How-to Rebuild Fuel Injectors

Posted on June 28, 2013 by RJ

Do your fuel injectors need a refresh? Here’s how to rebuild them.

First, you need to buy a rebuild kit. This will include the filters, o-rings, pintle caps, and spacers required to rebuild your injectors. I bought my kit on eBay. If you just want to replace the o-rings, you can buy a “seal kit” instead, like this one.

Next, you need to gain access to your fuel rail, pop off any retaining clips if you have them, and then remove the fuel injectors themselves.

BMW M50 Fuel Injectors & Rebuild Kit

Now mount a wood screw (included in my rebuild kit) that is just large enough to fit inside the injector opening on a vice. Fuel injectors have small, integrated filters inside of them that can clog over time. We will be replacing these filters.

Wood Screw

Carefully thread the injector onto the screw until a few threads bite in, then pull the injector away from the wood screw until the filter comes out. This might be difficult.

Fuel injector threaded onto wood screw

If you are successful, you should see this:

Removed fuel injector filter

Repeat for all your fuel injectors, in my case 6. At this point, you can optionally clean your fuel injectors using fuel injector cleaner. I may cover this at a later date, but I elected not to clean my injectors this time around. Cleaning is a more complicated process – some people have even built elaborate cleaning rigs to pump fuel injector cleaner through the injectors automatically!

Now *carefully* remove the pintle caps and also remove the o-rings. Do not simply yank the pintle caps off with pliers as it is possible to damage them.

Pintle cap, o-ring, and spacer removed

And then remove the o-ring from the other end.

O-ring removed

Installing the rebuild kit is simple. Start by installing the new filters. They simply press into place – use a tack hammer to lightly tap them in until flush. Then install the top o-ring by rolling it onto the injector. Finish up by installing the spacer (if needed), o-ring, and pintle cap on the bottom of the injectors. The pintle caps easily snap into place and hold the spacer & o-ring on.

Rebuilt injectors

Finally, reinstall them on your car!

Newly installed fuel injectors

Happy motoring!

BMW M50 Power Steering Delete Belt

Posted on June 27, 2013 by RJ

My e30s both have their power steering deleted, but the M50 from the later e36 uses a serpentine belt that drives the water pump, alternator, and p/s pump all at the same time making impossible to “just remove the belt” to prevent the p/s pump from running like on the old M20 or the early M42. However, there is a solution – by completely unbolting and removing the p/s pump from the M50 a different, shorter serpentine belt can used with an alternate routing to effectively delete the power steering. You should not run the p/s pump without fluid. Different part numbers are thrown around, generally ranging from a 6PK1400 to a 6PK1415, with 6PK1410 in the middle. Let me decode those numbers – the first “6” means the belt is a 6 rib serpentine belt and basically determines the width. This stays constant. The last four numbers are the belt length in millimeters, making a 6PK1400 belt 1400mm long. That’s simple enough.

I kept my idler pulley (the one above the alternator) and successfully fitted a 6PK1420 Serpentine Belt from Advance Auto (Part # 560K6). This belt, as mentioned above, makes it 1420mm in length. It was a snug fit, but not quite as tight as the factory belt, so I’m sure a 6PK1415 could also be used. Some people elect to delete the idler too and use a shorter belt; I would recommend keeping the idler as it gives the belt more grip on the alternator & water pump.

10 Useful Tools Every Mechanic Should Own

Posted on June 26, 2013 by RJ

Tap and Die Set

Craftsman Standard Tap & Die Set

Tap and die sets help keep your projects on track. When a cross threaded or rusty fastener threatens derailment, a die will clean the threads right up! Taps make for tidy and convenient fastener solutions rather than using a through bolt and nut. I even tapped my Holset HX35 turbo so that I could use an off-the-shelf oil feed. This is a tool that is useful to more than just mechanics and can be used for home repairs and other hobbyist projects; I also tapped the custom backplate on the 8mm projector rather than use nuts. (Note: While I linked to a Bosch tap and die set, I personally use a Craftsman set. Craftsman has recently switched to Chinese production and the Bosch set looks to be a quality set.)

