mdcc2010

Check belt tension first. Then, try to turn the compressor center hub by hand: if it's really difficult to turn, then it's likely running dry and/or getting close to the end of its service life. If your car has no power and wants to stall at idle with the compressor engaged, it would be in your best interest to quit running it: it's much easier to clean out the lines and replace a not-quite-dead compressor than it is to try to get all of the debris from a completely failed compressor. My RX-7's compressor was locked up when I bought it, so replacing it included removing all components and flushing them in addition to a rebuilt compressor, new o-rings, a new receiver/dryer (which should always be replaced with a conversion from R12 to R134 because of the dessicant differences) and a new expansion valve. ACDelco makes a liquid line refrigerant filter that will prevent any debris coming from a failing compressor (or stuck in the condenser from the last failure) from flowing through the rest of the A/C system and traveling to the compressor's suction port and hastening its demise; I installed one just in case (rebuild compressors apparently don't have the best reputation).

Sounds like you have it fairly well thought out already. I had a list of stuff I wanted to do, but I have four cars to keep up with ('87 XT Turbo, '91 Civic, '88 RX, '88 RX-7, in order of most to least broken) so it's kind of more a fix-what's-broken/get-it-running kind of game with my Subarus than it is a performance mod thing right now, especially since it's relatively difficult to get parts for them vs. my other cars. Ultimately I'd like to put a MegaSquirt system in my 'Rus with switchable boost/fuel maps, slightly larger turbo (probably another VF-series or a Garrett variable nozzle turbo if I can get one cheap), A2W charge coolers, and forged internals. I don't plan on pushing more than 180HP out of them (100HP/L is my ideal with most cars) so I'm not too worried about HG issues; RAM Performance may be able to supply more robust gaskets, so I'd check them out before I default to the Felpros. I'd also like to rebuild the transmissions and put taller 4th and 5th gears in both cars and a shorter Lo range on the RX (all parts sourced from 5-spd SPFI boxes). Of course I'd also need to rebuild the RX's LSD if I can find the parts... As for the spider manifold, yes it likely flows a bit better, but most of the benefits will be felt on an NA car because the engine has to work to pull air into the cylinders, whereas a turbo engine will be forcing an increased volume of air at a certain pressure into them; you'd probably only notice a real difference on an EA82T after extensive mods, so for me it would be an optional install once I have everything else built and the MS installed with a base map. I like being able to keep the spare tire up front on my RX because it wastes a huge amount of cargo space to keep it in the back, so I'll keep the flat manifold on it. Anyway, as I noted earlier, nobody has done a proper flow test or a dyno comparing the two manifolds on the same block, and the FSM for my '87 XT with a spider manifold and my '88 RX with the flat manifold both specify the same power numbers; it's not worth it to me. Also, the spider manifold has a different TPS vs. the flat manifold (spider has an extra wire or two and is more expensive), so that's something to watch out for; I'm not sure if one can bolt on in place of the other. Really it's kind of like the electric fan vs. clutch fan argument on my RX-7: a properly functioning clutch fan will draw no more power from the engine than an electric fan of the same CFM rating, and nobody has ever properly measured the CFM rating of the stock fan, so it's a crapshoot as to whether your new fan is close to the stock fan's rating. Plus, now your alternator will have to run the efan, transferring the power draw on the engine from the fan itself to the alternator. At most you'll gain a small amount of throttle response by ditching the clutch fan; at worst, you'll overtax your electrical system if you don't upgrade the alternator and properly wire up the new efan. If you do a huge amount of other mods at the same time (i.e, a rebuilt engine with loads of performance parts), then yeah, a conversion to an efan would probably be a good idea and help squeeze out that last ounce of power, however minute it may be. On its own, however, you won't notice too much of a difference unless you had a broken clutch fan to start with. If I were in a different phase of my life I would consider doing the dyno comparison stuff myself, but as it is I don't have the time, money, space, or other resources. Maybe when I'm out of the military I'll be able to do so... in 15 years.

