: Can someone explain HOW my injectors went bad?



weister42
05-01-06, 02:59 AM
First, let me just say I've changed the plugs & wires, FPR, fuel filter, cleaned throttle body & EGR valve, did the WOTs every week or so, pretty much checked everything that may need to be changed. Here's my problem...

If I run my car to its normal operating temperature and leave the car off for more than 40 min or so it starts hard. It cranks but doesn't want to start(like the engine is flooded with gasoline). Applying the gas pedal makes it start faster. The engine starts perfect when it's cold or right after I shut it off even if it's warmed up. A local mechanic confirms that ALL of my injectors were seeping, so when I park my warmed car for awhile it floods my engine. He did explain why my car starts fine when it's cold but I forgot what he said. The car runs perfect when it's on.

The strange thing is this problem developed immediately after I installed an aftermarket stereo with subwoofers in my trunk. I checked all the connections and they're all good, the engine didn't throw codes or anything. How did my injectors went bad? Did bass shook loose the dirt in the gas tank and clogged/broke loose a valve or such catastrophic damage? The only possible interference I can think of is here...

http://students.uwsp.edu/hlu328/wire1.jpg

http://students.uwsp.edu/hlu328/wire3.jpg

I ran my power wires through the plastic block because I didn't want to drill holes in my car body, I carefully cut an opening on the plastic block and none of the little factory wires are touched.

Somehow my fuel system went haywire during the time I installed my stereo. The car threw a misfire code after I turned it on but corrected itself after about 2 minutes. I've been driving my car with this problem for 6 months now and it runs perfect and nothing else broke. I am really confused:confused:

caddydaddy
05-01-06, 09:54 AM
Maybe it's just a wierd coincedence that your injectors are seeping now? How many miles are on your Deville?

eldorado1
05-01-06, 10:56 AM
My car had 6x,000 miles when it started backfiring through the intake when I started it. Lots, and I mean lots of troubleshooting later, I found out that most of the injectors were leaking. These cadillac injectors are just terrible it seems.

Ranger
05-01-06, 11:47 AM
Have you put any "snake oil" in the tank recently?

weister42
05-01-06, 01:31 PM
I have about 102,xxx miles on my Deville and I've been using premium gas ever since I bought it two years ago, the car had 97,xxx miles on it before I got it off the dealership with no warranty:bigroll: (so it was really cheap). The mechanic told me he has never seen such a thing and he suspect someone ran something other than gasoline in this car before and ruined the injectors.

One thing worth to discuss is my fuel ppressure. This other mechanic told me my fuel pressure was way too high and he detuned it until the trim is at -5(?), maybe my fuel pressure was high for long time and something finally broke?

Does anyone know a place where I can get 8 injectors for cheap?

Ranger
05-01-06, 07:02 PM
I didn't know you could adjust fuel pressure. How'd he do that? Junk yard for cheap injectors would be my guess. Or http://www.cadauto.com/

eldorado1
05-01-06, 07:18 PM
All northstars (well, maybe besides 93-94, don't know about 2000+) come with an adjustable fuel regulator.

I would search on ebay for 24#/hr injectors. I wouldn't go back to northstar injectors of ANY mileage for ANY price.

I'd like to know what "way too high" meant though.

weister42
05-01-06, 09:00 PM
i don't remember the exact # but I think it was 52psi...but he could be lying too...this is the other mechanic who couldn't find why my car starts hard.

eldorado1
05-01-06, 09:18 PM
There are a few northstar years that have a 51 psi FPR stock, I'm guessing yours is one of them.

chevelle
05-02-06, 12:52 PM
I think it is the silver duct tape.....ack. Don't you know that the tape is supposed to be body color on a Cadillac...?? There must be another solution to sealing up the hole you cut other than duct tape. Even a carefullly applied layer of RTV would be better than duct tape.


Have you considered replacing the fuel pressure regulator first...?? Usually a leaking fuel pressure regulator is the culprit for hard hot restarting, not injectors. Although, if someone was running a lot of "fuel treatment" or other additives thru the system it could have damaged the injectors....and the fuel pressure regulator.

weister42
05-02-06, 06:57 PM
I think it is the silver duct tape.....ack. Don't you know that the tape is supposed to be body color on a Cadillac...?? There must be another solution to sealing up the hole you cut other than duct tape. Even a carefullly applied layer of RTV would be better than duct tape.


Have you considered replacing the fuel pressure regulator first...?? Usually a leaking fuel pressure regulator is the culprit for hard hot restarting, not injectors. Although, if someone was running a lot of "fuel treatment" or other additives thru the system it could have damaged the injectors....and the fuel pressure regulator.

Ive already replaced the fuel pressure regulator if you read my post carefully:thepan: The duct tape was temporary but hey it works pretty well.

chevelle
05-02-06, 11:27 PM
Duh....Missed the FPR in the first read.

Still....leaking FPR's tend to cause hard hot restarting. I would check it again.

You can also unclip the fuel rail from the intake and lift the rail up so the injectors clear the ports in the intake. Turn the key to on but not crank. This will prime the fuel pump. Watch the injectors for dripping. If the injectors are really causing the problem you should see them drip when the system is under pressure and they are not opening.

davesdeville
05-03-06, 07:31 AM
I'd vacuum test the FPR before anything else since it is possible you got a bad replacement one or it has gone bad since and since the test itself is so easy.