Pickle Fork

Modified pickle fork

Pickle forks are generally used to remove spent ball joints & tie rod ends that will not be reused (because the fork often destroys the dust boots). On the BMW side, many people elect to use a ball joint puller instead of the pickle fork, but I find ball joint pullers take longer to perform the same job. Ball joint pullers also deprive you of the stress relieving satisfaction of beating the living tar out of your car :-p In addition to ball joints and tie rods, I have found many other unexpected uses for my heavily modified pickle fork. Combined with the power of the BFH, almost nothing is safe from ~~destruction~~ removal! This often useful at the junkyard where preservation is not a priority. From windshield wipers (who needs a special removal tool now!?) to ECU box lids to master cylinders, I have leveraged the powers of my pickle fork.

B.F.H.

Four pound hammer

No self-respecting mechanic would ever be caught without their B.F.H. If you don’t already know, BFH is short for “big [expletive] hammer” and they are used to beat things into submission. Exhaust needs “adjustment?” How about that axle that just doesn’t want to seat? Caution must be exercised when using the BFH to prevent unwanted collateral damage.

72-Tooth 3/8″ Drive Ratchet

72-tooth Kobalt ratchet

For years I used coarse tooth (30-32 tooth) ratchets and worse yet, I often used very cheap ratchets with the exception of an OG ⅜” Snap-On ratchet. Let me tell you – if you have not used a 72-tooth or better fine tooth ratchet, try one immediately. More teeth means the ratchet requires less movement before it “clicks” into the next position making work in tight spaces much, much more tolerable. I’ve been using a Kobalt ratchet that I paid around $30 for and it has been worth EVERY PENNY. Keep in mind that most fine tooth ratchets will break under less torque than their coarse tooth cousins, so keep a breaker bar or cheap ratchet around.

Deep Socket Set

13mm Craftsman Deep Socket

My first experience with deep sockets came when I received my Craftsman toolkit as a gift. Ever since that moment, I have hardly ever put them down – especially the 13mm (pictured) and 10mm sockets. The make short work of nuts on threaded rods and also work pretty well on your standard nuts and bolts. While the slip off a bit easier, they act like a short extension and leave knuckle room. If you don’t already own a deep socket set, I highly recommend you pick them up!

Vise-Grips

Well used Vise-Grips

Vise-Grips are the ultimate in infinitely useful tools. Buy the Irwin “Vise-Grip” branded vise-grips as they are the best quality on the market and you will use them in ways you won’t believe. You will often see vise-grips being put to use in my DIY articles; one such example is when I used them to hold the Porsche 944 booster rods in place while the rod was being threaded with the tap and die set. They are useful as extremely versatile and strong clamps, pliers, etc and can be used to muscle parts into position and hold them their. I found them extremely useful while installing the swaybar in my e30 – I used them like pliers to pull the brackets together and then locked them in place to clamp the brackets together while I installed the sway bar bracket bolts.

Bench Vise

Wilton “Shop King” Vise

A vise is another tool everyone, and I mean everyone, should have. Vise’s are great when you absolutely need to hold a part in place for cutting, filing, sanding, welding, and so forth. Vise’s transcend auto mechanics and are also useful for arts and crafts, home repairs, bicycle work, and more.

Angle Grinder

Cal-Hawk Angle Grinder

Another destructive tool, I have found the angle grinder to be among my most used power tools. I originally bought my angle grinder to cut and shape exhaust tubing for my 540i, but have hardly put it away since then. When I parted a rusty Oldsmobile Bravada, I used it to cut the transmission crossmember out of the way and gain access to the transfer case. Any time I do exhaust work, I buy new hardware and just cut the old hardware off (it usually breaks anyway from being seized) making the angle grinder a huge time saver. The 944 booster even got in on the angle grinder action when I shorted the threaded rod after extending the threads. Think of it like a hacksaw on steroids, all for the low, low price of $30!