I'm not an authority, but here are a few pointers: The clutch fan is primarily for the A/C subsystem, so unless you keep A/C, you can just delete it altogether and run only the main electric fan. If you do delete A/C, you'll want to replace the alternator with one of the double-pulley types if possible and run two belts to ensure the ancillaries are driven properly. If you decide to go with two electric fans, you'll want to install a higher-amperage alternator; search for "Maxima alternator" on here. Really it's a worthwhile upgrade regardless, but a necessity if you increase the demand on the car's weak stock electrical system. As for the radiator, the Spectra CU1099 is a full-metal dual-row radiator. It's designed for the XT and the top mounts won't line up properly on other cars (like my RX, anyway), but the mounts are just spot-welded in place so they should be easy to move compared to modifying an EJ radiator. The spider intake is cool and all, but it's kind of difficult to work with: it sits over a number of components, so you'll have to remove it to get to certain things (FPR, knock sensor, AAV, TWS/ECT) whereas the flat manifold is relatively easy. I have yet to see anything, but the ultimate test would be to build a good EA82T with the flat manifold and dyno it, and then swap on the spider manifold and dyno it. I don't think there would be enough of a gain to be worth the hassle unless you're running a fully modified setup already. If you're changing the turbo you may as well try to get a custom exhaust at the same time; you'll likely have to change the turbo flanges regardless, so a custom front and downpipe wouldn't be much more work. Try to improve the front pipe's flow (it has a T sort of junction at the RH head, which can't be efficient). Also, go with a larger diameter downpipe and try to get a freer-flowing cat while you're at it. You'll probably want a BOV. Unless you move to a MegaSquirt with MAP at the same time, you'll want a plumb-back type; the stock system uses MAF and you'll upset your AFR if you use an atmospheric BOV. There's a cyndrilical reverberator of some type off the side of the main air intake hose between the MAF sensor and the turbo that would be perfect for accepting a BOV return hose. Ultimately I'd like to custom-build an A2W charge cooler to sit where the stock air cleaner resides, with a remote radiator in front of the car or anywhere else with space and good air flow. I can't recommend anything prefab like a TMIC because I want to keep my car stock-looking. I'm all about being subtle with my speed, so I forego the stickers and scoops and loud noises and outlandish colors (though I do repaint rusty engine parts in GM Blue). Also, you'll probably want to look at a set of Delta cams (Torque or HP). I also like to experience things myself, which is why I don't really like my XT anymore. I still love my RX.

So I called the dealer and a replacement receiver drier is about $55, so I just ordered one through them; it's cheaper and more gratifying than playing internet store roulette (and AutoZone et al don't offer any at all). The part number I was given is SOA 438A216.

I've started restoring the A/C system on my RX, and it has not been an easy journey as far as parts go. Mostly this is because the system is Panasonic, which has a couple odd parts, namely the receiver drier: it has the pressure switch screwed into the drier body as opposed to most other cars (and the Hitachi system) where the pressure switch has a place on the refrigerant line between the condenser and the drier. I tried one (made by Metra or something like that) that looked correct and was specified for the '88 Panasonic system, but it is very wrong: the IN and OUT ports are reversed, its fittings are the wrong thread size, and it doesn't have a place for the pressure switch to be mounted, not to mention that it's taller and slimmer than the original so it wouldn't fit quite right regardless. Now, I can use the interwebs to find about 10 different drier models that say they fit this system, and they may look compatible judging by the right-angle flanges, but none provide any real information (namely about the port size, flow direction, and the pressure switch fitting) and I'd rather not have to buy all 10 of them just to find one (or none) that work. Does anybody know of a tried-and-true replacement? I'll call the dealer to see if they offer one with the new R134a-type dessicant for a reasonable price. The other part that can be problematic is the thermal expansion valve: the Hitachi system has a third, smaller refrigerant tube with a fitting in addition to the two main fittings and the thermal bulb whereas the Panasonic system lacks this third tube. Most places will say that the Hitachi valve fits the Panasonic system; it does not. I decided I didn't want to play with it, so I just replaced the o-rings and put the original valve back on since there were no overt signs of failure or contamination or anything. If I do end up replacing it, my '88 RX-7 uses the same style valve (I know because last year I restored my 7's A/C system), so I'll order one for that car instead. Otherwise, a generic HBNR o-ring set and R134a adapter kit are all I needed. I decided to use POE oil instead of PAG because the original compressor is still good and PAG supposedly doesn't like residual mineral oil and any chlorine that may have been left behind by the old R12 charge. I've already drained the old oil from the compressor and reinstalled it, flushed the evaporator and condenser, and replaced all of the o-rings. Once I have the proper receiver drier, I can oil up the compressor, evac the system, and charge it. I also modified the HVAC control so that I can run the A/C system (or not run it) in any climate control position.

