Fuel Injector and Replacement
10-24-2003, 12:13 PM
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Fuel Injector and Replacement
Hello 928 enthusiasts,
I am new to the water cooled Porsche but I really like its handling and ride (plus its an automatic while I stuck in the traffic!) so I am going to split my weekend time and hard-earn money between this and the 930. I have a couple of questions which I hope some of you could help on this newly purchased 928. This is an 88 S4 automatic, and one of the fuel injectors has developed leak from the plastic body area. I would like to replace all 8 myself. I came across a southern CA performance shop on Internet that sold me a set of Ford D5B 19#/hr injectors. I spoke with my 930 mechanic and he lectured me that these injectors would not work and I should send them back for a refund. Has anyone out there actually replaced OEM injectors with the above D5B injectors. I was assured all flow rate and electrical were compatible with the OEM injector. Any thoughts if this should work? The second question is assuming these injectors will work, how difficult to remove the 19mm nuts from the regulators? Should I remove all 4 (two from each side of the fuel rail) in order to remove the injectors from the rail? What steps would you recommend in term of soaking the connections with penetrating oil? What other areas should I be watching out to perform the replacement? I realize this is a long list, but I would greatly appreciate any of your advise. Thanks in advance.
Tony
88 928S4
San Francisco, CA
I am new to the water cooled Porsche but I really like its handling and ride (plus its an automatic while I stuck in the traffic!) so I am going to split my weekend time and hard-earn money between this and the 930. I have a couple of questions which I hope some of you could help on this newly purchased 928. This is an 88 S4 automatic, and one of the fuel injectors has developed leak from the plastic body area. I would like to replace all 8 myself. I came across a southern CA performance shop on Internet that sold me a set of Ford D5B 19#/hr injectors. I spoke with my 930 mechanic and he lectured me that these injectors would not work and I should send them back for a refund. Has anyone out there actually replaced OEM injectors with the above D5B injectors. I was assured all flow rate and electrical were compatible with the OEM injector. Any thoughts if this should work? The second question is assuming these injectors will work, how difficult to remove the 19mm nuts from the regulators? Should I remove all 4 (two from each side of the fuel rail) in order to remove the injectors from the rail? What steps would you recommend in term of soaking the connections with penetrating oil? What other areas should I be watching out to perform the replacement? I realize this is a long list, but I would greatly appreciate any of your advise. Thanks in advance.
Tony
88 928S4
San Francisco, CA
10-24-2003, 12:23 PM
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As far as using non stock injectors is concerned, I have no information. You need to be sure and counter hold all four connections on the fuel rails when you undo them. Remove the fuel rails and the injectors as a unit. Soak the injectors with penetrating oil before you pry them out. When you replace the injectors, put them in the fuel rails with their locks first and replace each fuel rail with the injectors mounted on it.
10-24-2003, 05:33 PM
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don't know what "D5B" means, but i've been running the Ford Motorsport 19# high impedance injectors for about 6 months now. so far, so good. $220 from Summit.
now there's ford motorsport II's, with 4 outlets in the tip, instead of just one pintle.
now there's ford motorsport II's, with 4 outlets in the tip, instead of just one pintle.
10-24-2003, 05:37 PM
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Originally posted by David R. Hendrickson
don't know what "D5B" means, but i've been running the Ford Motorsport 19# high impedance injectors for about 6 months now. so far, so good. $220 from Summit.
now there's ford motorsport II's, with 4 outlets in the tip, instead of just one pintle.
don't know what "D5B" means, but i've been running the Ford Motorsport 19# high impedance injectors for about 6 months now. so far, so good. $220 from Summit.
now there's ford motorsport II's, with 4 outlets in the tip, instead of just one pintle.
10-24-2003, 05:38 PM
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I'm Running the Ford #19 lb as well. At stock pressure they will run a little rich at idle since I beleive the stock fuel pressure on the ford motor is a little less than an 87 928. No problems.