9. Dremel MultiPro Rotary Tool

Dremel MultiPro Model 395

Dremel’s are such a quintessential tool that the very name has become a verb not unlike Google or Xerox. As the above illustration clearly shows, my personal dremel has been heavily used through the years and now wears its grime and battle scars with pride. I commonly pair it with the reinforced cut-off wheels [insert link] to make an angle grinder in miniature, but it can also be used to drill, sand, or otherwise shape objects into anything you desire. Dremel’s are nearly indestructible workhorses and make for a worthy addition to your tool chest.

10. Linesman Pliers

BHM Lineman’s Pliers

A quality set of pliers is a must for any handyman, including automotive enthusiasts. They are used to pull, twist, and cut wires. Lineman use these for heavy electrical work, but these pliers are remarkably well suited for automotive and household work. Whether you use them to wire up sagging exhaust on your beater or to cut new lengths of wire to length, you are sure to find a use for a quality pair of Lineman’s Pliers.

Raceland “shorty” headers vs eBay longtube headers for an e30 BMW 24v swap

Posted on June 17, 2013 by RJ

Another problem I inherited with my ’91 318i e30 is that exhaust wasn’t finished when the M50 was swapped in. The previous owner purchased Raceland “shorty” headers intended for an e36 325i, 328i, or M3 but the recommend headers for this swap are the longtube SuperSprint header clones commonly available on eBay. Neither set of headers is what I would call a direct fit, but the longtubes are much closer to fitting correctly. Because the Raceland shorties want to violate the control arm bushings, I decided to buy a new set of eBay longtubes for the grand total of $110 shipped to my door from the seller “SpeedDaddy”; below is a quick comparison.

First, the eBay headers I purchased have “1.75” outlets / collectors according to the auction listing. There is another version that has “2.00” inch outlets and costs a little extra. I measured 2″ on one collector and 1.75″ on the other where it necks down. My plans involve welding on a V-band so that 1.75″ section will get cut off anyway!

e36 Raceland headers mounted on an M50 in an e30 engine bay

The Racelands fit on the car but clearly will not clear the lower control arm bushings. The treehouse racing “eyeball” control arm lollipops/bushings might clear, but they’re bloody expensive and I’m afraid they might ride harshly.

e36 Raceland header e30 clearance issues close-up

And one from the bottom

Raceland header e30 fitment from the bottom

It’s hard to tell what’s going on in that picture because things are so crowded, but hopefully it gives some idea about how the Racelands fit. I was going to modify them to fit, but I thought it would be easier just to buy another set of eBay headers. So here they are!

“SpeedDaddy” e36 longtube headers

As mentioned above, you can see that the end of the righthand header necks down. At the end, the header on the right measures 1.75″ in diameter whereas the lefthand header measures a 2″ diameter. Odd. Other than that, they certainly look nice.

Racelands on top, longtubes on the bottom

Here are both sets of headers next to each other. I think these pictures speak for themselves – the Racelands are clearly better quality. Another telling sign is that the longtubes are the lighter set of headers, despite appearing much larger; the stainless steel used in the longtubes is much thinner!

Longtubes on top, Racelands at bottom

And here’s a different angle. Note the O2 sensor placement differs.

Racelands on top, long tubes on bottom

Speaking of quality, look at how much thicker the Raceland flanges are! That and I’m pretty sure the eBay header flanges are not flat.

Longtubes in the engine bay

After a very long fight, I finally fit the longtubes to the M50. Where the racelands pop on and off quite painlessly, the longtubes require some serious fiddling to squeeze into place – from the bottom. The one header also needed some “adjustment” with a hammer to clear the passenger side floor. However, that process wasn’t too bad and the O2 sensor DID mount into place although it is a tight fit.

Longtube fitment from the bottom

Finally, here’s the proof that the longtubes do indeed fit. Next up, V-bands and header back exhaust!