My RX delivers around 30MPG if I keep it between 45 and 55 MPH on open road; over 60 MPH or in stop-and-go traffic, it goes down to about 24, which makes my RX-7 a better freeway car, surprisingly (it can deliver between 24 and 26 MPG at about 70 MPH). It's kind of disappointing. A fantasy of mine is to rebuild my transmission with the taller 4th and 5th gears from a 5-speed SPFI GL which would hopefully bump my MPG up to 30 at 65 MPH. Also, unless you're in Colorado or some other high-altitude area where regular unleaded is less than 87 AKI, or you live in a very hot climate and have noticed some performance issues and/or knocking, you'll only need to run regular fuel with a good EA82 turbo in a stock state of tune. These cars are designed and specified to run on 90 octane fuel per the owner's manual, which converts to 87 AKI here in the States. This is because these engines run a very low-pressure turbo (7 PSI optimum, fuel cut at 10 PSI) and are tuned very mildly from the factory (I mean, in the States it's only about a 15HP increase over a regular MPFI EA82). Even the FC RX-7 Turbo II is specified to run on 87 AKI, as are a number of other '80s cars with low-pressure turbos. However, if you up the boost or have a car that's been poorly maintained (or you're concerned the gas station you've stopped at has questionable fuel), you may get some knock on regular unleaded, at which point you'd want to go up a grade.

haha, yeah, when I tried to start it up the first time after putting it back together, it wouldn't fire without starting fluid before quickly dying. Swapping the supply and return hoses got it to run. This event wasn't the cause of the current problem since the car was having these issues before I tore it down. I'm not sure how the FPR stuck to the point where it won't pass ANY fuel. I'd guess it sat for quite a while without being properly stored before returning to service not long before I bought it. I mean, there were some dead vines that had grown into a few nooks and crannies in the underbody, so there had to have been at least a year of neglect involved.

I don't know who made it, or the OE number. The XT's pump is slightly different from the L-series pumps; visually they're nearly identical, but apparently there's a difference somewhere according to various internet sources that list parts for one but not the other. pskits.com sells a pump rebuild kit for the XT. According to my '87 XT FSM: *Output: 5.9 cc, 0.360 cu in /rev *Relief pressure: Turbo/MPFI: 924 psi Others: 640 psi *Hydraulic flux: 700 RPM: 7.4 US qt/min 3000 RPM: 2.6 US qt/min *Regular pressure: </= 142 psi *Relief pressure and working pressure: 853-1067 psi

A lot of cars don't NEED a catalytic converter to meet tailpipe emissions testing standards for their respective years (for example, Honda's CVCC engines were cleaner without a cat than most engines that had one), but they were federally mandated for all cars in 1983 regardless of an engine's exhaust stream content. If your car were tested to CARB and/or modern standards, it would mostly likely fail miserably. That being said, any car over 25 years of age is considered an antique and as such need not conform to federal NHTSA or EPA standards (though they may need to comply with state standards, especially in CA), so I'm not worried about restoring my XT's stock system from the aftermarket catless 2.5" turbo-back system installed before I bought it. Really, gutting a cat is really only a good alternative if yours is bad and a replacement is unobtainable or unreasonably overpriced (as many things tend to be for these cars, sadly). You may see a small improvement from doing so, carb'd or FI'd, especially on mid-80s engines that weren't originally designed for them. You definitely don't want to do it on a more modern car with a post-cat O2 sensor because you'll screw up your AFRs. Also, reducing the cat-induced backpressure on a turbo'd system can cause boost creep and/or overspool your turbo, so you may want to be careful if you're running with boost.

Still trying to get my XT's kinks worked out. So, after I put it all back together following a head gasket job a couple months ago (with new oil pump gaskets, reinforced cam tower o-rings, and anaerobic sealant for the cam tower-to-head mating gasket), I started it up and when it got to full temp it began making a light clink-y sound on the left-hand head. I wasn't too concerned at the time, but it steadily got worse over the course of a couple hundred miles: now it makes a very loud tick of death from just the LH head. Removing the valve cover reveals a normal amount of oil covering everything, nothing out of place and no noticeable wear from oil starvation or anything on the new cams, but all four lash adjusters are super squishy. When I put them in, all four had what seemed like a normal amount of play (sub .5mm). Has anybody had all lash adjusters on only one head up and fail before? Could it possibly be a weak oil relief spring or something like that?