10-25-2003, 01:25 AM
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Great to hear that some of you also replaced the original injectors with the Ford 19# injector without any issue with fuel/air ratio. I got mine set of 8 with a similar price like David. They are orange and black color. Does anyone else notice any difference in power gain/loss at idle, low, and high rpm with the Ford D5B19#? Another question is do you need to use any special Porsche o-ring for the application? The Ford D5B 19# come with a smaller blue o-ring on top for the rail, and a little larger o-ring for the intake manifold. I am going to tackle this project this weekend, and I would like to know if you can share any hints and/or special attention for the removal procedure. Thanks again.
Tony
Tony
10-25-2003, 01:57 AM
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I am running the Ford 30# injectors and I have noticed quite a bit more power.
Swapping to the newer and better Ford injectors is pretty common. I have heard that they have a better spray pattern than the original Bosch injectors. I don't think I would go back to that mechanic. He would probably like to charge you $600+ for a set of the original bosch injectors.
HTH
Andy K
Swapping to the newer and better Ford injectors is pretty common. I have heard that they have a better spray pattern than the original Bosch injectors. I don't think I would go back to that mechanic. He would probably like to charge you $600+ for a set of the original bosch injectors.
HTH
Andy K
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10-25-2003, 10:59 AM
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i tried to remove a pintle cap from one of the old injectors and couldn't do it without destroying it, so i didn't do it on the new ones. i just made the porsche o-rings fit. a little tight, but they worked out ok.
one of the local guys bought the ford II's, so i'm waiting to see how they work...
one of the local guys bought the ford II's, so i'm waiting to see how they work...
10-26-2003, 03:01 AM
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Hi folks,
I removed and replaced only the right-side four injectors with the Ford D5B 19# but the new o-rings came with the purchase were too loose for the intake manifold fittings. I tried to swap the o-rings from the old original injectors to the new one but I could not insert them afterward because they became too tight with the old o-rings without any play for the intake hole. Since I could not insert them, I then swapped back and used the new o-rings with the new injectors (and insert them into the intake hole with a lot of movement/play). I have no choice but to move on and after putting the fuel rail and tighten the gland nuts to the fuel regulators together, the engine started with difficulty and could not even idle and ran erratic with no power at all. I was not sure if this problem is due to the non-Porsche specific injectors as my mechanic had mentioned or from the loose o-rings not being seated tightly in the intake holes. At this time, I cannot even drive the car (I was able to cruise on the freeway yesterday and it idled smooth without any issue before I changed the injectors today). I think I am going to have it towed to my 930 mechanic. He insisted to replace with only new Porsche specified injectors. Unless I can identify what caused the erratic idle now, I have no choice but to ready to pay him the big bucks...can anyone help with any ideas? Where can I get the Porsche S4 injectors in the Bay Area without going back to the dealer or mail ordering? If my problem is indeed caused by the "loose" injector, I would like to consider getting the Porsche set. According to the factory repair manual, how many hours does it take to replace all 8 injectors in a S4; I am contemplating to have my mechanic worked on it since I will have to pay for the parts either way. Oh well, I thought it was a straight forward project. it turns out a pretty expensive mess...
Tony
broken S4 :-(
I removed and replaced only the right-side four injectors with the Ford D5B 19# but the new o-rings came with the purchase were too loose for the intake manifold fittings. I tried to swap the o-rings from the old original injectors to the new one but I could not insert them afterward because they became too tight with the old o-rings without any play for the intake hole. Since I could not insert them, I then swapped back and used the new o-rings with the new injectors (and insert them into the intake hole with a lot of movement/play). I have no choice but to move on and after putting the fuel rail and tighten the gland nuts to the fuel regulators together, the engine started with difficulty and could not even idle and ran erratic with no power at all. I was not sure if this problem is due to the non-Porsche specific injectors as my mechanic had mentioned or from the loose o-rings not being seated tightly in the intake holes. At this time, I cannot even drive the car (I was able to cruise on the freeway yesterday and it idled smooth without any issue before I changed the injectors today). I think I am going to have it towed to my 930 mechanic. He insisted to replace with only new Porsche specified injectors. Unless I can identify what caused the erratic idle now, I have no choice but to ready to pay him the big bucks...can anyone help with any ideas? Where can I get the Porsche S4 injectors in the Bay Area without going back to the dealer or mail ordering? If my problem is indeed caused by the "loose" injector, I would like to consider getting the Porsche set. According to the factory repair manual, how many hours does it take to replace all 8 injectors in a S4; I am contemplating to have my mechanic worked on it since I will have to pay for the parts either way. Oh well, I thought it was a straight forward project. it turns out a pretty expensive mess...