Fitting an ATE Porsche 944 Brake Booster to an E30 BMW Part II

Posted on June 14, 2013 by RJ

My ’91 BMW 318i e30 arrived with a partially completed 24 valve M50 swap. One of the problems with the 24 valve motors is that the intake manifold does not clear the factory brake booster which leaves about three common options:

(Re)Drill or slot the firewall to move the factory brake booster over about 3/4″. This is not recommended as the linkage can bind.
Fit an e30 325iX or e32 735i “double” brake booster (they’re basically the same) and use the appropriate master cylinder. This option is supposed to provide additional brake assist and the booster does not need to be modified. However, the booster is a good deal deeper which requires that the brake lines be bent to fit and it requires that a remote mount fluid reservoir be used so that the master cylinder will clear the throttle body.
Fit a Porsche 944 brake booster and use the factory master cylinder. Of course, the booster needs to be modified to fit the e30 and the degree of modification varies depending on if the booster was made by Girling or ATE. I already covered the Girling booster here.

The previous owner of the ’91 opted for option two, and indeed an e32 brake booster & master cylinder were mounted in the engine bay. I did not like this setup to begin with as the booster rubbed against my throttle cable & caused it to bind. Additionally, the master cylinder sat so close to the throttle body that it made it hard to work on the engine and the remote reservoir give the engine bay a clean, factory appearance in my opinion. The straw (or two ton weight as it were) that broke the camel’s back came when I fired the engine up; I had a massive vacuum leak that turned out to be the brake booster itself. Rather than replace the e32 booster with another e32 booster, I opted to buy a factory ’91 318i master cylinder and reservoir, and a “low miles” 944 booster.

Rusty ATE Porsche 944 Brake Booster

I was in a time crunch so I purchased this booster on an enthusiast forum rather than pull
it myself. The seller did not post pictures, but informed me that the booster held a good vacuum and actually came out of a 944 with “85k miles.” Sound good! Imagine my surprise when this rusty thing showed up, complete with a missing stud.

No matter, I’ll clean it up. First step – remove the barely attached sticker and protect the inside of the booster from debris. Next step – wire brush, then sand, all the loose rust off!

Prepped Porsche 944 booster

Then add a couple coats of primer. This is just cheap 97 cents-a-can primer from walmart.

944 booster wearing a fresh coat of primer

Follow up with real paint. I used Rust-Oleum Satin Enamels Black that is supposed to help prevent rust. Truthfully, I used what was around the house but I’m very impressed with how the paint turned out!

Second coat of black paint, still wet!

And here’s the finished product. I think it came out great! And I was even in a rush – it was getting late and rain was coming in the next day, meaning that this booster was slated to be installed before I’d have another chance to paint.

Final paint on the 944 booster

Now that the booster looked respectable, some more work had to be done before fitting it to the e30. On the ATE, the modifications are simple – extend the 10×1.5mm threads (using a die like this) and chop off the excess rod so that it matches the factory e30 booster. Also remove that bowl Porsche bolts on their boosters – it’s not needed on the e30.

Here’s the factory threads on the ATE booster. Note that the rod is smaller in diameter than the Girling version.

Factory ATE 944 booster threads

The threads need to be extended to near the boot.

Threading on the die

I use a Craftsman die that requires a tap & die to use. If you already have the handle, you can save money buy buying this 10×1.5mm die instead. Make sure to use some sort of lubricant, like automatic transmission fluid (ATF), and run the die down the threads.

Threading the 944 booster

I use Vise Grips with the end in a vise to the hold the booster’s rod in place. You do not want to turn the rod on the booster a lot as it can rip the internal diaphragm and destroy the booster. After you are done threading, measure the factory e30 booster rod, transfer the measurement to the 944 booster rod, and cut the rod to length using a hacksaw or angle grinder. You are now ready to transfer over the e30 clevis & install the booster!

Installed 944 booster!

And there’s my installed 944 booster. Finally, I leave you with a shot of all three boosters.

e30, e32, and 944 boosters

From left to right – factory 1985 325e brake booster, e32 735i brake “double” brake booster, and the Porsche 944 ATE brake booster.

RJ Nunnally

Cars, Computers, and Coffee

Monthly Archives: June 2013

How-to Rebuild Fuel Injectors

BMW M50 Power Steering Delete Belt

10 Useful Tools Every Mechanic Should Own

Raceland “shorty” headers vs eBay longtube headers for an e30 BMW 24v swap

Fitting an ATE Porsche 944 Brake Booster to an E30 BMW Part II