I resoldered the majority of the connector pins in the ECU and checked for leaky electrolytic capacitors; unlike Hondas' ECUs, this one has only two such caps and they weren't leaking, so I put it back together and reinstalled it. That, plus checking the harness more or less ensured that the pump's circuit is OK. I didn't check fuel pressure with the aftermarket pump and the new tank (only with the apparently bad new pump and the old maybe-restricted tank), so I put the gauge on and ran the engine: pressure hit 80 PSI and pretty much stayed there until the fuel pump started overloading, at which point it dropped to about 50 PSI; no flow on fuel return at any point. It didn't seem to hold fuel pressure for very long after it was shut down; it dropped slowly over several hours from about 30 PSI, and I figured it was either draining back through the pump or possibly past the injectors, since it obviously wasn't going through the return hose. Removing the fuel supply hose from the engine and connecting it to a new FPR's inlet caused the gauge to register approx 36 PSI, with fuel flowing from the FPR's outlet when it exceeded that point. So it was (mostly) the FPR all along, which means I get to take off the stupid intake manifold collector to replace it :/ I'll probably test and potentially replace the coolant temp sensor (which may help my fast-idle problem) and also poke at the AAV to see if its shutter's sticking closed or something while I'm in there.

Thanks for the tip. There are one or two other random wiring issues to sort that will involve removing the carpet. The injectors seem fine; the car runs without too much trouble once it warms up. It's just that after it's been running at low speed for a while, it seems that the fuel pressure builds up enough to over-fuel the engine (i sometimes get puffs of white smoke when throttling up from idle) and cause the fuel pump to make racket. A few times the car has acted like it was flooded when started after sitting for a few hours, which excessive fuel pressure could cause.

I previously checked fuel pressure and it was a little higher than spec and didn't change much with the throttle applied. Fuel flows freely from the filter outlet when the pump is run. I would bypass the FPR and then run the engine to see if that improves anything, but the stupid spider intake manifold has to come out first, and since it's only $45 for a new regulator i'd rather replace it because it wouldn't be worth the hassle to tear it down, bypass the FPR, put it back together, test it, and then do another teardown/rebuild cycle to either return it to normal or replace the FPR. The more i work on these things, the more i prefer the old flat mpfi manifold.

So in my continuing XT saga, I'm still trying to get its fuel issues sorted. Symptoms were: noisy fuel pump after running for a few miles, runs fine at speed but with occasional stalls at idle, occasional flooding. Initially I thought it was the aftermarket fuel pump failing, so I replaced it with an OE pump. Then the car wouldn't start and was receiving zero fuel at the engine, so I figured the tank was plugged (there was some rust in it, and it had been sitting for a while before I bought it). In went a new tank, but still no fuel to the engine. Turns out my new pump had failed, so I put the aftermarket pump back in and it started, but the same symptoms remained: noisy pump, random engine roughness, flooding. The only thing that hasn't been replaced is the fuel pressure regulator. Removing the fuel return hose at the engine and running the pump results in zero flow from the return pipe at the engine, and there's still no flow out when the engine is running, with or without vacuum applied to the FPR. Anybody have a FPR just completely restrict flow before?anything else I should look at?

Thanks for the cam note. I'm perfectly accepting of a lopey idle and a little noise (this isn't a BMW 7-series, after all), but I don't plan on daily drivering this car, really; I'm not even sure I'll keep if for long once it's back in a relatively decent state mostly because I don't have the time, training, or facilities to properly fix the body imperfections and repaint it. It's structurally sound and doesn't have enormous rust holes (except under the battery), but it's still going to be a lot of work to make this thing pretty again and I just can't do it myself right now. Even having someone else do it around here was quoted at about $20k and a year or more to complete it (this includes completely stripping the car, media blasting, rust correction, body work, multi-layer paint, and reassembly). I figure I may let someone else have a go at it if I move again; I'd rather keep my much more versatile RX if anything. Anywho, according to the FSM's fuel system diagram, there's a strainer in the tank in addition to the little screen on the pump inlet. It's not mentioned anywhere other than in that diagram. It's possible that it's an error, but I'm inclined to believe it since it would make more sense having a strainer with a large surface area as an initial filter rather than the tiny inlet screen on the fuel pump be the only thing there. I couldn't get the car to start at all today and removing a the fuel return hose on the engine showed zero flow even in Test Mode with the fuel pump cycling. There's still fuel in the tank (4 bars on the digi-gauge), but removing the supply hose from the tank results in nothing flowing out. Looks like it's totally clogged, so it'll have to come out. Since I can't remove the strainer to keep it from being damaged or sealed up, and because it's a perfectly huge pain removing the tank in the first place (diff + muffler must come out first), I think I'll buy a new one as opposed to attempting to de-rust and reseal the existing tank. edit: yes there is fuel in the tank: about 1" of it visible through the fuel level sender aperture; somehow the fuel just isn't getting to the pump.