warthog

Where do you guys buy your injerctors and do you buy OEM or ford injectors?
Thanks

5-90

First and foremost - love the avatar! The 'Hog is my veridam most favourite airframe (and if I hit the lottery, I'd get my pilot's ticket back, get checked out on one, and buy one of the things!)

The injectors used on the XJ - at least the earlier ones (through the RENIX and OBD-I years) are fairly standard Bosch units, and can be had with a little digging fairly cheaply. Pull them from Ford or Chevvy five-litre small blocks of similar vintage (the Ford 302 and 281 "Modular" V8 or the Chevvy 305ci V8 should all have them. You may also find comparable units in the 330ci Ford Modular/Triton V8 and the Chevvy 323 and 350ci, but they will be rated for higher delivery. I do not recall if the later Dodge LA-Block V8 - 318 and 360ci - used comparable injectors or not. You may need to build a MAP sensor input voltage adjuster to get gross fuel trim down to where the HEGO signal can do the fine work - the response curve of the OEM HEGO sensor is fairly narrow.)

The upper and lower O-ring seats are a fairly standard size, so you're really worried about the flow rate (#/hour at a given supply pressure. The flow rate may be mathematically converted to correspond to a different pressure, but "not all 21#/hr injectors are equal") and the electrical plug (which is a fairly standard Bosch bit as well - in use until at least early OBD-II, I've seen it on vehicles as late as 1999 in general. It's probably used even later.)

This opens up a number of possibilities, so let's highlight a few:

1) Buy new aftermarket "OEM Equivalent" units. Last time I did this, I bought Borg/Warner pieces. I do place a lot of trust in the Borg/Warner brand (I've been using their parts for 25-30 years now,) but I thought they were awfully spendy at $60 a throw - and I needed six (replaced the injectors on a 1987. The RENIX-era pieces are known for leaking at the injector body seam, the crimped join between the metal lower body and the plastic upper. Later pieces - 1991-up - are ultrasonically welded at this point, and there's no crimp to loosen.) So, I paid $360 for a set about ten years ago.

2) There are a couple of "performance aftermarket" outfits that can supply you. RENIX uses primarily GM sensors, so I source my replacements from Marren Fuel Injection (www.injector.com.) Yes, they also carry fuel injectors (you want to find units in the range of 19-21#/hour @ 39psig supply.) You can also source "cleaned and matched pull sets" from FiveO Motorsports (http://www.fiveomotorsport.com) usually for about $200 the set. I haven't priced the pieces from Marren. I have dealt with Marren for the last dozen years or so, and I do endorse their service. I have not had occasion to deal with FiveO Motorsports, but reports from the field are consistently good on them as well.

3) Salvage yard, if you really want to do it on the cheap. Prices will vary, depending on what your yard charges. Go ahead and grab all eight, just in case something goes awry (it's also usually easier to negotiate a lower price if you can demonstrate you've taken an entire set of something, in my experience. Taking "most of" or "part of" a set of parts makes it more difficult.) You will want to get a set of new O-rings for your injectors, but they can be sourced for about ten bucks from the local parts house, or $15-20 from the dealership parts department. However, there is a rule for something you can't get overhauled from the boneyard - caveat emptor ("Let the buyer beware.") I usually won't buy anything from a boneyard unless I'm already planning on tearing it to bits for inspection and overhaul.

NB: If you get them from a salvage yard, flip them over and check the business end under mild magnification. Later Ford and GM injectors were "four-hole" units, which allowed for finer atomisation of fuel. The finer droplets allowed for increased combustion efficiency, which translates to a small (but measurable) increase in fuel economy. FiveO typically calls their units out as the four-hole pieces, and they've been accurate about delivering them (from what I've been told.) Marren can probably supply you with the four-hole pieces as well. OEME and OEMR pieces will be the one-hole type - while perfectly acceptable, you may as well try to get an additional advantage if you can, y'know?

Given a choice, if I had to do the job again (I'm sure I will...) I'll take Option #2 the next time. Costs about half as much as buying aftermarket OEME parts, and you could come out ahead of OEMR anyhow. (I haven't even priced the OEMR injectors - and I'm not sure I want to. If the B/W units were $60 a throw ten years ago, the OEMR ones were probably $100-110 or so...)

GLOSSARY -
OBD-I - OnBoard Diagnostics, generation I. Used in vehicles through 1995, with various incept dates. There was no industry standard for the implementation of OBD-I, as it was spec'd by CARB (and California can't get anything right.)
OBD-II - OnBoard Diagnostics, generation II. Standard in all vehicles, 1996-current production. Standardised system, since SAE took over for this one.
OEME - Original Equipment Manufacture Equivalent. Describes any quality aftermarket part - my favourite brands are Standard Motor Products, Borg/Warner, and ACDelco (in no particular order.)
OEMR - Original Equipment Manufacture Replacement. These are parts from the dealer/manufacturer.
RENIX - The pre-OBD control system used in the XJ and MJ, 1987-1990. Stands for RENault/bendIX - the system was loosely designed and spec'd by Renault (in partnership with AMC,) and built by Bendix/King (the avionics people.)

warthog

Wow thanks for that reply, I will try option two first.

And preciate tha avatar comment, that's what I do for a living (A-10 Crew Chief) aircraft maintenance. Best aircraft in the world

thanks again for your reply

5-90

Oh, brutal! One of my neices is a crew chief for Herky-birds, just finished her second tour in Afghanistan (so there's a bit of kinship there - I did Afghanistan in 1990 and 1993. Saudi in late 1990, and Kuwait/Iraq in 1991...) She'd wanted to enlist for years, and ended up following me into the Air Farce. "Best thing I ever got out of the Air Farce was me," but I'd do it all again (even knowing I'd get as beat up as I have. It was so worth it! I got the opportunity to do things most people would never get to do in my 6/4 service - and got paid for all of it, instead of having to pay to do most of it. Pay's bad and the hours are worse, but some of the opportunities are amazing!)

Yeah, I had a G/A license (Private Pilot and Acro/Taildragger,) but I would absolutely love to zip around in a 'Hog. The idea of doing 200-250 knots below treetop level is attractive to me for some reason - but I've also done barnstorming in a Stearman (when I was flying out of Aretz, we had a CFI who was rated to teach in a Stearman, and he'd take you up for the cost of fuel. Got rated in that thing... Had my Unlimited/Free Fall skydiving ticket already, so sometimes I'd scare him - throw the plane in an Immelmann or a Hammerhead, but unbuckle my harness first and throw myself out of the plane. First time I did it, I didn't tell him I was going to do it - he just saw me go shooting out of the front hole, and I think I heard him yelling from a mile away! Got thrown easily 100' straight up when I crested and nosed over...

(Gawd, I miss flying and skydiving... I wonder if Nanna still has my old Vector that I have Gramps after I blew my knee?)