Fuel Injector Raplacement Interval

[guidob222]

Hello - I have a 1982 911 SC with 68,000 miles. I am taking my car in for an oil change, tune up, and valve adjustment. It has been about 15,000 miles since tune up, 10,000 miles since valve adjustment and is time for another oil change. I was thinking of replacing all of the original fuel injectors too. Is there a mileage interval that the fuel injectors need to be replaced? Do these need to be replaced or can they be cleaned and re-used? Just wanted to take care of my car; however, don't want to waste money.

Here is a copy of the work order quote:


__________________________________________________ ________________
Job01 Oil Service Labor: 0.8 hrs@$84.89/hr=$67.91
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72116 Oil filter 1.0 @ 16.28 =$ 16.28
20W50 20w50 motor oil 10.0 @ 3.79 =$ 37.90
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Change oil and filter
Lubricate chassis where applicable
Check all vehicle fluids quantity and quality Inspect windshield wiper operation Check all lighting operation Test tire pressure and adjust

__________________________________________________ ________________
Job02 Tune engine Labor: 1.8 hrs@$84.89/hr=$152.80
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SP415 Spark plug RN9YC 6.0 @ 3.47 =$ 20.82
03008 Distributor cap 1.0 @ 18.21 =$ 18.21
04017 rotor 1.0 @ 9.10 =$ 9.10
18502 Air Filter 1.0 @ 34.06 =$ 34.06
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Replace spark plugs, dist cap and rotor. Set timing and adj fuel mixture.

__________________________________________________ ________________
Job03 Valve Adjust Labor: 3.5 hrs@$84.89/hr=$297.11
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19404 Valve cover gasket,U 2.0 @ 17.26 =$ 34.52
19501 Valve cover gasket,L 2.0 @ 10.28 =$ 20.56
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Adj valves. Factory recomended interval is 15,000 miles. Time will be adjusted accordingly if done with Tune UP

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Job04 Injectors Labor: 2.5 hrs@$84.89/hr=$212.23
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502004 Fuel Injector 6.0 @ 83.07 =$ 498.42
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Replace injectors. Time will be adjusted accordingly if done with Tune UP

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Job05 Front Brakes Labor: 2.8 hrs@$84.89/hr=$237.69
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5006 Pads, Front 1.0 @ 63.17 =$ 63.17
96501 Sensor 2.0 @ 23.75 =$ 47.50
10700 Rotor, Front 2.0 @ 115.80 =$ 231.60
5641 Seal, frt hub 2.0 @ 12.40 =$ 24.80
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Replace front pads and rotors. Clean and pack front wheel bearings.


__________________________________________________ ________________
Estimate Cost Summary
__________________________________________________ ________________
Tax: $134.18
Estimate Total: $2,198.86





Thanks for your help!

[Rot 911]

Your injectors should be just fine at 68,000 miles. Try running a bottle of Techron in your gas tank a couple of times a year should keep them clean. I have 145,000 miles on my injectors and they are still working well. The prices for everything else looks reasonable although all of it could be done yourself. Usually you don't have to replace the brake sensors. Do you have reason to believe they don't work?

[Thrlls]

If you do want to replace them...or clean them check out witchhunters
However, as Kurt mentioned I don't think you need to replace them...yet. If you use the Techron, change your oil as it may get contaminated.

[guidob222]

Thanks for the quick replies guys. Before I bought my 911, the car sat in a barn for a number of years - when I had my PPI, the tech noted that one of the injectors may be bad and run techron through it. I asked the same question on PCA.org and one of their techs said injectors need to be replaced every 50,000 miles. The car seems to run fine for me - but I am no expert - I just drive it hard. I will NEVER sell the car so I am just protecting my investment/enjoyment - just didn't know if this would be a waste of money at this time. Anymore thoughts - just let me know - thanks for your help!

