2seater

The factory did both low and high boost prototypes in the late '80's, since destroyed, but it can be done in the engine bay. I did my own installation , essentially scratch built piping, and it does fit under the hood, but there isn't a lot of room. The Squire's type installation of rear mount turbo has pros and cons. The obvious pro is the space available for the turbo itself but the cons are several: the lubrication system must be either self contained and recirculating, plus cooling, or a scavenge pump must return drain oil to the engine oil pan. The drain side of the turbo center section cannot have any residual pressure or the seal(s) will leak. The environment under the rear of the car does not lend itself to cool, clean inlet air to the compressor plus you must run what is essentially another complete exhaust pipe from the turbo back to the throttle body. I am sure it can be done, STS makes kits for various automotive applications, but it isn't as simple as it might seem.

I admire your gumption and understand what you are after. It has been several years since I looked for a replacement engine to "improve", but at that time, engines and transaxles were plentiful, and cheap, even low mileage ones. Unfortunately a 20 year old drivetrain may have gone off to scrap, but it might be worthwhile to check? Even though common, the rebuild parts for a Buick are generally much higher than for the common Chevy equivalent. There is certainly a sense of satisfaction when your own handiwork hums to life and I tend to take the road less travelled myself. The only concern I would mention is: if one of the more robust parts of the car has this many problems, what other areas may show up down the road? I wish you well with your project.

Yes, I did, although I don't remember if it was 3.84" or 3.86" I believe it was 3.84", the maximum overbore recommended, but for some reason, I did not write it down. At some point I want to pull the engine down that I installed them in to check for damage from my first turbocharging effort but that won't be for a while. You don't have your old gaskets yet?

In this case, the gasket is only sort of unused. It was not run, but it was installed and torqued in place. I had misgivings about the bore dimension, in hindsight, (I was going for max. compression ratio at the time), so I removed them and replaced with the GM gaskets. It also cost me another set of torque to yield headbolts. Personally, I like, and use, FelPro gaskets, and the bore diameter in this case was just picking "nits" due to what I was trying to accomplish at the time, (+.050" comp. height pistons).

Not a big deal, about a 1/3 cc different @ .040 thickness, unless you are after maximum compression ratio. It does increase the crevice volume slightly but will probably fill with carbon anyway? Aftermarket stock replacement pistons are way worse for dropping the compression ratio. Usually destroked, meaning lower compression height, assuming the block will be decked, and dish volume in piston may also be larger. This works good for a boosted engine.

It is possible there is more than one part number for FelPro's although looking through their catalog reveals only one. These are 9556PT. The ones illustrated came in a kit for the top end. My bad on the measurement, it is actually 4.01". The overall distance over the adjacent fire rings is .225".

The stock GM gaskets @ 3.84" were the best that I found. The FelPro's I received were over 4", 4.10" to be exact. I don't have the old stock gasket to show for comparison. Sorry for the quality of the photo. Maybe you can zoom in to see better detail. This is the FelPro.

My notes don't indicate any substantial chamfer, just a smal edge break to facilitate piston installation. Pistons are over .040" down the hole. Combustion chambers are < 40cc's. Perhaps Recian has further input having just had the heads off?

Well, a week has elapsed and the car hasn't missed a beat. Good, I guess. The only other thing I replaced, aside from the CPS, was the EEPROM in the ECM. I installed the one from the ECM I purchased from Master Finn. No real change there although it does appear to have lost about 1/2"Hg of idle vacuum. Coincidence? Maybe a slightly lower commanded idle speed? I did buy a Nano V1 o'scope. Neat little item, but to a novice, hard to understand and the manual was certainly written/translated by someone that doesn't use english as a primary language. I found this website that describes the operation, sort of "For Dummies" videos and also a free software upgrade from a Ben F. The software upgrade improves the functionality, appearance and a (19) page manual that is a vast improvement over the one included with the unit. The new software automates some of the setup functions,changes the command keys and expands the commands with sub-menus: Using the DSO Nano pocket storage oscilloscope | Hey, James! How do I … ?

Sorry Recian, I misunderstood which plugs you were meaning to replace. I ASSumed you were talking about the two inside the bellhousing area since the transaxle was mentioned. I know you are a handy guy, judging by the work you are doing, so I was interested to see if it was possible to replace those in the car. I didn't see how it was possible, but I thought maybe you had figured it out. Ooops! Regarding the exhaust manifold gaskets: many gasket kits do include them, assuming the surfaces will be eroded and/or warped, but they are not used from the factory on these engines. I have used them in the past as well, but they don't play well with a turbo installation. The heat and high exhaust pressure tends to blow them out. I file the manifold flange flat before installation without gaskets.

