90 Q-45 Injectors

[Darrel]

Car dealer previously replaced 1 fuel injector and now claims I have 2 bad fuel injectors. The dealer wants to replace all of them? Should I go ahead and replace all of them?? How hard is it to replace the injectors? I do lots of mechanical repairs and have reviewed previous posts and conclude the fuel injectors fail frequently and may be difficult to replace.

Thanks for any help!

Darrel

[Q45tech]

Unusal for injectors to fail in Alabama, Georgia, South Carolina due to our more normal gasoline blends..............however that assumes there was never any out of South fuel used over the entire period.

Unfourtunately thanks to Katrina the refiners sent what they had and serious mixups occurred this Fall thru Christmas, so all bets are off now!

Huntsville to ATL is a 4 hour drive [<200miles].........contact T3 [404 794-7700] for another opinion and quote...........without knowing the resistance of each injector or injector harness condition tough to call without actually having the Q for examination.

We have never changed all injectors [always seem to find half that are good] but preempetively the dealer may be trying to avoid you spending for multiple plenum removals [T3 $600 labor ] plus some increment depending on number of injectors changed [no more than $800 for all 8] plus parts.

The injectors are expensive.............the entire replacement could be $2100.

This is an all day job taking 9-10 hours to do it carefully and correctly. Also expect some rotten hoses to be damaged in the removal process == hose parts are extra but no labor. Budget $200 more just in case.

Don't have a clue what Huntsville labor rate is but ours is $75/hr.

[Q45denver]

If you are planning to DIY. buy a used set with the rails and have the NICo sponsor Deatschwerks clean, and test them and replace the o-rings-for $9 each. You should be able to get a complete set done for under $200. That way all you have to do is bolt them onto the intake. I may have another set available in a week or so since I'm planning to convert my 1990 to use updated 1994 injectors.

[Darrel]

Please let me know if you have a set I can buy from you. That seems like the easiest solution!

Darrel

[maxnix]

Two questions.

How often have the fuel filters been changed?

Have you seen anything at the bottom of your tank when you changed your fuel pump?

You must ohm your injectors through the harness first, then ohm the failed ones directly. Throwing new injectors where none may be needed is a dealer exigency. Understand that ohming will not catch clogged nor leaky injectors.

A trip to T-3 could tell you a lot about the condition of your car and what needs to be done now to save expensive component replacements later.

[Darrel]

I haven't recently changed the fuel filters and to the best of my knowledge the fuel pump has not been replaced. It is tough putting 2K into a car that isn't worth a lot more than that, althought this car is in immaculate condition and everything works, except the injectors. The dealer has diagnosed that the 3 injector is leaking and the 5 is going bad. Are these extremely difficult to remove?

Also, I don't think the cam guides have been replaced. With 110K miles, how big a risk are they?

Darrel

[Q451990]

Also, I don't think the cam guides have been replaced. With 110K miles, how big a risk are they?

A huge risk! Mine went at 120K, but I have personally seen failures at 77K, and we have documented failures lower than that on the board. I would say the average is around 120K. You're definately driving on borrowed time.

I actually replaced all of my injectors back in 1998 after having one fail... replacing it, and then having another failure in a few weeks. Pulling the plenum is a bear, and I didn't want to do it once a month. Looking back on it I wonder if an injector flush would have cured me. I didn't ohm them... just went to the dealer and got a power balance test. They told me which one was bad and I replaced it.

I would absolutely do the ohm testing. If they check out OK I would try a rail flush first. Essentially it's a pressuirized canister (fed by compressed air) that forces a solvent through the injectors. The fuel lines are looped back to the tank and the car is run on the cleaner until it's used.

Good luck!

Heath

[Q45tech]

Get a can of BG 44k, if you notice any improvement then you get a rail flush to finish the job.

What you have to spend on an old car never correlates with what one is worth. You must gauge by what another car would cost to buy and then repair.

The long term view is hard to rationalize unless you plan to stay in the lux category [ Big MB, BMW, LS, Audi]..........you never even think about what you can get by selling these beast you drive them til you haul them to the junkyard.

We routinely do $3,000 repairs on cars not worth $2,000 after the repair BECAUSE the owner likes the car and has learned that even a $10,000 replacement wouldn't be as good.We do $8,000 engine and transmission replacements on cars that still couldn't be sold for $4,000 after the work because then you would have to spend $15,000 to find a car a good.

If you can get to ATL M-F [get up at 5AM and drive over to be here by 9AM] we can do a compelete diagnosis* in an hour [ $75] and you can be back home by 2 PM.

*Power Balance, ohm injectors, fuel pressure, etc: resolve any Consult warnings

[Darrel]

The dealer claims the #3 injector is leaking. I noticed that the car was smoking when I took it to the dealer. I really don't want to drive much in this condition. Is it possible to clean it or is does the injector have to be replaced? Is this injector easily replaceable?

Darrel

[sdkhalsa]

On my 94Q I found that after the first injector died, most of the others followed at about 3 month intervals. If you change any of injectors 3-6,located under plenum, you will probably want to do all of these because of the huge amount of labor and/or cost in removing plenum. Meanwhile, I had changed 1, 2, 7, and 8 with rebuilt injectors(at half the cost) since these were easy to get at. If you have the cash, I would recommend doing them all, as you will be going through the hassle of chasing down miscellaneous problems with the remainder. By the way, testing the resistance on the injectors gave me a very good indication of their condition, typically finding that once they were a few ohms over, that was it.

[Q451990]

I noticed that the car was smoking when I took it to the dealer.

Not easily replaceable... what color was the smoke... white? blue? or black?

Heath

[Q45denver]

If leaking, your main risk is hydrolock which could bend a rod. I've had brand new injectors fail within 10K miles. Gas dry (isoprophl alcohol) will provide some protection.