Quick question on fuel injector replacement...
Nordschleife Master
Joined: Jun 2006
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From: ɹəpun uʍop 'ʎəupʎs
The brown foamy stuff is the fuel-rail insulation.
If thats in tatters, and the oil breather hoses are disintegrating, your car needs to have the intake off and the intake refresh work done. On the bright side, an intake refresh will result in working knock sensors which will increase the power of your car noticeably
You should also check the throttle position switch - you can measure resistance at the pins to the LH ECU in the passenger footwell, to make sure it registers idle and WOT positions (I can't remember which pins off-hand but a search here will bring up threads about it). Odds are the WOT switch isn't registering full throttle, which will also hamper your rapid progress down the road
If thats in tatters, and the oil breather hoses are disintegrating, your car needs to have the intake off and the intake refresh work done. On the bright side, an intake refresh will result in working knock sensors which will increase the power of your car noticeably
You should also check the throttle position switch - you can measure resistance at the pins to the LH ECU in the passenger footwell, to make sure it registers idle and WOT positions (I can't remember which pins off-hand but a search here will bring up threads about it). Odds are the WOT switch isn't registering full throttle, which will also hamper your rapid progress down the road
Rennlist Member
Joined: Oct 2004
Posts: 10,717
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From: Southern Alberta, Canada
The fuel rails came wrapped in a foam for heat and noise concerns....use a vacuum to get the pieces out before lifting the injectors.
After all fittings are loose/removed the only things keeping the rails in place are the injector Orings.....disconnect the injectors as mentioned, remove the fuel rail then the individual injectors.
The damaged hose are breathers for the cam covers.......the project now is an intake off and refresh...if they taped those hoses up gotta wonder what else they did?
After all fittings are loose/removed the only things keeping the rails in place are the injector Orings.....disconnect the injectors as mentioned, remove the fuel rail then the individual injectors.
The damaged hose are breathers for the cam covers.......the project now is an intake off and refresh...if they taped those hoses up gotta wonder what else they did?
Drifting
Joined: Sep 2006
Posts: 3,379
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From: Stratford-upon-Avon
Yes remove those square metal clips from top grooves of injectors (needle nose pliers) before gently prying the rail up at each end. It will come off leaving the injectors in situ so you can have a thorough vacuum then of all the decayed sound insulation foam.
I found the Bosch 2-pin connector removal tool handy for disconnecting the injector harness, but firm wiggling/pulling will achieve same with mabe a few skinned knuckles. Look out for the little wire spring clips on harness side of each connector.
Easier to disconnect when you've removed the plastic clips (blue from memory?) which neatly hold the harness wires together. they will be brittle and snap, so get some replacements (they're in PET which I can't consult just now) or use zip ties if you're less fussy about originality!
I replaced injectors (new ones) by first attaching them to rail as you can then be sure the square metal clips are correctly and fully engaged in grooved. I then worked the injectors back into manifold before re-connecting the rail. It's reassuring doing it this way as if you can make the fuel reconnections with rail nice and square to the dampers then you can be pretty sure the injectors are at correct height in manifold.
I found the Bosch 2-pin connector removal tool handy for disconnecting the injector harness, but firm wiggling/pulling will achieve same with mabe a few skinned knuckles. Look out for the little wire spring clips on harness side of each connector.
Easier to disconnect when you've removed the plastic clips (blue from memory?) which neatly hold the harness wires together. they will be brittle and snap, so get some replacements (they're in PET which I can't consult just now) or use zip ties if you're less fussy about originality!
I replaced injectors (new ones) by first attaching them to rail as you can then be sure the square metal clips are correctly and fully engaged in grooved. I then worked the injectors back into manifold before re-connecting the rail. It's reassuring doing it this way as if you can make the fuel reconnections with rail nice and square to the dampers then you can be pretty sure the injectors are at correct height in manifold.
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From: Boulder Creek, CA
Race Director
Joined: Sep 2007
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From: Johnson City, TN
Most folks that burst onto the scene and do cosmetics first....never get to the injectors.
