[FORDsuperduty]

Ok so I have a little issue on my truck I've had for a year. weather its cold or hot out the truck starts right up but has a noticeable miss at idle and trucks shakes a good bit but not super bad there's no smoke or lack of power. I have done new ZD11 glow plugs Ford harnesses I did notice the #8 injector was an AD and not a AE. I have a new CPS ICP sensors. Zero blow by and perfect compression! I have the auto ingenuity program and ran the cylinder rational velocity test when cold and warmed up here's what I got.

#1 these are warm numbers
1.4% here's the thing I did a cold BUZZ test after sitting 3 days and injectors 1,2,3,4,5,7,8 buzzed weak and 6 was nice and healthy
#2 sound like its time for injectors????? my truck has 354K miles but don't know if they have been done or not.
0.0% I just did 4 full 7.3 injector replacements this week at work so if I have to pull them I will.
#3 truck even fires up is 2 seconds in 20 degree weather on first cycle of glow plugs
1.9%
#5
0.0
#6
0.0%
#7
0.0%
#8
7.1%

 

[klhansen]

Your '99 would have had AD injectors in all cylinders from the factory. An AE injector would have been a fix only if the owner complained of cackle. The AE started being used in 2000 from the factory.

Do you have the grey recall CPS in it? If so, it can cause a Cylinder Contribution Test failure on #8 and frequently #3 as well. Not a cause for concern, but if you have a miss, it may well be time for injectors with 345k miles.

 

[FORDsuperduty]

Ok I was lucky enough to get a hold of 3 original black CPS a few years back I swapped in another one and still does the same thing so I put the old one back in. my fuel pressure is right at 70psi idle and WOT drops to 64psi so it's right on filter changed every 30k miles and all stock besides a GT38R and exhaust. I pulled the EBP sensor and the tube was about 90% clogged but still had correct readings. I've got it down to 3 hours to pull injectors and reseal them and drop back in to check. 2000 plus on a set of injectors is impossible just after Christmas and tax time lol so I'll pull them reseal them and check the clearance on the armature maybe shim them back to spec for now.

 

[FORDsuperduty]

So with the #8 injector being over 7% I'd suspect that one being really bad shape then. I have the black CPS

 

[FORDsuperduty]

i replaced #8 injector with a good used one from work and seems to have taken care of 90% of the idle issue. the armature was only .0015 on number 8 injector

 

[Davismx]

Would truck have a rough idle randomly or consistent? I'm having a similar issue