2seater

The one thing to watch for in the conversions is if any parts are marginal, the higher pressure in the 134 system may cause a failure. Just happened to a friend of mine on a '93 Buick. It cooled very well but the compressor seized after ten days. If the system is just a little low, I agree that sticking with the R12 is a better deal.

Is the TPS reading 36,.36 or maybe 3.6? With the key on, no need to start the car, enter the diagnostics again and watch the TPS reading, ED01, as you slowly press the throttle to the floor. It should increase relatively smoothly to over 4.0 volts with the pedal to the floor and return to around .4 volts in the idle position. All the other readings look pretty normal. To get the O2 sensor warmed up a little better, bring then idle up to 1500 rpm or so and hold it for a little while. The O2 sensor should start showing cross counts after it gets hot enough. It's not unusual for it to get sluggish or stop during an extended idle.

The first thing to do is check the actual pressure with a mechanical gauge installed in place of the sensor. The oil pressure senders do have a history of going bad and will usually peg out to the high side at random, but they can give a false reading in other ways. Hopefully it is just a bad sender.

Very nice work and a great addition. I like the look a lot.

Evidently there may be some differences in the error codes for different years, but my '90 manual indicates the E026 is the quad driver circuit. The quad drivers are in the ECM, (essentially transistors I believe), and they do control several items, the EGR being one of them. I thought the '91 went to a somewhat different operating system for the EGR although that may be in error. the B335 appears to be for the heating/cooling/ventilation system. If it was current code, the system would likely not operate and diagnostics could not be entered either. Not a lot of help.

I don't have enough resolution to actually read that boost gauge but I suspect it may be reading vacuum. My boost gauge looks similar, 0-30" vacuum on the left side and 0-20 psi boost on the other. I don't know about your car Greg, but my turbo won't really build any boost until I load the engine. It's one of the significant differences between the S/C and turbo, the S/C is directly coupled to the engine so it will spin up based on rpm, where the turbo needs a load on the engine to generate the exhaust flow to spin up the turbo, but once that happens, there is more and more boost available. Thanks for posting Reattadudes pics.

The word "tale" was probably a poor choice of words, no offense was intended. I do know they did exist, one was crashed but if it was repaired or not is unknown. The others probably survived, as you indicate. How and where they were disposed of continues to be a mystery. I do remember the photo of the gray one with the different front end treatment. Nicely aggressive looking without being gaudy. Maybe they will appear in the light of day when the value is such to make the owners want to cash in. It is interesting you mention the "stripper" version. If the Reatta could lose a few hundred pounds it wouldn't need much more motor. Just getting the weight down to about 3000# would be equivalent to adding about 20hp.

It sounds more like it is running out of fuel. If you can put a fuel pressure gauge on it to tape to the windshield it would give a good clue. Once upon a time we were trying to track down a similar problem and it turned out the rubber fuel line from the fuel tank to the steel line in the frame would collapse under the suction of full throttle acceleration and would recover when the throttle was reduced. It essentially accelerated fine until the fuel bowl emptied. Another possibility is the fuel level is too low and there isn't enough reserve capacity until the pump catches up. A low fuel level will usually exhibit poor off idle performance as there is a big hole to cover until the main system starts to work and it runs out of accelerator pump shot. Just a guess.