Kudos for sticking with it.
The O-rings on the injectors harden and act like retainers.
Soaking them with a lube can help as you carefully wiggle/pry each loose.
Whether the TPS works or not, its probably filled with oil.
Kudos for sticking with it.
The O-rings on the injectors harden and act like retainers.
Soaking them with a lube can help as you carefully wiggle/pry each loose.
Whether the TPS works or not, its probably filled with oil.
Thread Starter
Instructor
Joined: Mar 2011
Posts: 248
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From: Fort Lauderdale, FL
Appreciate the compliment Landseer...!
I will start by removing the clips and see if I can get the rail off, then clean and vacuum around the injectors before trying to remove them from the manifold. Then do my best to replace the heat return hose and put the new injectors back in.
I will do an R & R on the intake next week, I need the car to run this week if possible because it is raining here in South Florida and I dont like riding my motorcycle in the rain. Besides this is good practice and next week or so when I disconnect stuff again it will not feel so foreign to me...
I will let you know how it goes later today.
I will start by removing the clips and see if I can get the rail off, then clean and vacuum around the injectors before trying to remove them from the manifold. Then do my best to replace the heat return hose and put the new injectors back in.
I will do an R & R on the intake next week, I need the car to run this week if possible because it is raining here in South Florida and I dont like riding my motorcycle in the rain. Besides this is good practice and next week or so when I disconnect stuff again it will not feel so foreign to me...
I will let you know how it goes later today.
Drifting
Joined: Jun 2006
Posts: 2,708
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From: Indianapolis Area
A good cleaning is a great place to start. If you can't get a vacuum hose in there to clean up first, compressed air does a good job of blowing debris out of the way. If you don't have a compressor, a leaf blower will do.
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Thread Starter
Instructor
Joined: Mar 2011
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From: Fort Lauderdale, FL
Ok so I did the Passenger side injectors, really easy to remove once the rail clips were taken off : )
I used a bottle of compressed air-spray like you use to clear a computer keyboard or internals if you build them for fun at home. This worked very well to clear around the original injectors before I pulled them from the manifold.
I then mounted and clipped the new injectors to the rail, then connected the electric cables to each and started wiggling the injectors with the rail into their spots. It was not going very well until I started to screw down the injector rail bolts which forced the injectors to seat in the manifold. Connected the fuel lines and decided to take a break before doing the driver side.
?? Curious - what would have happened if I started the car with 4 new injectors with 4 holes and 4 old injectors with 1 hole...???
Also the heat hose is toast and I will need to remove the intake to replace it...argghhh next weekend, I think (IF) the car starts I will drive it until the other parts come in.
My injectors below appear to be single shot original injectors.
I used a bottle of compressed air-spray like you use to clear a computer keyboard or internals if you build them for fun at home. This worked very well to clear around the original injectors before I pulled them from the manifold.
I then mounted and clipped the new injectors to the rail, then connected the electric cables to each and started wiggling the injectors with the rail into their spots. It was not going very well until I started to screw down the injector rail bolts which forced the injectors to seat in the manifold. Connected the fuel lines and decided to take a break before doing the driver side.
?? Curious - what would have happened if I started the car with 4 new injectors with 4 holes and 4 old injectors with 1 hole...???
Also the heat hose is toast and I will need to remove the intake to replace it...argghhh next weekend, I think (IF) the car starts I will drive it until the other parts come in.
My injectors below appear to be single shot original injectors.
Race Director
Joined: Sep 2007
Posts: 12,162
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From: Johnson City, TN
Probably be ok, as the banks are split and the impedance on the two banks would match in total.
Take GREAT care in checking for leaks on this job. You should be able to rotate the injectors a bit when installed. The seals need to stay intact. Rail seal nicks can leak muchos gasoline. Lowers can leak vac. I've had one nicked seal on an 85 reveal itself a few weeks later, too, so be sure to keep an eye on it.
