Replace one failed injector or all?

[emmett442]

For me it depends on if they are notoriously failure prone or if this is likely to be an isolated incident.

For example, back when the GM Multecs were prevalent, I almost always replaced as a set. I can't think of anything I'd still do that for today, however.

 

[Donald]

+1 on Trav comments. Can he clean and test them for you? Obviously car will be down for several days.

If some injectors are old and some new I think fuel trim compensates for then as a group. Not the best scenario

 

[cptbarkey]

Have you tried a compression test?

 

[92saturnsl2]

For me it depends on if they are notoriously failure prone or if this is likely to be an isolated incident.

For example, back when the GM Multecs were prevalent, I almost always replaced as a set. I can't think of anything I'd still do that for today, however.

I've decided to go this route. I've put enough money into the car and replacing another injector down the road (if one were to fail) isn't that bad of a job.

If some injectors are old and some new I think fuel trim compensates for then as a group. Not the best scenario

That's definitely the downside, the ECU will richen others to compensate for one that is flowing less, but that's true of any high mileage car of this era. Even if I were to purchase 4 reman injectors, the likelihood of them being precisely matched is pretty low as Trav pointed out. I'll take a shot at replacing the bad one and watch fuel trims closely on the first few drives. Engine ran great before the sudden failure, I think odds are in my favor that it will after replacement.

 

[Donald]

I've decided to go this route. I've put enough money into the car and replacing another injector down the road (if one were to fail) isn't that bad of a job.

That's definitely the downside, the ECU will richen others to compensate for one that is flowing less, but that's true of any high mileage car of this era. Even if I were to purchase 4 reman injectors, the likelihood of them being precisely matched is pretty low as Trav pointed out. I'll take a shot at replacing the bad one and watch fuel trims closely on the first few drives. Engine ran great before the sudden failure, I think odds are in my favor that it will after replacement.

Well my pickup has 8 diesel injectors times $300 a pop.

 

[zzyzzx]

You need to know if you have Fed or CA emissions, the injectors are different.

THIS!!!! And they have different gaskets too.

 

[The Critic]

I've decided to go this route. I've put enough money into the car and replacing another injector down the road (if one were to fail) isn't that bad of a job.

That's definitely the downside, the ECU will richen others to compensate for one that is flowing less, but that's true of any high mileage car of this era. Even if I were to purchase 4 reman injectors, the likelihood of them being precisely matched is pretty low as Trav pointed out. I'll take a shot at replacing the bad one and watch fuel trims closely on the first few drives. Engine ran great before the sudden failure, I think odds are in my favor that it will after replacement.

Replace one, but have the others cleaned and flow-tested.

Also, make sure you replace the upper and lower o-rings on the other 3 injectors. They tend to be crunchy and even wiggling them to remove the connector can split the o-rings.