2seater

Damn, I didn't notice you were a new member. As the others have said, welcome to the best forum on the net. There is s wealth of knowledge and help available. I don't know how long you have had your Reatta but I have not found the engine to be particularly smooth, hence the balance shaft Is the rough idle a new issue? What are the conditions for the city driving? Is the highway mileage considerably higher and how close is the readout to the actual calculated mileage at fillup? It can approach 30mpg in an extended run.

I do not remember if my ED17 will count above 255 or not? In any case, it shouldn't be a problem unless you see that number increasing while the engine is idling. It is normal to get a number of knock counts simply from the act of starting the engine. If the counts are stable while the engine is idling, tap on the engine lift bracket or on one of the solid mounts for the alternator or power steering and see if the number increases. It takes a fairly sharp rap, and may actually cause a change in the idle if the ECM pulls the timing back in response to the knock. If the knock counter is stable at idle, but increases with a tap on the engine, the system is operating normally. A sharp rap will cause the counter to increase by many numbers, not just a single count. By the way, I have found a couple of sensors that will read higher than the accepted "normal". I have seen air flow over 170 gm/sec and the BLM over 150 also. The O2 sensor can have a large influence on the fuel mileage if everything else is working reasonably well. Watch the O2 cross counts to see if the sensor is active.

I eliminated mine several years ago, and it will smell "gassy" under certain conditions as alluded to. The valve from the top of the canister was left connected to the harness and tied to the wiring for support. No codes or check engine light have ever resulted. The vacuum line from the engine was eliminated completely (custom aluminum vacuum block). The line from the fuel tank remains in the same approx. location with a small engine fuel filter attached to allow the tank to breathe and keep dirt out of the system. That line wouldn't like unregulated engine vacuum but it may be possible to route to the air intake near the filter if the pressure depression is very low. Probably wouldn't eliminate the free vapors completely. I don't see any performance advantage to eliminating the canister but it was a expeditious way for me to get it out of the way for the intercooler piping. Low priority but it will probably be reinstalled somewhare in the future. The ECM sees the valve electrically only (if otherwise isolated) and it just snaps onto the top of the canister, so I would believe that is all that would be needed if it is actually the cause for the code.

I'm guessing you are talking about the heavy rubber mounts at either end of the muffler? Mine does have some side to side movement if pushed and I do not see how it could not have "some" movement. I have not looked into their availability but I did add a loop of wire connecting the two bolts together to act as a failsafe if the rubber failed. The rubber is in good shape, but when I changed the muffler, I made the tailpipe from schedule 10 stainless steel pipe which is relatively heavy. The rubber loops that are located further forward on the exhaust system are readily available and are used on various brands of cars. I just thought of something. The rear hangers are fairly heavy but hang straight down. The forward hanger loops in the tunnel area are angled towards each other to provide some opposing side to side force. When I dropped the forward part of the exhaust to install a cat. the rest of the system moves very easily. If the muffler hangers look good, you might want to check the small loop hangers further forward.

I think a certain amount of fatigue sets in after the same questions are asked, over and over, but to be fair, the search function has never been the best. I agree that the welcoming of new members has become more and more sparse, and I consider myself as guilty as any. The way a member is received is probably more important than we realize. Sometimes a reminder that we were all noobies at some time can be helpful. At the same time, there are members that are tireless in answering questions, and the level of detailed knowledge of certain systems is better than it has ever been, plus the other reference sites (yours being one), did not exist many years ago, so the capabilities are also expanded. Good question.

That Ronnie is quick

The ALDL is located below the driver's side of the instrument panel, to the left of the steering column. It should have a black plastic cover on it. The face of the connector Ronnie posted will be facing straight to the rear. Please let us know if the cover is in place or missing.

Thanks Dave. As a matter of fact I talked with Mike this morning about tires for the Reatta. I have know both of the boys for a long time, but I never inquired about owner furnished parts.

