Hello folks, I've been lurking the site for many years and used a lot of suggestions for the forum for repairs on my trucks. I now have a problem I would like specific help with. I have a L99 dually 4x4 auto trans that on my last trip was lacking power towing my 10000lbs travel trailer up hills. The truck has 165000 miles on it and was all original. When I got it home I hooked up my AE tester and it had no codes. I buzz tested and had a lot of muffled injectors. Figured with that mileage it is due for injectors. So, as I had a big job ahead of me I went wild with the wallet and got on Riff Raffs website and purchased stage 1.5 180cc full force injectors, Edge revolver tuner, HPX, FRX, high flow CVD, high flow banjo bolts and a new EBP sensor as the old one showed 18psi with koeo. I got Victor Reinz valve cover gaskets from Rock Auto. I got all the parts installed following instructions and threads on this site. After a hard start it idles rough, as expected. I took it for a long drive but only got 4 miles before a SES light popped up and it started to run very poorly shuddering like a loose front wheel at about 1500 rpm. Nursed it home, hooked up the AE and got the following codes: P1316 IDM, P0605 PCM, P0269 #3 contribution and P0284 # 8 contribution. I ran all the tests and # 3 and 8 cylinders vary between 3 - 5% on the balance test. This is actually better than before the new injectors. I have the gray CPS and I have read on some threads this may be normal. I did a compression test when I was installing the injectors and got between 320 and 360 in all cylinders with #8 being the best. I buzzed all injectors and they sound crisp and loud. What has me stumped is that I checked for resistance at the 42 pin plug and got between 4.5 and 5.6 ohms in all injectors except #5 that got 26 ohms. I pulled the passenger side valve cover plug and tested the pins. This time #5 showed an open circuit. If #5 is the problem circuit why does it not show as a code and why are #3 & 8 showing up. Before I dig into the valve covers again I want some advise from the experts on this forum. Could my problem be from the Edge tuner? I scrubbed the PCM board pretty good and was starting to show copper on a couple of terminals. Could it have fried my PCM? Would that bad resistance cause the P1316 code? I am pretty new to AE, how do I pull codes from the IDM or does the 99 not store them? Also my GEM, ABS and Air bags do not show up when pulling codes on enhanced drivetrain. Could I pull the tuner and run the truck for a short period to see if that isolates the tuner? Any Ideas or help would be appreciated. Sorry for the long post!

 

A side effect to doing a lot of improvements at the same time is the problem that you have, Keith. As in which improvement is the problem.

I would pull the tuner and see what happens. Non stock injectors usually need the tuner to run properly, but since you installed both at the same time, it is hard to know if the tuner is working ok.

Did you buy new injectors? If they buzz good that means that you have a good electrical connection from the IDM and the solenoids are functional. If they are used injectors, you have no assurance that the fuel and high pressure oil functions are working ok.

Could you have some wires( like grounds) not connected? I would check all of your more obvious ground connections for corrosion or looseness.

The other point I want to stress---you had a problem before you did all this work that you did not troubleshoot or fix before doing all this work. So I think it would be wise to check all the possibilities for this problem before assuming that any of your work has cause the low power. Go to Tugly's signature line and click on the troubleshooting for a source of advice.

Larry

 

I appreciate the long post, more detail and a sense of the progression of things help us armchair diagnostics techs get the big picture.

Lack of power with no codes sounds like lack of fuel. Usually from clogged fuel strainers in the tank. A fuel pressure gauge at WOT would verify, but you could try to clear the clogged screens but pulling the hose from inlet of fuel pump (see pic) and blowing shop air back thru to the tank. Remove fuel cap first. That should blow the crap off the strainers for a while. Hutch and Harpoon mods will fix that for the long term.

How does the fuel filter look?

Clear the codes and see what come back.

That big resistance on #5 is a head scratcher.

3 and 8 usually show bad on PERDELS test, no worries. P1316 is often caused by burnt pins on UVCH and similar electrical inefficiences, but a strong buzz test is a great sign that the electrical side is operating, so count yourself ahead. Still, check the underside of the big harness on the driver side where it can rub and short on the valve cover.

 

I don't see where you have checked your fuel tank strainers of checked fuel pressure. You won't regret cutting the fuel tank vent off. Fuel pressure check is tough without the fuel bowl fittings. I would make sure you don't have any wires chaffing (usually by the drivers side engine lift bracket). You may also consider upgrading the HPOP. IIRC the edge tuner leaves a lot to be desired, but I could be wrong.

 

Thanks so far for the replies, retiredsparky, I agree doing many changes at once can make it difficult to track down issues and I had thought of that prior to the work. The thought of having to put all the parts back together and then take them off for access again was more than I could bear! As for trouble shooting I did not detail all the steps I took in my post as it was already going to be a long one. I had ruled out fueling and HPOP issues and all sensors checked out except for the EBP. This left me with bad injectors or compression issues. I had no blow by and I wasn't able to check compression until I had it all opened up for the injector replacement.

 

aawlberninf350 and Kamstutz, I did the hutch and harpoon mods about a year ago after the power issue first arose. I had read about air in the fuel causing this issue. I did hear a bubbling sucking sound at the fuel pump connector that stopped if I pushed on the fuel line. This went away after the mods. I put a 100 micron inline fuel filter and replaced all fuel lines to the pump. I did install a port to check fuel pressure on the filter bowl and and that is at 62 at idle. Have not checked at WOT since the injector install. After my first post I went back under the hood and checked #5 at the 42 pin connector. Now it shows an open circuit, did the buzz test again and #5 was muffled and I got a P1275 high to low side open. How does the injector even buzz when it has an open circuit. I'm thinking I have to check the UVCH and resistance through the valve cover gasket. Guess I should have replaced the UVCH but this being my first time I thought that was all part of the gasket until I got them and I didn't want to wait to order new ones. Idiot!

 

Retiredsparky, They are reman injectors from Full Force, they are supposedly flow tested and matched and I would tend to believe they are good as they would not still be in business if they had a bad product. That said, anything is possible! I will check grounds and there is no chaffing on the wire harness that I can see.

 

During the Buzz test all injectors are powered ON and all buzz slightly (muffled). Only the injector being tested at the time will produce the louder sound (higher voltage). From my understanding the PCM-IDM does this to protect itself during the test. Sounds like your on the right track checking the UVCH and visually is also recommended

 

Got the valve cover gasket off and found oil on the #5 pin. looked like it was burned at first but the oil wiped off. Cleaned all contacts with electrical contact cleaner, reassembled valve cover gasket and UVCH. Bench tested all contacts with less than 3 ohms. Reinstalled on truck, connected injectors and now all 4 show open circuits! Gremlins working hard in this truck. Bit the bullet and ordered OEM gaskets and UVCH's. Will go from there!