DS and trans mounts will help, but they don't take the brunt of the torque like the other two.
 

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Discussion Starter #85
I'm still making very slow progress on the mounts. I managed to get the downpipe off while only snapping the bolts on the aft-most flange the connects it to the main cat. I'm not happy to have to drill those out, but it could have been a lot worse with 23-year-old exhaust hardware, so I won't complain. I hope to get the rear mount knocked out tonight.

While I was under the car working on the exhaust, I noticed that my carrier bearings are shot. Here's a .gif of the front one, the back is just as bad:


I found OEM replacements the cheapest on 3swarehouse.com, so I was going to order a pair of them and get them done while I have the car up on all fours. To those of you who've done the job, are there any other parts I should absolutely look to do while I have the propeller shaft out? I don't feel any slop in the u-joints themselves while moving them by hand. Is the transfer case seal an easy/cheap one to do while I have it out?

The procedure looks pretty straight forward in the book. Anything else I need except for the two bearing assemblies?
 

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For what its worth.

I replaced some on a friends VR-4 a few years ago. New OEM Mitsubishi...

It was NOT a easy or fun task, a huge pain in the ass honestly...

they still felt almost just as sloppy once we put it back in, and they move around quite alot...

if we could do it all over again, we would have just replaced them with a single piece aluminum driveshaft.
 

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For what its worth.

I replaced some on a friends VR-4 a few years ago. New OEM Mitsubishi...

It was NOT a easy or fun task, a huge pain in the ass honestly...

they still felt almost just as sloppy once we put it back in, and they move around quite alot...

if we could do it all over again, we would have just replaced them with a single piece aluminum driveshaft.
Really? I didn't think they were bad.

I can't think of anything else to do OP. I wouldn't mess with the Tcase seal if it's in good shape. You can remove the T-Case by itself without having to remove anything else in the future anyhow. It's easy.
 

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Discussion Starter #88
I have two OEM carrier bearings on order, so those will be going in before the car comes off the stands.

Making room to access the rear mount from the top side, I noticed my c-shaped fuel line from the tank has a kink in it:


Let me know if anyone has a used one they'd like to part with at a good price.
 

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This is a great thread - your intro post has everything: action, suspense, heartache, hope!

Good luck keeping her on the road - it's getting more and more challenging as they age. The problems seem to be getting harder to diagnose and more difficult to fix.
 

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I have two OEM carrier bearings on order, so those will be going in before the car comes off the stands.

Making room to access the rear mount from the top side, I noticed my c-shaped fuel line from the tank has a kink in it:


Let me know if anyone has a used one they'd like to part with at a good price.
$62 on 3SX if you want a nice shiny one - which is the route I went when I replaced my entire fuel system earlier this year... Was too hard to find one that wasn't rusty or kinked. I imagine with a little bit more digging you might find one that is slightly cheaper than 3SX

https://www.3sx.com/stock-fuel-filter-attached-parts
 

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Discussion Starter #91 (Edited)
I didn’t mean for over two months to pass without an update, but I’ve only had a couple of shifts to put into the GT since then. There’s a good reason for it though, on July 13th my wife gave birth to our daughter, Harley Nicole Hein:

We’re really blessed. Momma and her are doing great, and she's growing like weed!
(Harley at five weeks)



Hopefully I’ll be able to get the GT off the stands and keep it off long enough for her to drive it someday.
(GT on stands)
 

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Discussion Starter #92 (Edited)
I’m still working on the mounts… and the propeller shaft…
My father-in-law and I pulled the propeller shaft and began to R&R the carrier bearings.


I was able to do all of the pulling with the Harbor Freight three-jaw set, and most of the assembly using a heat gun and a freezer. I was a little slow getting the last flange seated, so I had to take it down to a neighbors and finish it off with a press, but with a little more quickness the job would be very doable without the press.



My lobro joint boot was still intact. But after getting the carriers replaced and the shaft sections painted I decided that it’d be a huge pain if I put all this work in it, and ended up having to pull it out again in another year or so just to do that boot. This got me into a shitty situation with 3SWarehouse.com (Ground Zero Performance). Before cutting my boot I looked for one online. 3SWarehouse were taking orders for backordered boot kits. I bought it and proceeded to tear mine apart so I could separate the joint. Weeks later, I tried calling and emailing the shop to see if they had any idea at all when the unit would arrive. But they wouldn’t answer any emails, and their voicemail box is always full so you can’t leave a message. It sucks, but I had no choice but to have my credit card reverse the charge so I could look elsewhere. Come to find out if you search on the forums, you’ll find a lot of people here that have had the same experience with GZP. It’s too bad. I’ve had other uneventful purchases from them in the past. I had time to wait, but without any way to get in touch with them I had to pull back my funds. I contacted Cherry Hill, and they had one boot kit left on their shelf, which I had in my hands a few days later (very quick shipping and processing). I still have the propeller shaft sections apart, waiting until I wrap up the engine mount R&R.
 

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Discussion Starter #93 (Edited)
The rear mount has been a real bitch. But after a lot of frustration trying to get the two driver’s side bolts holding the mount to the sub frame, I decided that I would just keep pulling pieces out to get all the access I needed. I’ve seen that you can get the job done without removing the transfer case, but while under the car I’ve noticed that the T-case and the sub frame area are all being coated by something leaking (oil I presume) from above. I decided to pull out everything that I could so that I could give it all a good cleaning and hopefully chase the leak down, while getting all the access I’d need to conveniently pull the rear mount.
Out came the transfer case and driver’s side half shaft assembly:



Out came the rear O2 housing and pre-cat, which also gave access to remove the mount bracket from the block.
This’ll also give me more convenient access to gut both pre-cats off the car before going back in.



Finally the rear mount could easily be unbolted and removed:

I’d say it was pretty worn out.


Before all the reassembly, I’ll give everything a good cleaning so I can keep an eye out for the source of the leak (I think it’s a passenger side camshaft seal from the rear head).
 

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Discussion Starter #94
Which is where I'm at now. I have a lot of cleaning to do under there. I have to gut the precats. I have a new c-shaped fuel line and filter to go in, as well as the passenger side and front engine mounts. Hopefully another few shifts and I'll have it back on the ground to give it a wash and log a few runs.
 

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Discussion Starter #96
I pulled the passenger’s side fore/aft running support so that I could continue cleaning around the gearbox. Takes forever to clean, but I love getting back to shiny parts.



I decided that I might as well pull the oil pan so that I can knock out the small dent, give it a repaint, and scope out the oil pickup screen to make sure everything looks okay. I haven’t noticed any oil pressure issues, but I’m just about there anyway at this point, so I might as well knock it out and get full clearance back. I pulled the starter and the fwd engine/trans support bracketry –which will all get a good cleaning too. It looks like the oil pan is ready to drop. I think once it’s all unbolted that I should be able to tip it down and sneak it out without pulling the driver’s side fore/aft support. Does anyone know if that’s possible? Or is removing the driver’s side support an absolute must for getting the pan out?

 

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Discussion Starter #98


Any pro tips for separating the oil pan? A special kind of scraper or wedge maybe that works with this limited access to cut through the old RTV? Or do I just give it hell prying it off and worry about straightening out the flange afterwards?
 

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I use a thick putty knife/scraper. It's thick enough to pry with, but thin enough to get between the pan and block. You can straighten out the oil pan flange after it's off.

It's not graceful, but it works. The grey RTV fills in the gaps. Note that you use the grey, not the red.
 
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