2seater

It is welded with a resistance weld in a ring around the expanded portion of the pipe at both ends. If you look closely you should be able to see a depressed area where the weld is. I have found a chain type exhaust cutter works pretty well if you cut just next to the weld on the side away from the converter. The converter has a heavy wall pipe inserted into the expanded portion of the exhaust, front and rear and you don't have to cut through that, only the first layer of pipe next to the weld on each end and the weld will come off still attached to the converter pipe.

I must say I am a bit disappointed in the gas recharge method. I for one would like to see much smaller diameter thread diameter where it pierces the ball. I looked at some engineering files for thread strength but cannot claim to have learned anything definitive except the old school guideline for thread engagement of one diameter is still a good approximation, or 1.5 for softer materials. A smaller diameter comes much closer to the desired engagement and also reduces the surface area under pressure. Some form of o-ring seal would also help with a gas tight seal.

I have toyed with that idea for a while now. I do not know if it is practical in this instance but there are some vehicles that do have a hatch to access the top of the tank. I know the reason I have thought about is due to the condition of the supports and other associated items that would be disturbed while dropping the tank. There is no doubt dropping the tank would open a whole new can-o-worms. To be clear, this is only considered on a somewhat derelict car, that is in poor shape underneath.

I don't have a '89 FSM but I do know for certain that the original pistons in the '89 engine I have on my stand are 1.5mm/1.5mm? When I rebuilt it I used later model pistons ('95 I believe) that are 1.2mm/1.5mm. Frankly I wouldn't sweat the end gap too much. Much better than too little. Any idea what the other cylinder end gaps look like? The rest of the engine also has an undetermined amount of wear so my opinion is, do what you need to and run it until you replace the engine. I have had to replace a single piston on a couple of different engines, 283 Chebbie and 199 straight six AMC many years ago, and neither received any extensive machine work other than a bottle brush hone. Is it the best, of course not, but it will float the boat and you will likely never know the difference. I'm not quite sure why all the fuss about ring end gaps. The motion studies I have seen indicate the rings rotate in use although the original stagger may be maintained?

It's relatively cheap, but still a good idea to save your money. I imagine this simply spoofs the air inlet temperature sensor which may cause a slight timing increase. This may have a small improvement in the feel at low speed but usually has other non-desirable side effects. Interesting how poorly written the claims are. In one place it mentions over 18k sold and further down, it states 15k? While the '88-'90 engine control systems are essentially the same, the '91 engine and controls are different. It seems very unlikely GM missed a simple item that improves both hp. and mileage. This is the inlet air temperature chart.

Thanks for the information. I sort of expected there to be a compromise due to the wide operating temperature. I would think it would be way low when the temp. is 100 degF. colder than the 70 degF reference, although it wouldn't stay there as the engine compartment warms up. The Hydac site figures I mentioned were for a storage vessel. I do understand there must be a balance for capacity vs pump cut-in, but the extremely wide pre-charge pressure standard per the Teves instructions seems pretty loose. Sorry for the detour. As another neighbor to Green Bay, along with Dave, the only thing I can say, after the national undressing in five minutes, is I think the conversation with the team would likely be different if the team had a conventional owner. I also heard rumor there was a local petition to shorten games to 55 minutes.

Not to muddy the water, but something has been bothering me about the pre-charge pressure in the accumulator. In water systems, the pre-charge is generally near of just below the pump cut-in pressure. I thought perhaps hydraulic accumulators, at the considerably higher pressure, may have different rules, but Hydacs' information on the subject states 0.9 x operating pressure? That would be 1800 psi if related to pump cut-in? Perhaps actual minimum safe operating pressure is lower, but the pressure switch setting seems to indicate 2000 psi minimum? The 1000psi pre-charge sounds like a better match to the older Powermaster systems? Hydac also has a note that the gas pressure will vary depending on operational temperature so with underhood temperature variation of 200 deg.F, or more, maybe there is some margin built in? Am I missing something?

Does the courtesy light in the drivers door work? Also the inner bulb of the rear turn signals, the third one from the outer end? If the fuse is good, it sounds just like the splice under the drivers seat I repaired on mine last year. Also thanks to Mc_Reatta for that one.

I wonder what the actual pressure is when they go bad? Four seconds isn't much time to build pressure. I have been following this thread with interest. The Amazon supplied accumulator I purchased last year made almost no difference in the reserve capacity, so my assumption is the charge is low even in this standard replacement accumulator. I have (4) accumulators on hand, and all will only supply one to one and a half applications before pump start and I know the pressures in the system are spot on. The 24 year old one on my '90 fluid drop is approx. 5/8" and one pump to pump start. The new one from Amazon yields 1/2" fluid drop and just over one pedal application. Did anything ever develop on the possibility of a recharge?

I'm glad you chimed in Padgett. The curves for the early years shouldn't all match and I hope your resources are better than mine. Unless I have the only '88 cam with more lift and duration, especially at higher lifts, something is incorrect. I looked at the '87 LG3, which is the direct predecessor to the LN3, old style intake and heads, but roller cammed etc.. The curve looks essentially identical to the '88-'90 ones presented, but at a lower level, 150hp and 200 lb/ft. I certainly agree that more modern tech. feels quite a bit different, but that old low rpm cruise is hard to beat for soothing, although lazy feeling by comparison.

Yes, I thought the same thing. I want to do a little more research to find some evidence of difference between the first and second year availability. I know I installed an '88 cam in my '90 engine and it definitely pulls to a higher rpm. I know the heads will flow more at higher lift, like the '88 cam, by testing on my flow bench. Everywhere I have looked and posted on engine forums have come up empty. It is simply not possible that the two cams produce the same engine output. From evidence I have seen comparing acceleration rate vs power curve, maximum accel. rate is at the torque peak in any curve. Interesting that the 2000 rpm torque peak on the early graphs also coincides approx. with a 70ish mph cruise, but it is unclear if that is where the engine is most efficient under partial throttle, ie. vacuum.