The Rock Auto shims seem to work well. I did the same as you mentioned. I had an alignment done and then installed the shims to correct within factory limits. 1/2 deg on one side and 3/4 on the other IIRC. By the way, I had to buy two different brands due to availabilty of the correct angle, but they are exactly the same part, even though packaged differently. Buy the cheapest ones. Strange that the alignment shop says the rear isn't adjustable but the parts are readily available?

No easy way. The bracket has two screws up front, easy to get to. The rear is held by a single bolt, which also partially fastens the rear exhaust heat shield. I have found both 13mm and 15mm size heads on the bolt. The cables will need to be removed as well for best access. Pain in the rear for something so simple.

I do not know how much variation you have in the shading of the plug insulators but the air flow pattern in the intake manifold does cause the far end cylinders, 1&2, to be slightly leaner than the opposite end, 5&6. The effect is greater when heavy throttle is used regularly. It sounds like you are judging spark quality based on porcelain color, not the actual spark? Compression test?

Ahh soo! That is a clumsy looking thing with those odd shaped resonating chambers

I have used it for exactly that purpose without ill effects, although near the T/B over the exhaust, I generally added foil insulation. The air cleaner side of the engine compartment is probably the coolest area. 3" pvc (not ABS) and Fernco couplings makes experimenting easy.

The TPS does function as the accelerator pump would. It gives the immediate indication to the ECM what the throttle is doing. Without it, the ECM has to wait to see what the MAF and other sensors indicate has changed due to air flow and mixture feedback. It will run but be very sluggish to respond.

The regulator is not in the system if connecting directly to the pressure line from the tank. It should have no effect unless the connection is a tee to monitor the pressure before the fuel rail and the circuit to the rail and back through the regulator is still intact. The pump should be capable of 100ish psi if deadheaded as described.

If you do test the fuel pump ahead of the filter assembly, the "deadhead" pressure of the fuel pump should be considerably higher than the regulated pressure seen at the fuel rail. Probably about double or so, possibly more. I know I have cranked my regulated pressure over 60psi and with boost added, about 70 psi or so at the rail. Edit: I looked at the Walbro site for the standard pump performance curve and it exceeds 100 psi. My $0.02

The clearance to the balancer is not critical as long as there is "some" and it does not rub on the sensor when the engine is rotated. The head of the clamp screw faces straight down and is accessible with the front of the engine fully assembled. As long as there is a little friction on the sensor it shouldn't move if you choose the remove the balancer to lock it in place.

Not quite sure where the "middle bolt" is? The bracket is located on a pin that is installed in the front cover and can be a real pain to remove. You should be able to remove the actual sensor from the bracket by loosening the clamp screw that pinches the slide portion of the bracket together on the plastic sensor. It is used to allow the sensor to be moved to center the vanes of the damper in the sensor. It only needs to be tight enough to keep the sensor from moving in the bracket.

Welcome! You received good advice above and everyone here will try to help. I hope you enjoy the experience.

I believe Monroe calls the complete assembly "Quick Struts" but they do not list them for our Buick or siblings. You could buy the struts and have the assembly taken apart and reassembled with the original spring for your own installation, for a price. If you cannot do the installation yourself, you are probably better off using a garage you trust. You will need an alignment in any case.

Is this a new occurance? The speed is high for the deceleration fuel cutoff to be activated but it sounds like the same feeling. The other possibility is the torque converter is unlocking, which is normal.

