upgraded injectors for early qs?

[Fridge]

My Q is idling badly again. I had the injectors redone by dershwerks 3k miles ago. I suspect the crappy gas is getting to them. Has anyone found a way to install newer injectors in these cars? This really seems like the weak link. Otherwise the car is great once your rolling it does not miss a beat.

[Q451990]

You might search for a post by "Texas Oil" from earlier this year. He installed the newer design from a 94-96 successfully. I'm not sure if that design is more robust and able to hold up to ethenol, but maybe...

Heath

[Q451990]

What the heck... I did the search for you - wanted to read it again

zerothread?id=214756

zerothread?id=189875

[maxnix]

The main thing to consider is that besides a different valve design, the spray pattern was different for the earlier siamesed and later oval intakes.

Perhaps Keith will report back on how the conversion is working? Probably no difference the first 10K, 20K, 30K?
Modified by maxnix at 11:50 PM 9/13/2007

[Fridge]

OMG I did not realize it was that bad. If I pull the plenum again I will try to put the newer injectors in it. Does anyone know if the 96 injectors are lasting? I would hate to do all that work for nothing.

[Q45tech]

Changing the spray pattern or the ramp up time to fully open may mean rewriting idle software in ecu [???].

The trick is new injectors for longevity, not some already exposed but still functioning used units.

[Q45denver]

Is it possible that the manufacturer may have improved the plastic compositions in the replacement injectors over the years since it should have been a known manufacturing defect by now?

Texasoil indicated he installed the 96 injectors in his 92 using steel washers in the intake manifolds.

zerothread?id=214756

Quote "Actually, deleted the OEM hard black spacers under fuel rail bolt pads, shimmed to(lower) level height with steel washers so all square up with injectors fully seated. Injector tip sits +/- 1'8" deeper into intake runner."

The 96 version are the top feed style I understand, and may be similar to the 97-01 versions? I haven't heard of any problems with the '97-01 injectors. However, wouldn't you need to use some kind of rubber gasket to install the fuel rail into the intake manifold in order to get a tight enough seal around the individual injectors?

[texasoil]

The later injectors are working great--the engine is smoother than ever before, 500rpm idle is silky smooth now, not a ripple at any speed. MPG is up over 5% from previous many trip to/from Morgan City (330 miles each way). Emissions (state testing) are down substantially (always on fresh oil change, 20 min preheat on freeway,) Are WAY WAY below limits now,

[96Qowner]

Keith, are you running ethanol through these injectors? Could they be a solution to ethanol-contaminated gas in the Q45?

[Q45tech]

"Emissions increased on all 10 vehicle fuel systems studied when ethanol replaced the MTBE inthe test gasolines. The average permeation emissions with a 5.7 volume % ethanol gasolinewere 1.40 grams/day higher than permeation emissions with the MTBE gasoline and 1.10grams/day higher than permeation emissions with a non-oxygenated gasoline. This isequivalent to an average permeation emissions increase of 65% with a change from the MTBEgasoline to the ethanol gasoline and 45% with a change from the non-oxygenated gasoline tothe ethanol gasoline. The average permeation difference between the MTBE fuel and the nonE65Final Report - Fuel Permeation from Automotive Systems2oxygenate fuel was 0.30 grams/day. The differences between the ethanol fuel and the othersare statistically significant at the 95% confidence level. The differences between the MTBE andthe non-oxygenated fuel are not statistically significant. The results of this study apply to 5.7%ethanol blended gasoline as used in California, but may not necessarily apply to higherconcentration ethanol blends or different gasoline compositions. This report with detailedresults of the test program has been posted on the CRC’s web-site at http://www.crcao.com and onCARB’s web-site at http://www.arb.ca.gov/fuels/gasoline/gasoline.htm."