It is impossible to tell how the piping underneath is routed. That was a problem that confronted me also. I could not find enough room to route the rear manifold exhaust up to the turbo and still have enough room for a down pipe back through the same area. If you look at a Reatta, it gets very tight at the drivers side rear corner of the engine, near the anti-lock stuff and all the cables that connect to the throttle. I resorted to making a new rear manifold, located higher on the head and the exhaust from the rear is routed around the passengers side of the engine and joins the front manifold, essentially the same as the stock routing only reversed. The downpipe from the turbine outlet is routed out through the stock location and outlet to connect to the exhaust in the stock position, just below the newly created rear manifold. All of the stock exhaust system bolts up as if it were unaltered. They may have relocated some other items that are unseen. My install has all items except the air box and vacuum reservoir in the stock location. I saw a photo at one time, probably the ones in the article about the turbo Reatta's, and there appeared to be a crossover pipe in the same location I described. This was after I had already done mine and sorta validated what I found to work. It's true an s/c installation would likely be easier, since most of the hard stuff has already been done, except for the ECM and other control system items which both systems will have problems with and still make a Reatta fully functional in the electronics area. The turbo has more total power potential and is way easier to change the boost level, but the full power really can't be used unless all sorts of other upgrades are done as well. The Reatta is a nice car in stock form unfortunately it died before the later model 205 hp versions of the N/A 3800 were available, which would be a nice base engine for the weight and something like 250-300 hp for a high performance(GS)version would be just about perfect. Just my opinion.

Yeah, that tale comes up every once in a while. From the articles on the subject, there were three different prototypes, a low boost fwd, a high boost fwd and a high boost rwd, esentially GN running gear. At least one of the proto's was crashed by one of the press corps. The others may still exist somewhere, but they would likely be like the ones donated to schools, not available to the public and probably no titles either. Barney probably has a better handle on these cars.

The turbo install looks pretty similar to mine, in the same location but oriented differently. The compressor side of the turbo sees about the same heat as the coolant water, so burning it shouldn't be a problem. He could have used the other model of formed upper hose that would clear the turbo better, but with chafing protection it's probably fine like it is. The stock system handles 5-6 psi of boost without real problems and the aftercooler would be nice but not absolutely necessary for low boost. Even that level of boost will add 30%-40% to the hp level, a very noticeable increase. It would be on the edge of the stock fuel system, but the installation looks pretty close to what GM did back in the late '80's for the turbo prototypes they did. They do not exist anymore as far as I know, so this is not factory.

If the o-ring is leaking at the intake end of the injector it will cause a vacuum leak and probably a high idle. If leaking at the fuel rail end fuel may dribble out and if it is very severe it would drop the fuel pressure, but I would believe it would take a large leak to do that. The o-rings are pretty reliable if they haven't been disturbed. They are replaceable by themselves, no need for a new injector. On the other hand, if the injector itself is leaking, it will need to be replaced. If spark is normal and the injector is bad, it will react the same way as a dead cylinder due to lack of spark. When you did the spark test, did one cylinder seem to have little, or no effect on the idle? Maybe the one with the suspect injector?

The injection system is essentially the same and will work fine. The intake manifold itself is what is different. The fuel rails and some other component locations will be different too, not due to differences in how it works but due to the shape of the manifold. The differences will be readily visible if you compare the two. The only manual transmission I know of on this forum is Greg Ross and "Betsy Blue" and he has posted the details of the swap, which should turn up if you do a search.

The front stabilizer end links and bushings that hold the bar to the chassis should be looked at. When they go bad they make a very annoying clunk.

That's a pretty big change, 20 something percent. The sweet spot for cruising is usually around the engine torque peak, about 2k rpm or so. That will put the sweet spot down in the fifties for speed. These engines don't need to spin as fast as the Chebbie's, they are a different animal. I believe the '91 Reatta's with the effective gear ratio of 3.25, relative the '88-'90, have generally poorer fuel economy, although performance is somewhat better. Even the Grand Nationals only ran a 3.42 ratio with the same size tires as ours. Mileage aside, it sounds like too large a change unless there are engine modifications to take advantage of turning a lot more rpm. You could approximate the change by driving at your normal highway speed in third gear (no overdrive).

It's good to hear you have the problem solved and also the report on the fix. The no spark and fuel are loosely related. When the engine is cranked the module generates the spark signal after it synch's with the crank position which tells the ECM to start fuel flow. No spark will likely result in no fuel either.

