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New injectors - Bosch Design II?


jtmarten
07-17-2012, 06:12 PM
Looks like I have a couple bad injectors. Bad misfire, esp under load. I replaced the plugs and wires, still persists.
Took it in to have it diagnosed: they checked all the usual things, the tech 'thinks' leaking injectors is the problem. They want $535 to R&R the plenum and leak down test, plus $300 for each bad injector!

I think I'll replace the cam position sensor first, but it did have a couple black plugs when I changed them, so most likely it is the injectors.

Has anyone replaced the crappy originals with the Bosch Design II injectors? Better reliability? No issues/problems with installing them??

Thanks!

j cAT
07-17-2012, 08:30 PM
Looks like I have a couple bad injectors. Bad misfire, esp under load. I replaced the plugs and wires, still persists.
Took it in to have it diagnosed: they checked all the usual things, the tech 'thinks' leaking injectors is the problem. They want $535 to R&R the plenum and leak down test, plus $300 for each bad injector!

I think I'll replace the cam position sensor first, but it did have a couple black plugs when I changed them, so most likely it is the injectors.

Has anyone replaced the crappy originals with the Bosch Design II injectors? Better reliability? No issues/problems with installing them??

Thanks!

what about a fuel pressure test. fuel leak down etc..

check distributor for wear etc

jtmarten
07-17-2012, 10:17 PM
They checked:
dizzy gear
fuel pressure
timing
plugs
engine data
reflashed PCM (which sucks, had it programmed for 'towing' with the F.A.S.T. programmer, prob screwed now)
cleaned MAF; He said the MAF was dirty; but I don't know how, I just pulled it and cleaned it when I installed new plugs, wires, and air filter a few weeks ago (maybe have driven 100mi since then)

Just as a side question: there is a vacuum line on the passenger side that is toast, but I don't know where it originally went; couldn't find an open vacuum port in the area. Its connected to what looks like a dashpot located just above where the rear A/C lines connect. Saw it when I was installing the plugs blocking off the rear A/C. Any idea where that may go?

777stickman
07-18-2012, 09:58 AM
Just as a side question: there is a vacuum line on the passenger side that is toast, but I don't know where it originally went; couldn't find an open vacuum port in the area. Its connected to what looks like a dashpot located just above where the rear A/C lines connect. Saw it when I was installing the plugs blocking off the rear A/C. Any idea where that may go?

I think what your talking about is called the heater control valve. The rubber vacuum line runs up to a hard plastic line towards the rear of the motor. That line then runs over the top rear and to the drivers side for the vacuum source.

This is on my '98 Sub 7.4.

jtmarten
07-18-2012, 10:29 AM
I think what your talking about is called the heater control valve. The rubber vacuum line runs up to a hard plastic line towards the rear of the motor. That line then runs over the top rear and to the drivers side for the vacuum source.

This is on my '98 Sub 7.4.

Thanks, I'll check it out tonight. Wasn't sure if it could be a possible source of my current problem.

jtmarten
07-23-2012, 11:23 AM
Well, should have the bosch design II's tonight. Have to finish up the new cooling system install on the 850Ci first though. Just hate getting parts from online vendors that have no idea what they're doing. Calls for 6&7 rib belts, received 5&6 rib belts. Once I get it buttoned back up I can start working on the 'burb and get the injectors in.

Other than a new plenum gasket, any other gaskets needed?
New o-rings for the fuel rail maybe??

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