I found the related engine power curves for the four years involved. Pretty easy to see why they feel different. There is no doubt in my mind that the identical curves for the 88-90 cannot be correct, but the 2000 rpm torque peak indicated matches what the FSM says for the '90. It would appear the '91 gearing was likely changed to better match the higher rpm torque band. From other information that I have seen posted by Padgett, the '91 cam is even milder that the '89/'90, maybe why the max hp. rpm is higher for the early engines?

Repeating the same numbers over and over doesn't sound like what I normally see, although a somewhat large swing from high to low sounds familiar. I don't know if it has anything to do with the update rate of the display and/or ECM or not? As long as it swings back and forth around the theoretical optimum, I look more at the cross counts. What do the Integrator and Block Learn readings look like? They both should settle at approx. 128 if everything is operating in harmony, but some variation above and below is pretty normal and I believe the amount of ethanol in the fuel will make the BLM trend a little higher. It also needs to be after the engine is fully warmed up. How is the fuel mileage?

There is no single correct reading, but it is designed to indicate in a range. The .80v would be on the rich side and the .12v is lean. That information is sent to the ECM which adjusts the injector pulse width to try to bring the reading to the stoichiometric value of approx. .45v. The more active the sensor, the better. Cross counts is the indication of how often the O2 sensor changes from rich to lean and back. The system is constantly adjusting on the fly as it should.

I saw an article on the EDM removal of broken parts somewhere also, and would seem to be a good solution other than cost and shipping if required. It would be a shame to trash an otherwise good block for a couple of buggered holes, but the cost to repair may be prohibitive. I would think a good machine shop would know of a reasonable solution since they likely run into this often. I saw the comment about rods being out of round, assuming the big end, but I haven't seen evidence of this on the few 3800's I have had apart. Maybe outside my ability to measure? This is a relatively low rpm engine so I would think stresses would be low? Relative to the bad cylinder, a bottle brush hone and re-ring for a single cylinder for a quick fix, okay, but if the cylinder appears to be out of operation for an extended period, I would look elsewhere. It would have to be pretty bad ring seal to not run at all. Bad valve seating, maybe sticking, or possibly a rocker arm issue might lead to poor compression, or possible headgasket? Dead cylinder for other reasons would be injector or spark.

The photos likely don't show as well as in person, but the 3/4 front shot looks like plain old black steelies, like it has four spares in place. I think I get the vibe you are after but somehow everything just "fades to black" and the detail disappears.

Agreed that the easy/cheap route was not the best choice of words, also inaccurate. I do appreciate keeping a derelict on the road but the LS transplants are just too common. I guess it's just a personal bias to admire unconventional, or even impractical, solutions.

Some nice touches but I must agree as soon as I see an LS engine under the hood my eyes glaze over and think they took the easy and cheap way out. Their choices of course but this is an unfortunate return to when everything was SBC powered, the bellybutton principle. The LS IS a fine engine, but it certainly isn't a Chebby engine. It has cues from other makes, including Ford and Buick, and almost no SBC. Even a blown 500 Caddy would have been better, but that's just me.

Does the pump run and then shut off? Pull the connector on the pressure switch and check for seepage of brake fluid into the connector.

Odd that the modulator would leak externally? Usually if the diaphragm goes, the engine starts to ingest trans. fluid through the vacuum line? If the vacuum is disconnected and the line is plugged, the transaxle fluid pressure should go to maximum to achieve the firmest shifts possible.

I think it is a worthwhile experiment but only time will tell if it is superior. IMHO the rotating wire bundle design from the factory is flawed because of the lack of strain relief to aid in rotating the bundle instead of using the light connector to apply the force.

IMHO the wire runs are sort of six of one, half dozen of the other. I certainly agree that keeping the runs as short as practical is a plus, but it is relatively simple to use a heavy gauge wire from the B+ to the relays. Heavy wiring to the headlights is a little more problematic since it must have a certain amount of flexibility to move when the doors rotate. Of course the wiring can be downsized near the lights, or the jumper harness can be used as suggested. Adding splices or connections introduces the possibility of voltage drop in themselves but careful assembly should minimize that. In my case, I used the factory style wiring using the yellow drain wire from the headlight module which is on the drivers side so my choices were more limited. It looks like satisfactory operation can be achieved without the drain wire so the choices are more open. It would seem the relays located between the headlights with heavy feed and ground to the relays would offer the best compromise electrically?

Great news guys. I would bet the drain is through the coils, as proposed, and since it is relatively high resistance, compared to the headlights, it takes a while to drop the relays out. I seem to remember something like that in the journey last year but the click seemed to be from the module? Very curious. As long as it does that dependably, I think you found a good solution that really does plug n play. Could maybe add the resistor as suggested previously to lower the resistance. Did it help the headlight performance Ronnie?

Pretty straightforward. Remove the single torx screw and the entire housing pulls out so the socket can be removed from the rear. If memory serves, it's a 194 style bulb. I installed the LED equivalent and am pleased with the results.

That all sounds eerily familiar. Hard to get a handle on what to change when the operation is erratic. I know your lights are LED, hi and low, so this shouldn't make any difference, but try putting your lights on high beam and then shut them off. When I was doing the relay mod, and mine were acting in all sorts of strange, seemingly random, ways, mine worked normally when shutoff on hi setting. It may have been the mismatched relays at that time, or something in the circuit changes when the hi-low relay in the console breaks contact. Do you run with fogs on as well? Remember the guy that had luck with the retract if the fogs were also on? Maybe one or the other will give temporary relief.