No exhaust gaskets used from the factory. Are you planning to pull the flex plate to gain access to the rear core plugs? I have not tried this but I can see where it may be possible to do if the area is cleared anything removeable. I would agree the rubber expanding plugs are likely the only feasible option for replacement.

I have only used the GM headgaskets after I discovered the Fel Pros' had too large a bore diameter, which would cause a loss of compression. I never investigated further to see if a steel shim gasket (thinner) was available. I suspect Cometic, Victor Reinz et al. could make you a custom set. ZZP and maybe Dr.J's may have something as was suggested earlier.

Jon, I don't know about the milling question, deck thickness and such, but are you looking for more compression? My best guess would be to check the available internal lifter travel before it bottoms out? I don't know if feasible to shim the rockers up due to the design of mine but yours may be different? The reason I asked about compression is the possibility of changing pistons. Believe it or not, the Ford 3.8 was loosely based on the Buick design. The bore/stroke relationship is slightly different but standard bore Ford pistons should fit a slightly overbored Buick and are available with a smaller dish or flat top, compression height correct and the pin diameter is even correct for my LN3. I have considered building a dedicated E85 engine with much higher compression, maybe 12:1 or so, hence the investigation. Maybe useless info., but you can always discard.

Yes, I understand. I have followed your tale of woe also. I think I will just drive it and see what happens. It's one of those things that probably doesn't mean much, since it appears to work. But, the inconsistant/confusing info I have gathered is either showing there is a difference between sensors, or, the meter is incapable of displaying useful information? Unless something more concrete shows up, it is going to take a long time for me to be comfortable with the durned thang.

I just got back to the problem child and I did find the signal from the new CPS is now different than before, but still confusing. The 18x shows 1.2 kHz at a slightly elevated idle and the 3x shows 60Hz. I didn't save a copy of the original signal for the CPS, (damn), so I can't compare to see if I read it wrong. Padgett, any chance you could try your new magic box on those two signals to see what it should look like? I am definitely move that item up on the list.

Interesting question. I suspect it will run with just the ECM, plus the ICM/coil pack which supplies the initial spark. You may be breaking new ground if you find out what it takes.

It sounds like it should work well for automotive testing. It certainly is priced right and is convenient. MAF range is 2.0-10.4kHz. It will be interesting to see your results. I did pull the CPS and physically it looks fine. I checked the resistance between pins just to see if different between new and old sensors and they are, by a lot. No science involved, just comparison of two parts. Maybe there is something there, maybe not?

Padgett, nice little unit. I will put that on my wish list. It looks like about the same money as my VOM, but with a different capability. I absolutely agree that the O'scope is preferred for this type of asymetric signal, but I used what I had. I suspect as long as a variable signal is outputted the CPS is working but the added detail would be nice to have. Mc, the meter sampling rate is selectable but it is never very fast, once or twice per second max. Your conjecture about the meter "smoothing" the readout sounds logical. It wouldn't be quite as bad if it would give an indication it is about to fail, like a bobble or hiccup, but it doesn't. It simply shut off with no warning, just like the key was turned off. The comment about only the CPS and ICM being used for start and running got me thinking about the dash, which stayed on when it quits. I think there are different circuits in the ignition switch that power different items, but that would lead me to believe it isn't related to the ignition switch itself. I do appreciate the insight and comments.

Dave, I never got back to you regarding the '89 Eprom in a '90 model but the chip sounds even newer than mine (ANWU) and my '90 was built in 1989, so maybe early models carried older designation chips? In any case, I am stumped. I cannot make the car fail no matter what I do. I have not disconnected or modified anything aside from the original battery and associated connections in that area. I thought I had it fixed at that point but it failed last weekend but always revived itself. I have wiggled, tapped and pulled on everything I can find. I have the lower instrument panel and console removed so I can access all of the boxes, connections and ignition switch. I ran the engine for 1/2 hour with a blow dryer heating the CPS, and today I heated the ECM to an internal temperature of 136 deg.F and also let it run for 1/2 hour, nothing happened. Idle remains good, fuel pressure stable @ 37 psi, steady engine vacuum @ 18" and timing of 19deg. I have tried "hot soaks" of 5-10 minutes several times but it never fails to start and run smoothly. The one thing that has changed is the check engine light and associated knock sensor code is gone. The only other unanswered question is the 3X signal from the CPS. I still get something like 9X or about 1/2 of the 18X signal? Is some of the divide-by circuitry in the ICM and the signal from the sensor itself is more "raw"? I am tempted to go ahead and replace the CPS as I have a new one and the symptoms are classic CPS failure. Replacing it by the side of the road would be impossible but plugging in a replacement ECM is no problem. To paraphrase "If it ain't broke, you can't fix it".

