Replaced injectors, now engine has knock

[bird hunter]

I could use some good advice here. Today I replaced my injectors that were original with 162K on them along with return lines, caps, o-rings. I did not replace the pump yet which is original also with 162K. I do have a replacement U-haul pump I'm just not convinced I can do it myself. So, now that the new injectors and return lines are in the engine starts, but has a small knock and is running a little rough. I assume new injectors (type4) with old pump threw the timing off? The knock can't be heard at idle, but only when the rpms go up a little and I never took it over 1100 rpm because I didn't know if the knock would damage the engine?

I have read Mel's article on IDI fuel pump/injector servicing. I'm just not sure how easy it is to really install and time properly as I guess I don't know what is supposed to be marked and how the pump is aligned or timed?

Thanks for any help as I'm not sure what to do at the moment.

 

[justinray]

Most likely mistimed.

 

[icanfixall]

Its very easy to remove the pump and install it. The help and directions here are outstanding to say the least. The plate on the gear cover needs to come off to acess the three 5/16 bolts on th pump drive to the injection pump gear. The filter to injection pump line needs to be removed for better acess. All 8 hard lines stay on the pump but are removed from the injectors. I know you have done that before so thats easy. The fuel return line on top of the pump must be removed. The throttle and cruise cables needs to be removed to from the pump. That throttle line bracket needs to come off the intake manifold for room too move the pump. The fast idle bracket and solenoid needs to come off the passenger side of the pump. Now the three 9/16 nuts came be removed from the pump housing to the gear cover. The pump must be moved towards the intake to get the top nut off. Crappy ford engineers mistake I guess right there. Once loose move the pump towards the intake and twist it towards the passenger fender. Its slides up thru the two sruds on the passenger side of the cover. Thats about it for removel. While its off change out the tps switch and adapter for the throttle shaft on the bench where its easy to work. Adjusting it later is really easy. If you have a standard trans your not going to have this switch. Have a cell phone handy. Call one of us that can offer you step by step help as your doing the job. Sending pics by phone will help too. Plus taking pics that way will help to reinstall it too. Pics are the best silent helper available. They usually never lie to you...

 

[Ididriver]

For the injection pump.
It really is easy like Gary (icanfixall) said. I was really nervous my first time but it was pro ally one of the easier thngs I've done on my truck. Just make sure not to pull the gear cover off.

 

[bird hunter]

Well after reading icanfixall's post and reading Mel's article a couple more times I think I will attempt to replace the pump. The removal and installation sounds more straightforward now but the aligning up or timing afterwards is what I am not sure about.

So the slight knock my engine now has after injector replacement is just due to being mistimed now? Will driving it in and out of the garage damage anything? Again it doesn't even knock at idle just runs a little rough, the knocking only starts when rpms go over 900 or so.

Thanks for all the help - much appreciated!

 

[Kevin 007]

Driving in and out of the garage shouldn't hurt it the slightest.

 

[Wyreth]

Before you go hog wild and pull the IP, you might want to try bumping it a dimeswidth or two either way. If it's being clattery, especially if it's really noisy on a cold start, try retarding it first. If it's sounds muted, but shutters, try bumping it advance first. Just give it a little ear test, you remember what it sounded like before right?

That's just my two cents worth.


Now, sorry to highjack, but something occurs to me. (especially as I am getting ready to swap out injectors my own self)

Could he have gotten a bit of debris in an injector when changing them? That'd cause a knock, and it could be caused by a bit of dust, couldn't it?
If that happens, is there a remedy other than a new injector?

 

[subway]

if you can loosen on line at a time while the engine is running you can narrow it down to which injector is the troublemaker if you have one. another give away is if one is hotter than the rest by checking them with a IR gun. you can get a bad injector out of the box sometimes.

 

[justinray]

Dimes THICKNESS, not width.

 

[91idi]

My truck knocked after I changed lines. Drove it about 40 miles and wala no more knock. Not sure what causes it put when you change lines on my 91 she sounds like death till a good road trip

 

[Agnem]

A leaky injector is most likely at fault. Timing (especially retarded as it would be) rarely causes MORE noise. You could try running it in hopes that it goes away, but realize that cylinder is going to get hammered for until the knock clears up.