Hard starting after injector change

[dburress]

Here is my problem. I have a 2002 7.3 F250 with 150K miles. I have a superchip tune on performance, K and N air intake, turbo back 4" exhaust, 35" tires, 4.56 gears and a 4" lift.

I had/have a "tap tap tap" noise in the engine that runs good. No miss, no smoke (except black when you punch it). One guys said bad piston, one guy says fuel/injector knock. I take it to Ford and have a buzz and contribution test done. They tell me #3 injector is bad ($239 for that info). I order a re-manufactured stock injector and replace the #3 injector along with the gasket and UVC harness and MAP Sensor. Swap out seemed to go very well. No problems.

Now it will not start via the auto start (did before perfectly) and needs to be turned over for 3 or 4 seconds before starting. Now it has a constant plume of gray smoke that comes out as I drive and the freaking tapping is just as bad.

So good advice here would be greatly appreciated. These motors are supposed to be bullet proof.....

 

[rammertide07]

I'd lose the k&n first....are you pulling any codes with a scanner? And did they re-check the injectors after they installed that one?

 

[DaveBen]

Gray or Blue smoke is oil. I hope they replaced everything (injectors) properly. The injectors use high pressure oil to power the injectors, instead of a spring. In general, these motors are bullet proof.

Dave

 

[JRJ04]

my guess is an o-ring was pinched/improperly installed and thats causing oil to get by...it would explain your smoke and hard starting.

 

[BIG JOE]

What JR sez, but Gray smoke can also mean.. un-burnt fuel. Maybe the Re-man injector isn't right ??

 

[JLDickmon]

I saw this discussed on another site.. but good enough information to bring up here..

Auto Enginuity software is like $400.
I saw ACER laptop computers advertised somewhere for $300.

So for 1/10th the price of my Snap-On MODIS, you can have a pro-grade scan tool

which you need if you're going to DIY much on these trucks..

back to the OP
sounds to me like either
A. "new" reman injector is bad
B. like Jourdan said, it's got a bum O-ring
C. it's got air trapped in the high pressure oil system in the head.

usually when you replace injectors in a 7.3, you take it out and, drive it like you stole it for a hour or so, to purge the air from the HP oil system

 

[dburress]

Well the smoke has all but disappeared after driving it for a few days. BUT we have been babying it to the max (not knowing the problem)..The hard starting has almost gone away although it still isn't 100% back to the ease of starting prior to changing the injector.

No miss in the motor, black smoke when I punch it hard but no more blue smoke.

How would I get air out of the head/injector/HPOP or whatever else it may be trapped in? What is this tap tap tap I still have. "seems" louder since the change out as well. But could be just me more tuned into listening for it now too.

Thanks for all your suggestions. I am 99.9% sure I didn't pinch an o ring or install it wrong....the old one came out with a lot of black on the portion of the injector above the fuel port and below the oil ports...

 

[JRJ04]

well i cant speak for the tapping you hear, but as for the oil...

drive the HELL out of it. thats what will purge the air from the system and get everything cleaned out. should completely eliminate your hard starts, and smoke in the exhaust...except for the black which is normal

on edit...a lot of guys will go and take it and turn the OD off and cruise down the freeway at 70mph...running around 2500+ rpms...thatll help clear it out.

 

[BJS]

drive the HELL out of it. thats what will purge the air from the system and get everything cleaned out. should completely eliminate your hard starts, and smoke in the exhaust...except for the black which is normal

it takes time and running the truck to get the air out of the High pressure oil system, hard starts are normal for the next 500ish miles.

 

[Dogman]

dburress. There is a place at 6515 Adamo Dr. Southeast Power Systems here is there site Diesel Plus
Get a bottle of Stanadyne they sell it there, and try a small one this should fix the tapping. This new fuel we are having to run now does not have the lube in to keep are motor quit now. So with a new injector you don't have the crap on it so it's going to make more noise then the others. I have a new motor in my truck and the tapping is driving me nuts, the Stanadyne made a hugh difference in the noise.