It sounds like you have all of the knowledge necessary to make a decent system, but be wary of making it too large or low end torque will suffer. From the little bit that I know and some studying of zero loss exhaust systems, the rule of thumb is 2.2 cfm of flow per horsepower and flow through a straight pipe should be approximately 115 cfm per sq.in.@ 20.3" of water, or 1.5 in of mercury. I tested the stock catalytic converter and it flows 223 cfm at that test pressure, and it doesn't matter which way it is flowed. I don't know if a high flow cat. really does what it says, the matrix would have to be larger in cross section or a different design for better flow. If actual flow for the cat. were listed, it would make selection easier and Dynomax is one of the few muffler manufacturers that list actual flow and horsepower ratings. If you look at their website, you will see there is a huge difference in flow capability depending on the design, even in the same size case and pipe diameter.

The single turbo has been installed for two years, and is my daily driver for six months of the year. I have the same issues Greg Ross has with his S/C, a control system for boost and timing where none existed before. I should take an updated photo but if you right click on the photo to the left and add to favorites, you can click on it in favorites and blow it up. Average mileage is 25 mpg over a 70 mile commute each day. Performance is good if limits are observed. More tuning this summer.

You are probably better off leaving the car sit untouched rather than driving it a few miles once in a while. I'm not sure what "syrupy oil" might be, since that describes it's natural state to me. Short trips are what is hard on the oil since it doesn't get up to temperature, especially if this was over cold weather months. The debate between dino oil and synthetics rages on. Full synthetics are superior in every measurable test, but the question remains, does the engine really need it? Personally I run it in everything I have owned for ten years, no matter if it was new or I purchased @ 125k.

Tapping the brakes will disengage the torque converter clutch and it will take a moment to re-engage, especially if the throttle was also closed, which drops the TPS voltage below the clutch engagement threshold.

From what I have seen in the salvage yards, particularly the tuned port, or snakes type manifolds, could likely be interchanged, but a lot of other accessories on the manifold itself would need to be re-routed or changed to the later model parts. The water outlet was in a slightly different place, the EGR, if it had one was different, and the fuel rail was completely different, making hookup of the stock lines a problem. The tuned port manifold style is available in a completely aluminum casting also, mostly on Oldsmobiles for some reason, in the '89 and '90 model years, but not on all of them?

Welcome! The Reatta drivetrain is pretty robust and is common to many full size GM fwd cars of the same era. It can commonly go a lot of miles with normal maintenance. The electronics can be a devil if they go astray. Most of the engine electronics are not specific to the Reatta, so parts are commonly available, the interior stuff can get more model specific, but most is shared with some other vehicles in the large car family, particularly the Riviera's, which is pretty much blood kin under the skin. If the brakes are working properly but you do not know the maintenance history, get the brakes flushed. Get a factory service manual, it will pay for itself. All of the glass is rare, or at least hard to find, and is very expensive. There are two people on this forum that can help with missing or broken parts and assemblies, both are stand up guys, and can help with fair pricing.

Replacement of the pan gasket takes maybe an hour or so, once up on ramps or stands. The only thing that must be removed is the plastic cover over the bottom of the flexplate. The FelPro gasket is pretty good and mine came with plastic "studs" that screw into the corners of the block. The oil filter adapter is somewhat in the way but you can work the pan around it. The plastic studs are split down the center so when the pan is pressed up over them they snap partially open to allow the pan to hang from the them and get the gasket nice and straight and then just push the pan up loosely against the block to start all of the bolts. The plastic studs just screw out with your fingers. If you choose to remove the oil filter adapter, which takes a bit longer, there is an extra bolt hole in the pan that is normally covered by a heavy metal bridge because a bolt in that position would be blocked by the filter adapter. A bolt can be added to that position if desired but not normally necessary.

It uses a two piece rubber lip type seal, at least that is what I received in the Fel-Pro set. The older rope seal could be changed with the engine in place, and the '90 FSM shows a rope seal? The manual also recommends engine removal. I suspect the "Y" shaped block with the crank embedded in the block would make changing the seal in place very difficult if not impossible. Hopefully someone else with actual experience doing this will enlighten

The subframe does not cover the oil pan. The plastic inspection cover at the transaxle does cover a few bolts but it is easy to remove. Oil pan gasket replacement is not a big deal at all.