Summit injector connectors, no dice :( Options

[yarin]

Excellent points Dave.

My wiring harness is done right, you'll see pics over the next week. The injector connectors, the fitment seems good, its a tight fit. I can't visually confirm the level of electrical connectivity of the mechanical contacts, but i guess that will show up as a problem if it really is a problem. I didn't cut any corners with my install, so far I think I've taken every precaution from redoing the entire fuel system front to back, 14' of 7.5mm fuel injection hose, custom relay box enclosure, rubber mounts for brain and relay box, and more. The install should turn out very clean.

I couldn't find anything on I-Jet. Any links?

[lapuwali]

It's L-Jet, not I-Jet. Bosch L-Jetronic is almost certainly the most commonly seen fuel injection system, since it was used on so many European and Japanese cars from the mid 1970s to the early 1990s.

[Cap'n Krusty]

QUOTE (Jeff Nelson @ Mar 28 2006, 08:05 AM)

I've been looking for some L-jet style injectors, because of the superior electrical connector, for my MS 2L project. I had discounted the 1.8L injectors as having insufficient flow. I may rethink that. Here are a couple of links related to that search: http://www.ratwell.com/technical/Injectors.html http://www.shoptalkforums.com/viewtopic.php?t=98138 Since the 187cc/min injector (aka 1.8 injector) was used on the 912E, which is a performance version of the 2L motor (relative to a bus application), it's probably ok for a mild 2L 914 motor. These are likely high impedance (12-15 ohms) and are easier for the ECU to drive. Anyone got some handy that they would measure the resistance of to verify?

L-jet injectors use a resistance package in the system. D jet doesn't. I think we can safely say they won't work as a direct substitution on that alone, and it's also a reasonable assumption that the ECU won't drive 'em. Jeff Bowlsby has the correct boots, I believe, and the proper connectors as well. This is a case of trying to reinvent the wheel, with the decided disadvantage of not knowing what it does or what it looks like. The Cap'n

[lapuwali]

The L-Jet injectors have a resistance pack because those resistors aren't in the L-jet ECU. They ARE in the D-Jet ECU, however. With Megasquirt (which yarin is using), the need for the resistors (these are low impedance injectors) is handled either with a resistor pack, or by using PWM modulation of the drive voltage.

D-Jet injector connectors suck big rocks. They're loose, and rely on easily split boots to retain them. It's a sucky design, and I see no reason to not improve on it. The L-Jet injector connectors (some of them, anyway) will fit, and actually provide a perfectly good seal. They don't positively lock, but neither to the D-jet injector connectors.

I'd agree that using L-Jet injectors and L-Jet injector connectors would be a better plan, but if you already have D-Jet injectors that are known to work, there's little reason to NOT use them with L-Jet connectors. You're certainly no worse off than you are with stock D-Jet connectors, and may very well be better off. I certainly know of people who've managed to successfully use them for quite some time. Since there are relatively few hose-barb injectors available, and D-jet injectors are readily available to someone converting D-Jet to MS, then using what you have presents a pretty strong argument. You're not re-engineering the entire fuel feed system, for one thing, just the electrical connection. Which is more dangerous, redoing the entire fuel system, or just the electrical connection? Which has a greater chance of serious problems if it fails?

Nothing gets my goat faster than people who insist that the factory is the sole holder of all engineering knowledge, and that no-one else could possibly ever do a better job than the gods at The Factory. Sometimes, the factory fucks up, and IMHO, D-Jet electrical connections are one such place where Bosch dropped the ball.

[DNHunt]

James

I agree with most of what you say. Indeed, the factory is not the end all be all and the greatest potential for catastrophy lies with changes in the fuel delivery system. I agree that the D-jet connectors suck. I may be wrong but I still think that Yarin is going to have a problem with mix and match. I wouldn't do it but that is just me and I really hope he proves me wrong.

Probably the worst thing that will happen if it fails is he drops a cylinder until he figures it out. Not that big of a deal.

Dave

[914werke]

OK so do I understand correctly : that the resitor pak is unnecessary in the D-jet intall because that function is handled buy the ECU and that 1.8 injectors (if you had them or had to replace injectors) would be a better match to a mild/street 2.0-2056 motor ?
Oh and in doing so have the bennifit of the superior mechanical connectors?

[rhodyguy]

ray greenwood over at STF has written pretty exstensively about using the L-Jet connectors on the D-Jet injectors. it sounds as though he's been pretty successfull at it.

k

[914werke]

Nice non answer there slappy (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif)

[rhodyguy]

what would you like me to say there sport coupe? the whole issue to me is the appearent unavailibility of serviceable boots, unless you buy one of jeff's harnesses. i've tried putting a L-Jet connector on a D-Jet injector. it goes on nice and tight and you can still slide the boot on. but are connections inside good? i suppose a mutlimeter and knowing what the resistance should be might be an indicator. i dunno.

k

[lapuwali]

QUOTE (rdauenhauer @ Mar 29 2006, 12:05 PM)

OK so do I understand correctly : that the resitor pak is unnecessary in the D-jet intall because that function is handled buy the ECU and that 1.8 injectors (if you had them or had to replace injectors) would be a better match to a mild/street 2.0-2056 motor ? Oh and in doing so have the bennifit of the superior mechanical connectors?

If you are using Megasquirt or any other PEFI, then using 1.8 L-Jet injectors on a mild 2.0 would work. 187cc/min should be plenty up to 115-120hp. If you're still using D-Jet, stick with the D-Jet injectors, as you can't compensate for the lower flow rate like you can with PEFI. The 1.7 D-Jet injectors flow far more than the 1.8 injectors do, and the 2.0 injectors flow even more, way more than the engine actually requires. However, the D-Jet ECU is set up to operate with these high-flowing injectors by using very short pulsewidths, and it can't be adjusted (for all practical purposes) to use lower-flowing injectors.