http://www.crcao.com/reports/r...4.pdf

Top 46 chemicals in 3 samples of gasoline

Liquid Fuel Speciation Comparison – Top 46 ComponentsFuel A Hydrocarbon Species Sorted by Weight % in the LiquidFuels B and C Components Aligned with Fuel AFuel A Fuel B Fuel CSpecies Wt.% Wt.% Wt.%OxygenatesMTBE 10.50 0.00 0.00TAME 1.12 0.00 0.00Ethanol 0.00 5.86 0.00Hydrocarbon SpeciesToluene 9.61 8.06 9.982-methylbutane 9.07 6.64 10.862-methylpentane 4.42 5.21 6.98m-Xylene 3.72 4.69 5.633-methylpentane 2.73 3.36 4.22Pentane 2.69 2.23 3.84Methylcyclopentane 2.54 2.84 3.39124-TriMe-benzene 2.38 2.58 2.42Hexane 2.00 1.66 2.59o-Xylene 1.76 2.13 2.60224-triMe-pentane 1.63 3.64 2.193-methylhexane 1.59 2.81 2.12Methylcyclohexane 1.52 3.16 0.901-Me-3-Et-benzene 1.49 1.65 1.522-methylhexane 1.46 2.51 1.792,3-dimethylbutane 1.29 1.40 2.032,3-dimethylpentane 1.18 1.75 1.51Ethylbenzene 1.18 1.42 1.84Heptane 1.17 2.90 1.20Cyclohexane 1.15 1.12 1.91p-Xylene 1.14 1.45 1.532-Methylheptane 0.91 0.70 0.663-methylheptane 0.86 0.76 0.762,2-dimethylbutane 0.80 1.07 1.47233-triMe-pentane 0.79 1.30 1.17234-triMe-pentane 0.77 1.38 1.02135-triMe-benzene 0.74 0.86 0.76Butane 0.67 0.72 0.68Octane 0.66 0.45 0.37Benzene 0.64 0.86 0.851-Me-4-Et-benzene 0.61 0.73 0.661C3-diMecyclopentane 0.58 0.90 0.392,4-dimethylpentane 0.56 0.67 0.69225-trimethylhexane 0.53 0.36 0.951-Me-2-Et-benzene 0.52 0.53 0.51Propylbenzene 0.51 0.45 0.431T3-diMecyclopentane 0.50 0.78 0.33123-triMe-benzene 0.48 0.48 0.482-methyl-2-butene 0.48 0.54 0.471T2-diMecyclopentane 0.46 0.83 0.26Cyclopentane 0.46 0.40 0.542-Me-3-Et-pentane 0.42 0.52 0.452,4-dimethylhexane 0.41 0.59 0.442,5-dimethylhexane 0.38 0.50 0.40% of Fuel 81.1 85.5 85.8The 5.86 weight percent concentration of ethanol corresponds to 2.0 weight percent oxygen in

[Q45denver]

Recent news story on local TV channel indicated that recent study by local university indicates that ethanol increases ozone (particularly in summer) and other pollutants significantly over non oxygenated fuels.

[Fridge]

Ohmed out the injectors. Found #5 with 50+ ohms so that must be the culprit. This is such a pain but the fix does not seem that difficult. I have a old motor laying around so I can mock it up. The part I am worried about is spacing the injector to get the correct height. It seems that it would cause a vacuum leak to stack the flat washers under the injector body.

[maxnix]

Well, you could use rtv and press them together. Or precision trim an OEM rubber one.

I would be concerned about the dampening effect lost by not using the OEM rubber one. Probably done for sound attenuation during injector valve operation.
Modified by maxnix at 11:00 AM 9/17/2007

[Q45tech]

The use of the word upgrade in the tread title is a misnomer since no later injector fits without some modification and system redesign!

The rubber fuel hoses need to be improved if ethanol is in their diet.

