Noisy, MPG Drop After New Injectors

[DToy]

My truck started having surging issues, long cranking times, and soon wouldn't start when cold outside (50 degrees or lower). I replaced the FCA, then the lift pump, fuel filter, and finally took it into a shop. They tested the injectors and indicated that 4 out of 6 were bad and needed to be replaced. This was at 170K miles. Had them replace all 6 injectors with new Bosch 505 stainless injectors (stock, no HP increase). When I first picked up the truck it seemed to run fine, very short cranking times, etc. Soon after I noticed what sounded to me like either injector rattle or valve rattle... the engine is much louder now than it was before. Sounds like an old 6. 2L chevy. Also idles rough when cold until the engine begins to warm up. MPG dropped from 15-16 average before injectors to 10-11 with the new injectors. Power seems way down from what it was before. Been working out of state in Wyoming for last several weeks and haven't been able to get it back to the shop that replaced the injectors (3 hours away). Any ideas what could be causing the problems I'm experiencing? Would like to have an idea of possible causes before it goes back in the shop.

 

[cerberusiam]

Either one of those new injectors went bad or you got remans. My bet is there were remans but considering Bosch's QC problems it could just be a bad one in the bunch.

 

[DToy]

Either one of those new injectors went bad or you got remans. My bet is there were remans but considering Bosch's QC problems it could just be a bad one in the bunch.

They weren't supposed to be remans but who knows? How could a shop verify whether one is bad? Is it something that could kill my motor? Won't be able to get it into the shop until next week.

 

[cerberusiam]

There are test to run that will verify which injector is bad. If it is over fueling bad enough it can and will melt the piston, break the rings, wash down the cylinder, possibly score, etc. You might get lucky then again you might not.

 

[JJPage]

Hopefully you do not have a bad injector, but that will have to be verified by the shop. Other things to check would be the injector line hold down clamps(blue plastic), since the shop had them off to replace the injectors, maybe they came loose, they will rattle fairly loud if so. Also if they did not get proper torque on the cross tubes and they work loose, they will bypass enough fuel to affect mileage and power. I have little faith in outsourced work quality anymore, so just a couple of things you could check before thinking the worst. Let us know, it's always nice and useful to get feedback.

 

[DToy]

Let us know, it's always nice and useful to get feedback.

Thanks JJ, I will definitely update this thread with whatever it turns out to be. Crossing my fingers that it's not a bad injector that has done permanent damage to my motor.

 

[DToy]

Update: My truck was in the shop all week. They pulled the new injectors and sent them to Bosch in Boise to have them tested. They said 1 out of 6 was bad - failed with high return. They replaced it and truck isn't quite as noisy as before, but still has some injector cackle and mileage is still low, around 11mpg. Not sure what to do with it at this point. Guess I'm gonna have to take it to the dealer and have them diagnose it.

 

[JJPage]

Update: My truck was in the shop all week. They pulled the new injectors and sent them to Bosch in Boise to have them tested. They said 1 out of 6 was bad - failed with high return. They replaced it and truck isn't quite as noisy as before, but still has some injector cackle and mileage is still low, around 11mpg. Not sure what to do with it at this point. Guess I'm gonna have to take it to the dealer and have them diagnose it.

DToy,

Thanks for the follow up.

So were these remans? Hard to figure a new injector to be bad... My guess is they are remans, and the remaining sticks are just within specs, so they gave them a thumbs up. Sorry for your troubles.

I would try and be re-imbursed if they are remans, if they passed them off as new, give them back their crap and go forward with a different shop.

 

[DToy]

DToy,

Thanks for the follow up.

So were these remans? Hard to figure a new injector to be bad... My guess is they are remans, and the remaining sticks are just within specs, so they gave them a thumbs up. Sorry for your troubles.

I would try and be re-imbursed if they are remans, if they passed them off as new, give them back their crap and go forward with a different shop.

Not sure, but I'm starting to think they're remans. I was unde the impression that they were new, and were the most reliable option for my truck, but after this I'm not so sure. Will have to find out tomorrow.