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1993 Quad4 GTZ: Project WTF

Posted: Sun Nov 03, 2013 8:31 am
by DanteGTZ
Where to start... I bought my current 1993 GTZ in Wisconsin. The engine was removed and mostly disassembled but the seller claimed it was all there. I got the car back to Tennessee and began to work on it. I found many things that were not consistent with a 1993 GTZ. The axles didn't have ABS teeth, the intermediate shaft was for a pre-92 car, the fuel rail was for a pre-92 car, the intake was wrong for a 1993 (and much more). Apparently, I was sold a 1993 GTZ with a bunch of parts from some other Quad4. The car also came with a 'rebuilt' cylinder head.

After spending a large sum of money on rebuilding the engine (new timing set, oil pump, machine work), I put everything together and back in the car. I was happy to hear the engine fire up almost immediately. My excitement was cut short when I noticed that there was no oil pressure registering on the gauge. Apparently, there is an oil gallery bolt that needed to be put back in the block to prevent the oil from pumping directly back into the oil pan... After pulling the pan off and reinstalling the bolt, I now had oil pressure - and a bit less bearing material...

After sorting the oil pressure issue out, I noticed the car would still not idle. I checked everything - The IAC, TPS, vacuum connections, everything. I even picked up another intake manifold, TB and a whole bunch of other parts and through them on just to make sure everything was in working order - The idle issue never changed. The car would run, but it would jump between 2500-3000rpm at idle.

In addition to my idling problem, the car lacked the expected Quad4 power. It didn't want to rev past 4500rpm and just didn't have much get-up-and-go. Because the car came with an unusable (in this application) fuel rail, I had to find a replacement before I could get it started initially. I wound up finding a rail from a SOHC Quad and bolted it on. FYI - They will bolt on, but don't fit quite right. I assumed that my power issue was because I was using SOHC injectors. I eventually picked up some HO injectors and installed them. To my surprise, the power problem was still there. I drove the car around a bit just to put some miles on it, but honestly, wasn't having much fun. One day, less than a mile from my house, the car began pouring white smoke from the tail pipes. I know what you're thinking - Quad4 Head Gasket - but (a) this was an enormous amount of white smoke too much to be a simple HG, (b) the engine has head studs and less than 400 miles on it.

Things started making sense... The rebuilt cylinder head looked clean and freshly rebuilt, but looked to have had massive repair work done to it. I'm guessing that there is an internal crack on the head that is causing not only my idling issue, but this smoking issue as well.

At this point, this GTZ has earned it's title: Project WTF

Last night, I decided to pull the engine - I'll tear it apart to see if I can find out exactly what the problem is/was and see if I can't get it figured out.... on a plus side, last night was the first time I've gotten to use my new shop space for a large project - I can't even describe how nice it is to have adequate space to work and a place to properly store and organize tools!

I had apparently started a small thread here: http://www.beretta.net/forum/viewtopic.php?t=13704
I will update this thread, not the other.
pickup.jpg
...more to come...

Re: 1993 Quad4 GTZ: Project WTF

Posted: Sun Nov 03, 2013 10:46 am
by spacecadetz26
good luck :)

Re: 1993 Quad4 GTZ: Project WTF

Posted: Sun Nov 03, 2013 7:22 pm
by Asylum
Seems you obviously got sold a "Bill of Goods" but you actually got it together and it ran.

It's actually interesting to hear about all the changes a Quad went through over subsequent years that make them non-interchangeable parts wise.

And I would be hiring a Hit Man for the seller!! :runsies:

Keep you chin up!

:beer:

Re: 1993 Quad4 GTZ: Project WTF

Posted: Sun Nov 10, 2013 4:15 pm
by DanteGTZ
Just this past week I wound up buying a brand new NOS 1994 Quad4 DOHC, low output and am having it shipped back to TN. I have all of the parts to build an HO so that is what I'll do before I install it. It's gonna be a bit of a process, but it should go pretty smoothly.

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 6:11 am
by DanteGTZ
The new engine arrived earlier this week - Last night I finally took some time and tore it down to see what I was working with. Before anyone asks why I torn down a brand new engine: This engine had been sitting for 19 years. I wasn't going to assume it was still in perfect shape - I had to KNOW. Plus, I'll be putting my 086 head, W41 cams and a new gasket set in it... There was no way in hell I was going to run the factory GM head gasket. Oh yeah, and she'll be head studded as well.

Anyway, the engine looks pristine - It is 100% NOS, not a rebuild. It's perfect! Aside from needing to breath better with a different head (the 303 casting has TINY exhaust ports), she's a keeper!

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It appears that what I thought was originally a Low Output motor is an HO motor - At least judging from the pistons inside. I thought originally I was going to have to swap my old HO pistons in it but I was thankfully saved from that task. It was a bit bittersweet tearing into this motor that had sat on the same pallet/stand for almost 20 years, but ya gotta do what ya gotta do. This way I'll know exactly what's inside my engine and can feel confident knowing everything is 100% new as the seller had claimed. I'm hoping to get it built this weekend and maybe hung in the engine bay... We'll see...

On a side note, these Quad4s are getting easier to tear down with practice. There really isn't a whole lot to them as far as assembly goes. Quite surprising, considering the engineering. ;)

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 7:17 am
by Money pit Beretta
How in the hell did you find that?

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 8:25 am
by 1988GTU
I am curious how much $ it set you back.

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 9:07 am
by DanteGTZ
found it on ebay of all places. I was the only bidder at 600 bucks. there was a ditional freight cost but that's just a given

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 10:21 am
by 1988GTU
600 is a really good price. Cant do a full rebuild for that cost.

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 11:10 am
by bonecrrusher
Needs Bilmar powah!

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 12:36 pm
by DanteGTZ
yeah but unfortunately that ship has sailed never to return

Re: 1993 Quad4 GTZ: Project WTF

Posted: Thu Nov 21, 2013 3:07 pm
by Money pit Beretta
Damn lucky on that one. I'd be happy to pay that kind of money for a GM reman.

Re: 1993 Quad4 GTZ: Project WTF

Posted: Sat Jan 11, 2014 3:23 pm
by MY91GT(Z)
Hows evrything starting to looking now??

Re: 1993 Quad4 GTZ: Project WTF

Posted: Mon Jan 13, 2014 6:04 pm
by 3400beretta
I am in no way a quad 4 expert, but from what I remember, isn't the HO supposed to have 4 reliefs in each piston?

Re: 1993 Quad4 GTZ: Project WTF

Posted: Mon Jan 13, 2014 6:10 pm
by 3400beretta
Also, make sure that you check your 086 head over really good for cracks.. at this point if I were you I'd take it in and have a machine shop look it over.

And I would check to make sure the correct prom is installed in the ECM. Since you've found so many other incorrect items on the car - this could have been the source of your idle problems and lack of power.