[Fridge]

I called Deatschwerks this morning and they are making a kit to put the phase2 injectors in the older cars. It comes with a adapter to fit the new injector to the rail and a terminal kit to adapt the harness. He says that while the newer injectors flow more fuel the stock ecu seems to be able to compensate.I ordered the kit for 618. shipped. While I am at it I am replacing the dead knock sensors. I am already getting stoked

[Q451990]

I called Deatschwerks this morning and they are making a kit to put the phase2 injectors in the older cars. It comes with a adapter to fit the new injector to the rail and a terminal kit to adapt the harness. He says that while the newer injectors flow more fuel the stock ecu seems to be able to compensate.I ordered the kit for 618. shipped. While I am at it I am replacing the dead knock sensors. I am already getting stoked

Very interesting! Please take some pictures of the kit and post them so that we'll know what's available.

Thanks!

Heath

[Q45denver]

It will be interesting to see what they send you. I planned to install some Series II injectors in my 1990. I have a set recently serviced by Deatschwerks ready to bolt in but was hoping to sell a set of new OEM '90-93 injectors I have listed in the classifieds before the market for these dries up. I have verified that the 1994 injector harness plugs directly into the engine harness with no adapter needed. Also it appears that the 1994 injectors can be installed in the 1990 intake manifolds using modified 1994 OEM hard black spacers together with the OEM 1990 spacers. I do not know if the difference in depth that the 1994 injectors extend into intake runners would be significant but they probably should be shimmed out using steel washers as Keith suggested.

[Q45denver]

Unbelievable!

I just tried starting my 1990. It has been sitting undriven for a couple months. Two injectors were ohm testing marginal last time started and had rough idle. Barely started and won't rev over 2000 RPM . Most of the injectors are totally dead and only a couple even have an Ohm reading.

A**hole mechanic didn't install new injectors like I asked. I guess this gives me the opportunity to do it right by installing the set of '94's I have. Or should I use 1996 ones? This car has been having injector issues since new. Crappy Colorado gas!!

[Fridge]

Well I got started today. The kit comes with some spacers to make the lower part of the injector body fit the old fuel rail. The newer injectors have a smaller diameter and I dont think that they will fit with the spacer. A well thought out kit I hope it works as well as it looks.I took some pictures now if I can figure out how to post them...

[texasoil]

it seem there are seceral 'versions' of fuel injectors on ther G-50 engines. 90-late 93 were all the same--wire spring clip on electrical connector. 94-95 were different-, tan body, still side feed as earlier, different electrical connector-

late 95-early 96?, pink/light purple body, shallower fuel rail so gotta make the 8 black plastic hold down bolt spacers thinner to get injectors to seal on manifold runners- same elecrical as 94-96.

Late 96 have TOP FEED 'pintle-less injectors-totally different need the rails and wiring harnesses.Wife's 92a with '96 used injectors is slightly grainy at idle now-not velvety smooth as it was. Gotta run some good cleaner through it I hope. We use Chevron almost exclusively

[Q45tech]

Use a digital oscilloscope to measure the injector offset....the ramp time vs current and the ~ point in the current which shows opening point.

I'm sure the is a few usec [probably 0.1 millisec] difference due to mass changes in the assembly.

Remember at idle the open time [1.1millisec] is less than the full flow time [1.5 millisecs]....the injector voltage is shut off BEFORE the injector fully opens....................same prolem at 55 mph except the O2 can trim which doesn't occur at idle.

Probably idle uses 0.1 millisec steps vs cruise which can trim to +- 0.02 millisec steps.

Rest the idle learn by discoing IAC per FSM.

[Q45tech]

Something to try a 94 ecu which might deal with 94 injectors a bit better at idle.

[Fridge]

Well I finaly got it done. I was away at a expo for a week. Set the timing and idle. Man so this is what a Q is supposed to run like. Purrs like a kitten totally silent at idle. The knock sensors had been bad for a while and with all the injectors hitting she has a lot of power. Now I just need a Nico ecm.........hint hint

[Q45denver]

Any specifics or pics as to what was replaced?