Cascade Crew

chevymad · Posted: Sat Oct 26, 2013 12:38 pm Post subject: Injector experiment

Jeep tech.. but might apply to tpi cars. My 03 jeep has bosch injectors with the single hole. These squirt a stream of fuel instead of a mist. I've seen some people buy "upgrade" injectors which have 4 holes and do a better job of atomizing. My jeep gets terrible mileage and though that is common I thought it oughta be better. I've allready changed all 4 O2 sensors, tps and gave it a tuneup. I've also cleaned the injectors 2 different times and both times made the jeep run smoother for a few weeks then back to its normal self.

Bought myself a fancy wireless scan tool ($10 ebay!) It's bluetooth and connects to my windows tablet. With it I can read/graph all the pids and check/erase codes. Looking at that I have noticed that my long term fuel trims were both excessive. Bank 1 was 15% and bank 2 was nearly 12%. My new tailpipe has also turned black inside.. and this is after the cats. So I figured there was room for improvement somewhere.

So with all this in mind I figured at the least my injectors were severely dirty and with 160k miles on them now probably fairly worn too. So I ordered a set of the "upgrade" injectors from a place on ebay. They reman them, ultrasonic clean them, flow test and then flow match the set, all with a 1 year warranty.

Installed them this morning and hooked up the scanner. Immediately the fuel trims started coming down. Just took a drive to Cathlamet and back then rechecked. Bank 1 is now at 2% added fuel and bank 2 is subtracting 0.78% !! There's also more off idle torque. Clutch can be released with no throttle whatsoever where before I had to give it some gas and let it buck slightly.

Success! Mileage should improve just by looking at the trim values.

Now the tpi tie in.. Do tpi injectors have the single hole or multiple? And if they're single I wonder how much the newer style injectors could make a difference? I can't even be sure if thats what makes the difference with my jeep. The old injectors were probably just shot since they didn't seem to match the factory tuning.

Twilightoptics · Posted: Sat Oct 26, 2013 12:47 pm Post subject:

Stock TPI injectors are pintle design. Not really one "hole" but more like a common garden hose sprayer with a piece in the middle to cause the spray.

The Ford SVO injectors are 4 hole.

I had my jeep injectors flowed and cleaned after I had a cat blowup. The worst one at 90,000miles was 5% off of what it should have been. They were able to bring them to within 0.2%. My idle smooth out after, but it seems to have gotten a little choppy again, nothing bad though. I can idle out through the clutch with 3.73 and 33" tires.

What scanner did you get? Seems to work okay? Sounds cheap to me, but I'd be willing to try it. I'd be interested to see what mine read.

chevymad · Posted: Sat Oct 26, 2013 1:05 pm Post subject:

It's a chinese ELM327 scanner. Don't use the disc that comes with it though, loaded with a virus. I've been evaluating software and think I'm going to go with Touchscan. That's about $30. This is the scanner I'm using. It will also work with android phones with apps like Torque. It will not work with iphone because apple doesnt use a complete version of bluetooth. Unless you jailbreak anyway.

http://www.ebay.com/itm/Mini-ELM327-Bluetooth-V1-5-OBD2-OBDII-Auto-Diagnostic-Scanner-Adapter-Tool-/161135775336?pt=LH_DefaultDomain_0&hash=item258470ce68

Here's a vid showing the difference in injector pattern. Midway through is the best part of the video/propaganda. https://www.youtube.com/watch?feature=player_embedded&v=g073Fwvq240

chevymad · Posted: Sat Oct 26, 2013 1:10 pm Post subject:

Oh and you can even use the scanner with your phone/tablet/laptop and create a dashboard showing gauges for any pid your vehicle has in its ecm.

aaron_sK · Posted: Sat Oct 26, 2013 3:37 pm Post subject:

You damn kids and your OBD2, with it's easy, universal scanning! #$%^&*

Nice to know that China is sending CD's full of viruses over here for mechanics to install. Laughing

I ran into the same issue on the BMW. From the factory they had old single-pintle Bosch injectors. I upgraded to Bosch four-pintle units with the same lb. rating off of a Ford. No change in fuel economy or power but much better idle and tip in.

Twilightoptics · Posted: Sat Oct 26, 2013 4:18 pm Post subject:

Fords lb rating is usually at a lower psi too.

aaron_sK · Posted: Sat Oct 26, 2013 4:31 pm Post subject:

Yeah, lb. rating means nothing unless you know what PSI it was at. Most of the time they are rated at three bar (or 43 psi) and then they are over or under-driven from there.

chevymad · Posted: Sat Oct 26, 2013 4:40 pm Post subject:

I know most upgrades are ford, but this set I just got clearly have pentastars on them. Wonder what they're from?

aaron_sK · Posted: Sat Oct 26, 2013 4:45 pm Post subject:

Did they have a standard Bosch part number stamped on them?

RSFreak · Posted: Sat Oct 26, 2013 9:32 pm Post subject:

Perhaps that is why the previous owner of my T/A swapped in Ford pink tops! Cool

chevymad · Posted: Sun Oct 27, 2013 5:19 pm Post subject:

Not sure on the part # List of digits but didn't pay attention past that.

Alphius · Posted: Mon Oct 28, 2013 7:58 am Post subject:

Some but not all Ford injectors are rated at 39.5 psi. Others are rated at 43 psi.

chevymad · Posted: Mon Nov 18, 2013 7:37 pm Post subject:

Well, jeep does run much better but no gas mileage gain. In fact its probably worse! LOL Couple tanks have been just over 13mpg, one tank inexplicably calculated to 20?? 200miles and put 10 gallons in. No idea what happened there, and one tank at 15.5 mpg.

fiveoformula · Posted: Mon Nov 18, 2013 10:46 pm Post subject:

Interesting, 16mpg highway is the best I've seen from the old cherokee, when I took it down to Salem once. In town its 12-13mpg consistantly.

Twilightoptics · Posted: Tue Nov 19, 2013 7:14 am Post subject:

17-18 consistently in the 87 cherokee. My wrangler still gets 14city 15.5-16 hwy.

chevymad · Posted: Tue Nov 19, 2013 7:17 am Post subject:

Stock I got just over 20 on the highway and 15-16 just driving around. Tires and lift killed that. I've had as bad as 11. Though in the high elevation around yellowstone and with their low octane but no alcohol fuel I did get a couple tanks at 20 again.

This last tank at 20 was especially odd because most of that was spent wheeling.