I just had a 4-wheel alignment done on mine after an inner tie rod end replacement. The spec they gave me from their computer readout is pretty close to what the FSM says (the range is slightly different) but I was told the same about the rear camber, "not adjustable". I purchased the appropriate shims from Rock Auto to get both rears in approx. the same slightly negative camber aspect. The shims work very well and are a simple install. Now the rear tires look even, side to side. One note of information, I had to order two different brands due to availability (Raybestos and Moog), also a bit different in price, but the parts are exactly the same, even the instructions have the same part number on them.

Edsel, I have wondered about that possibility also. I have not been able to recreate the engine stoppage by closing the drivers door or hood, which it did originally. That would have made more sense than the CPS regarding a small vibration causing a stall. I will look into that also as the key is hard to turn, on occasion, for no apparent reason. However, wiggling the key and slapping the lower steering column doesn't seem to have any effect? Padgett mentioned an O'scope, which I do not have, but it got me to thinking about the VOM I mentioned. It came with a cable and software to use it connected to a computer, where it will display, record and graph the recordings, which can be done for extended periods of time. This is a screen shot of the meter operation on an old notebook computer I have downgraded to garage use. This is the same computer that has my TunerPro software and files to connect to the car for recording and readout from the ALDL, also for extended periods of time. The graphical screenshot is not really amplitude of the 18x signal, it is the change in frequency as the engine idles. I would think, it would also give an indication of the signal while the engine is cranked for a situation where the engine will not start?

Of course it is running normally again, damn. I tried a noid light and that will kill the engine when probed while running. I thought it likely would since it's really only a light bulb. I'm not enough of an electronics whiz to make something that will allow the engine to run and keep an indicator connected. I have a lot of LEDs' and could probably make something with a dropping resistor but it sounds like the Radio Shack assembly is already done and perhaps has enough resistance to not short out the signal wire? Does anyone have any insight? The frequency function does work while running. The 18x signal made some sense, showing 325Hz, which would seem about right for a slightly raised idle due to initial start (approx. 1000rpm). The other signal, labeled as 3x, doesn't make sense, showing around 160Hz. At the same engine rpm that would be more like a 9x signal?? Is this maybe indicative of some sort of error that could be used for diagnosis? Supposedly, the engine will continue to run with one of the signals out of whack (don't remember which one) but not the other, or both. I think the check engine light is supposed to come on and you are instructed not to shut if off and get to a service facility because while it will run, it won't restart. Ronnie, don't despair. The instructions are good, unfortunately mine won't stay broken. A VOM with the frequency function isn't terribly expensive. Mine is from Radio Shack but I'll bet there are others for a good price in other places.

Mc, I couldn't agree more and I intend to do just that. I wonder if the frequency function of my VOM will work for some of what you mention? I use it to test MAF sensors and it works well for that. Mine is definitely not a fuel delivery problem. It started and ran for several minutes with a fuel pressure gauge attached. It did finally die but the fuel pressure remained steady. Actually, it jumped up when the vacuum went away. For some reason, mine will not remain broken. It started and ran normally just now. Testing while in the non-failure mode will likely yield negative results.

Thanks for sticking with me guys. I arranged to have it flatbedded home. I got there ahead of the tow vehicle so, of course, I tried it. Started right up and ran like nothing was wrong. I let it go for 1/2 hour or so and finally shut it off. Nothing I did would cause a stutter. I started it again after a few minutes and I ran though the diagnostics but of course, everything is normal. It ran for about five minutes and then just shut off. The tach drops to zero as the engine stops but no erratic behavior from any gauges. It will now crank but not start. Occasionaly I will get a couple of fires but I think (hope) it will stay broken. It certainly acts like the crank sensor so I will check it out and probably replace. I know I have given the same advice many times but I think some coincidental things have led me down a false path. At least it is home so I can investigate at some leisure. Fuel pressure was 36/44 psi when I checked a couple of days ago but I cannot rule out the fuel pump unless the pressure is still good and won't start. It stops so quickly, my gut says ignition. I can't fiddle with it right now so will check again tommorrow.

I was concerned that I hadn't found any real problem but had suddenly cured itself and I was right to be worried. I drove it to work for the last week and it performed without a hitch (aside from that goofy knock sensor code). Fuel pressure is good also. It decided to hiccup a couple of times @ 70 mph on the way to Green Bay (30 miles) and my sons wedding but otherwise worked normally. After the ceremony it decided it wanted to act up as before. Erratic idle, if it starts, and then will shut off if the hood is closed. It is sitting in the church parking lot and will investigate further tommorrow. I have a replacement ECM and Memcal coming from Mr. Finn. There are only a couple of things that will not set a code when acting up, coil pack/ICM, CPS as well as the ECM itself. It is also possible I have had vermin chewing on something unseen and have not found it yet.