I am only certain about the aluminum TPI manifold that I have in hand. The throttle blade is the same size as the one on the vin C. The vin C uses two discrete units, one for the throttle and the other for the MAF. The TPI has a one piece integrated throttle/MAF casting. I have actually adapted the TPI assembly to the C manifold and have used it in both N/A and turbo configurations. I used it for a the location of the IAC, not for any flow advantage. It gave me more room to route the turbo exhaust outlet below the throttle body. I do have a stock C throttle body that was modified many years ago by a guy on the Grand National forum. It is 2mm-3mm larger in diameter along with a new throttle blade, and it does flow more air. I have not looked at one, but the assembly on the L27 supercharged engines looks similar and may be larger?? The injectors I removed from the TPI manifold are Bosch 917's (last three digits) with a rated flow of 18.27#/hr. The stock C injectors I have are 901's with a rated flow of 18.55#/hr. I am sure that you are correct that there are larger throttle and injector combinations out there, but they are not part of the assembly I have. The only way to know for sure would be to remove the throttle and measure the opening at the blade and check the injector part numbers. I agree that the 170 gr/sec is due to the combination of MAF and chart in the ECM that reads it. I have flow tested both style MAF's to compare the actual CFM flow vs frequency output from the MAF and the stock C unit is almost a mirror image of the TPI one I have. IMHO the TPI manifold isn't a hi-horsepower manifold, but is designed to enhance the low and mid-range performance where the engine spends the majority of its time. The runners are actually quite small and vastly longer than the C manifold. I would imagine the newer TPI style manifold, a sort of curled up tunnel ram, particularly the plastic versions, have larger and smoother runners to aid the high speed performance. On an old, but related subject: I have always been curious what the maximum MAF readings are on some of the modified engines out there, particularly the Series I S/C engine swaps. About ten years ago I did get a couple of replies on the bone stock cars of 125-130 gr/sec. At that time I was seeing 137-138 on my engine: chipped, ported heads, larger T/B, exhaust restriction removed, no cat and cone air filter. Now, my bone stock original engine with the 1988 cam, cone filter, replacement cat. and straight through muffler shows 142 gr/sec, and 172 with 4-5 psi of boost. Model year, ambiant weather conditions and any modifications are important.

I don't know of a plug and play manifold for the C engine either. Anything to be adapted would require some work. Elimination of the EGR function would be a programming issue which I am pretty sure some of the S/C guys have faced. It would certainly seem to be the simplest solution. It will certainly work and run without it. The benefits, or not, of EGR can be debated but even in the modern era, it appears the OEM did it both ways. The aluminum TPI manifold will bolt on. The fuel line connections are both at the drivers side rear of the manifold so the fuel lines would need to be rerouted/modified or replaced. The fuel fitting size and thread are the same. The fuel injectors are the same size as the C engine. The thermostat housing is different and will require a different upper radiator hose. The steel line for the heater from the manifold is similar and the stock one can be modified or get the one that comes with the L. The connections for the TPS, MAF and IAC all plug in. The MAF uses the same frequency range as the C engine, and looks the same on the oustide, but is different where it inserts into the housing. The throttle, cruise and trans. detent cables all connect the same. To get the benefits of the L integrated PCV system one hole would need to be drilled in each head, or, an external system would need to be added. The L intake gaskets locate the hole required.

As far as I know, the operating system for later models with EGR is different. From the way I have heard it described, it is a single valve which is variable in nature where the C engine uses three discreet pintle valves with different size passages to vary the amount of EGR. I am not a programmer so I don't know if this hurdle could be overcome. I would doubt it. For some period of time, GM did not incorporate EGR at all, the aluminum TPI model is one example. The C engine is a two piece assembly with all of the passages in the base plate, but wether this can be adapted or not is unknown without a close examination. Perhaps someone with a later model may have an idea?

IIRC the equivalent cost of CNG btu's to gasoline was about $2.00/gal. The power density is certainly less, but it is less expensive when using home fueling (no road tax). I would guess, if more on-road fueling stations become available, the cost would be higher. It's part of the issue with alcohol fuels too. You use more but the price split isn't great enough to make it directly competitive with gasoline. There is a certain green factor that may make you feel better? I suspect we will see more development in this area. T.Boone Pickens has been touting this for several years, power the vehicles with natural gas and install a giant wind farm across the center of the country to power everything else