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I am wanting to know what to do next to the 97 f350 that i am working on I have been testing for days and can't get a signal to the ipr ground wire yellow/red and can pulse ground to it and make it run and get all good readings for sensors. but it is a no start otherwise.Have changed idm,pcm,cam sensor icp cleaned ipr, tested all wires to and from pcm and idm all pass,and grounds but don't know and can't find what triggers pulse on pin 83 of pcm? Automotive tech for 34 years and have equipment if someone could help me that would be great. Thanks PS don't get many of these in to work on.
The icp volts sits at .24 and ipr pressure is 198 and won't start and if i ground the ipr the icp climbs to 5-7 volts and the pressure to 3000 and the truck starts .The ipr ground curciut has ground with key of and goes open when i turn key on could it be ignition switch?
That is kinda what i thought but wont start with icp unhooked and reads pressure when i make it run but maybe needs to give signal to pcm to turn on ground on ipr passes every test i can find on the net.
little more history about truck it is our fire truck for grass fires and i have been fire chief for 20 years and on dept for 30 and i have to get it running but every part i order takes 3-4 days to get and no trucks like this left around here to get parts from. It ran good when we parked it couple month back and now just won't start 155k km on it and stored inside since we got it used so in good shape. Last year it would shut down every time we keyed the vhf radio and found antenna wire shorted on roof but still would shut down if you use handheld radio near engine. When i built it as a fire truck i wired all fire part separate on a solenoid so shouldn't be affecting anything. Everything is stock. So hopefully someone out there has run into this problem would really appreciate some help. As i have tested and found bad parts i have changed them with still no start but seems maybe bad spike in power to have so many parts gone bad.Also sent in alt and had tested. Icp has 110km but is aftermarket .Thanks
So do you have a way to monitor dc and pressure while cranking? It sounds like ipr/hpop/inj orings not holding pressure until you artificially make the ipr go full duty cycle.
with a manual gauge it has 198-200 cranking and no ground signal to ipr and when i ground it just for a second it spikes to over 3000 instantly,just slowly tapping ground it will hold pressure and run so i thought maybe mechanical parts would be ok, pcm won't default to 725 psi like it is supposed to even if you unhook the icp.
ya to much testing the battery's went dead in my lab scope so i will have to run to town and get some new ones and get some more numbers for you guys maybe help more.
I am not thinking you will be able to see the pulsing with a meter honestly.
X2, the pulsing is too fast for a regular DVOM. You'd need an oscilloscope to see the pulses. Try plugging off the HPO from one head and crank it over. See what the ICP does. Repeat for the other head. I think you'll find a leak in one or the other as suggested.
Thanks that was some of the first testing i had done and installed a mechanical gauge in each side and deadheaded it and only got 198-200 then removed cleaned and installed ipr and still low then tested circuit and found no ground pulse ,added ground and spikes gauge instantly past 3000 psi should put on my 10000 psi gauge but didn't think it was needed. can't get my oscilloscope working even with new batterys so going to use my scanner to test wave form shortly.I will let you know.
hooked up scanner snap-on modis and tested outputs and inputs again and getting flat line on icp output and code 1283 so got anouther new icp coming and try that but it says should start with it unplugged so think i still have problems.Thanks