[guidob222]

Regarding the brake sensors - yes, I questioned that with my tech and he said he was just quoting the worst case scenario on everything. I know my rotors are good - I just replaced those when I bought the car 15,000 miles ago - if the pads aren't worn down too much, rotors are good right? Can't they be machined down even if they are warped? I know Ive down that on my old Hondas? Also - is the mileage interval about 10,000 miles for valve adjustment and 15,000 miles for a tune up? Thanks so much guys!

[Rot 911]

Did you replace the pads with the rotors? If so you have lots of mileage left on those pads. Valve adjustment is every 15,000 miles. I'd just do a tune up and oil change if it was me.

[guidob222]

Can injectors just be cleaned or do they just need to be replaced?

[911quest]

Just to ease your mind have the shop check your injectors If they deal with older CIS 911's they will know what to look for.

[Thrlls]

Originally Posted by guidob222

Can injectors just be cleaned or do they just need to be replaced?

I sent all 6 to the link I provided above, and the cost was $120.
They can do whatever you want them to do, just check out the site and/or call them with questions.

[willf]

when you are getting close to a oil change, run the techron unless you truly know that you have issues with the CIS injectors. Issues show up with hard starts for example. CIS injectors are not the same as other injectors as they can't really be cleaned or back flushed. I have had this service performed on a set of running CIS injectors from my 911 and it resulted in several leaky injectors that ended up being replaced. The CIS injectors did flow better according to the data and it was obvious when driven that the injectors were flowing more fuel. I ended up buying a full set from our host. No bodies fault, just the design of CIS injectors. BTW, I live near the "WitchHunter" and he does excellent work; I have used his injector service for my Benz, and Evolution in the past with outstanding results. Enjoy.

[LakeCleElum]

I have a new set for my 73.5, but haven't put them in as the old ones till work great 35 years later. At times, one will act up and I'll pull it and clean it, but I see no need to replace. In addition to the fuel additives listed above, put in a of the alcohol-like stuff to get any water out of the fuel a few times of year also. CIS must have clean fuel.

[Thrlls]

Originally Posted by willf

when you are getting close to a oil change, run the techron unless you truly know that you have issues with the CIS injectors. Issues show up with hard starts for example. CIS injectors are not the same as other injectors as they can't really be cleaned or back flushed. I have had this service performed on a set of running CIS injectors from my 911 and it resulted in several leaky injectors that ended up being replaced. The CIS injectors did flow better according to the data and it was obvious when driven that the injectors were flowing more fuel. I ended up buying a full set from our host. No bodies fault, just the design of CIS injectors. BTW, I live near the "WitchHunter" and he does excellent work; I have used his injector service for my Benz, and Evolution in the past with outstanding results. Enjoy.

This is good to know!
I had no idea the CIS injectors could not be cleaned or back flushed.

Sorry to mis-inform others.

[SigmundF]

So if I understand this correct there is no point to get the CIS injectors cleaned? Just have them checked and if they are OK that's good and if they are not OK, then by new ones?

[willf]

sigmundf, that is the net.

I would add that if you are having them checked, it might be a good time to go ahead and replace the injector o rings (and injector sleeves if they are damaged) as they have a tendancy over the years to become brittle and crack.

[911st]

You are probably fine.

CIS sprays fuel all the time. If they were dirty they would just squirt the fuel. Would still run fine.

There are injector cleaning company's. If you want to take top care of your car, send them out to be cleaned, checked and ballanced (they mix and match).

This might even be better than new ones.

On my MFI I tood them to a desell shop as they do this all the time.

[Fellowship]

While driving a couple of weeks ago, the car suddenly started to run like it was only on 5 cyclinders.

When this happened in the past, I paid a mechanic $200.00 to diagnose and clean an injector.

This time I pulled the injectors (that was easier than I imagined) sent them off to WitchHunters for cleaning and testing.

WitchHunters called to tell me they no longer clean CIS injectors, but could test them.

Just got them back and they all "Passed" the test. Plus, new "O" rings.

Figured I would put them back in and start trouble shooting other causes of the car to run rough.

Car started back up and runs smoother and revs better than ever before?

Not sure if removing them unlodged something that was stuck, but no complaints from me.

Feels good to have the car running smooth again!