Take GREAT care in checking for leaks on this job. You should be able to rotate the injectors a bit when installed. The seals need to stay intact. Rail seal nicks can leak muchos gasoline. Lowers can leak vac. I've had one nicked seal on an 85 reveal itself a few weeks later, too, so be sure to keep an eye on it.
Thread Starter
Instructor
Joined: Mar 2011
Posts: 248
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From: Fort Lauderdale, FL
Thanks Landseer, I am going to leave my rail gaurds/cover off until I do the R&R in the next week or so, this will let me see better and hopefully identify and leaks easier.
Thread Starter
Instructor
Joined: Mar 2011
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From: Fort Lauderdale, FL
Well I did it...it took me 3 hours per side (I took my time), the car fired up on within a couple seconds and I checked and found no fuel or air leaks...!!!
I drove it a little and I am suprised, it is noticably more responsive, it excellerates faster and the idle problem I had before is gone...!!!
Not bad for a Nooby huh, one you thought that only cared about the looks of the car... : )
Now I will order parts to do a intake R&R for next weekend...hoooraaah
I drove it a little and I am suprised, it is noticably more responsive, it excellerates faster and the idle problem I had before is gone...!!!
Not bad for a Nooby huh, one you thought that only cared about the looks of the car... : )
Now I will order parts to do a intake R&R for next weekend...hoooraaah
Under the Lift
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From: Buckeye, AZ
I know you checked for fuel leaks, but here's just a little added precaution about fuel leaks.... These are COMMON issues.
Check very carefully that all the injector rail clips are seated firmly in the rail slots. They should make a noticeable click when seated.
Inpect the lower o-rings all the way around for any that may have caught an edge going into the manifold. I always lube them before insertion using synthetic grease (Teflon based), although which grease may not matter.
More than just looking for leaks at the rail end fittings, put your finger under each fitting and feel/look for any slight wetness with the fuel system pressurized. I've had a bitch of a time getting some of these fittings to COMPLETELY seal. Do not overtorque them if they are found leaking/wet. Disassemble and inspect for burrs and reassemble, recheck. The alignment of the fittings may not be quite right with all the FPR and dampner brackets tightened down.
Not leak related, but also common -- on most cars I see, about half of the harness plug wire bales are ready to fall off or already have. These are held on by a smidge of plastic melted over the closed end. The plastic fractures off and wire comes loose, allowing the plug to come off the injector. Or the wire bales become projectiles when you pull the plugs off. You can restore these by remelting a spot of adjacent plastic on the plug to cover the bale wire again. A better solution is to replace the wire bales with an updated type that has little "hands" on the end of each arm. Oddly, Porsche used this type of wire bale on the Temp 2 sensor plug but not on the injectors.
Check very carefully that all the injector rail clips are seated firmly in the rail slots. They should make a noticeable click when seated.
Inpect the lower o-rings all the way around for any that may have caught an edge going into the manifold. I always lube them before insertion using synthetic grease (Teflon based), although which grease may not matter.
More than just looking for leaks at the rail end fittings, put your finger under each fitting and feel/look for any slight wetness with the fuel system pressurized. I've had a bitch of a time getting some of these fittings to COMPLETELY seal. Do not overtorque them if they are found leaking/wet. Disassemble and inspect for burrs and reassemble, recheck. The alignment of the fittings may not be quite right with all the FPR and dampner brackets tightened down.
Not leak related, but also common -- on most cars I see, about half of the harness plug wire bales are ready to fall off or already have. These are held on by a smidge of plastic melted over the closed end. The plastic fractures off and wire comes loose, allowing the plug to come off the injector. Or the wire bales become projectiles when you pull the plugs off. You can restore these by remelting a spot of adjacent plastic on the plug to cover the bale wire again. A better solution is to replace the wire bales with an updated type that has little "hands" on the end of each arm. Oddly, Porsche used this type of wire bale on the Temp 2 sensor plug but not on the injectors.