Tony
broken S4 :-(
10-26-2003, 09:37 AM
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Your problem is probably the loose fitting injector o-rings, your have created a UN meter air leak (false air). You have to use the Porsche original o –rings; try using a lubricant with a twisting motion... Injectors are a match set; I would change all 8.
10-26-2003, 09:48 AM
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I agree with Steve. When I put the Ford injectors in my 87 S4 I removed the ford pintle caps, spacers and orings. The seal kit I got from 928 Spec. included the orings, pintle caps and spacers. Assemble the injectors to the fuel rail then install the rail as a unit. Good Luck and let us know.
10-26-2003, 11:23 AM
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Steve/Ed-
Thanks for the tips. I did notice the original injectors were snug tighted when I removed them from the intake. I also noticed a couple of the old injector pintle caps plastic were cracked and a bit of it had fallen into the intake.
The new injectors are now quite loose and can even be rotated or shaked slightly side by side. Is this loose fitting confirm my erratic idle problem due to air leak?
At first, I swapped the original "brown" rubber o-ring to the new injectors, but I could not forced the injectors into the intake because the thickness of the spacers on the new injectors are double the thickness of the original, and therefore create no movement to the o-ring between the pintle cap and the spacer.
I do not know how to put the old spacer from the original injector to the new injector without breaking the new injector pintle cap plastic. Therefore I moved on the project knowing something would not be right.
In any case, if I were going to order a complete seal kit from 928 Spec, is it true that the only way I can replace the correct spacer and pintle cap for the new injectors is by break the pintle cap to slide the o-ring and the spacer out. Is this the proper procedure to replace the Porsche seal kit? Is breaking the plastic pintle cap the only way to replace the correct size spacer? In the seal kit, does it come with the pintle cap, o-ring, spacer, and one more o-ring for the fue rail?
Finally, how much was the complete seal kit for all 8 injectors, and if 928 Spec the only place carries them (other than the dealer)?
I wanted to let you folks know that you have been great help for my endeavor, and now after a good night sleep, I am ready to take on the challenge again (probably next weekend or so since I have to first order the kit...) Thanks to everyone!
Tony
broken S4
Thanks for the tips. I did notice the original injectors were snug tighted when I removed them from the intake. I also noticed a couple of the old injector pintle caps plastic were cracked and a bit of it had fallen into the intake.
The new injectors are now quite loose and can even be rotated or shaked slightly side by side. Is this loose fitting confirm my erratic idle problem due to air leak?
At first, I swapped the original "brown" rubber o-ring to the new injectors, but I could not forced the injectors into the intake because the thickness of the spacers on the new injectors are double the thickness of the original, and therefore create no movement to the o-ring between the pintle cap and the spacer.
I do not know how to put the old spacer from the original injector to the new injector without breaking the new injector pintle cap plastic. Therefore I moved on the project knowing something would not be right.
In any case, if I were going to order a complete seal kit from 928 Spec, is it true that the only way I can replace the correct spacer and pintle cap for the new injectors is by break the pintle cap to slide the o-ring and the spacer out. Is this the proper procedure to replace the Porsche seal kit? Is breaking the plastic pintle cap the only way to replace the correct size spacer? In the seal kit, does it come with the pintle cap, o-ring, spacer, and one more o-ring for the fue rail?
Finally, how much was the complete seal kit for all 8 injectors, and if 928 Spec the only place carries them (other than the dealer)?
I wanted to let you folks know that you have been great help for my endeavor, and now after a good night sleep, I am ready to take on the challenge again (probably next weekend or so since I have to first order the kit...) Thanks to everyone!
Tony
broken S4