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Hello everyone,
I am tearing into my 1988 Turbo 2 10th Anniversary to try to track down a miss fire issue. I got into the fuel system and I’m at a loss and need some help.
The previous owner was a real hack job and I have been trying to fix his mistakes since I acquired the car. He mentioned he did some fuel system work, but noted he “recommended” that it be redone. I can see why he said that now. I took the fuel rails off to access the injectors and found a mess of a job. Leaking lines held together with screw clamps and Corbin clamps... it was a real mess guys!
After taking things off I started to realize that not every thing is stock and I can’t seem to identify what I have here. The primary injectors I looked up on the forum and found them to be stock 88 turbo injectors. However the secondary’s are white/grey in color on the top but the identification numbers have been removed? Any idea on what size they might be? I’ll attach pictures.
When researching the fuel rails, they do not seem to be stock 88 turbo rails. The fuel pressure damper is missing along with the regulator. Can anyone identify these rails???
Lastly the way he had the fuel lines are run doesn’t seem to jive with anything I have seen posted in the forums anywhere. I would like some help with figuring out the proper way to route them. Or if the way I have shown is proper.
***Note***
The car had run excellent! Lots of power, no flooding, starts hot and cold every time. Simply took them off to have them cleaned as part of tracking down a miss fire I’m looking for.
Any help would be greatly appreciated!
Much thanks
Josh Secondary fuel rail. Notice the fitting with rubber connector. Primary fuel rail with some kind of damper. Not the normal one i see on s4 Red ones where primary position/ white on secondary Id numbers scratch off? How the lines where run when I removed them
The primary fuel rail looks to be from a S5. The S4 pulsation dampeners were prone to leak when they got old and the S5 was less likely to develop them so it's common to replace the S4 one with the S5.
its funny that they changed the routing, but i guess the S5 rail didn't accommodate the stock way. it doesn't matter, as long as the regulator is at the end, and it seems to be.
send those injectors off to get tested, it'll tell you how big they are
Yes I agree that appears to be a S5 primary fuel rail on further comparison. Wonder why he switched them? What about that secondary rail. Can’t seem to find one that matches it anywhere?
I will be sending the injectors out for cleaning and testing soon. I’ll have the results posted when I know about the weird white ones. I wonder if they have been rebuilt before? Why would someone remove the info like that?
as far as routing is concerned good to hear it doesn’t particularly matter. Might take this opportunity to do a parallel system, we will see. More updates to come
Do you have a Stock ECU?
I wonder if your ECU is modified RTek. Look@ the ECU and there should be a sticker on it 7 or markings. If they have rubbed off your will have to open the ECU. http://digitaltuning.com/index.php?pid=rtek7
What is crazy if the tops of the white injectors look smaller than the red ones.
And you fuel rail looks to be machined and or have bungs inserted.
Yes the removal of Fuel Dampener and replacement with that bolt is consider more a of a safety function since the FPD are known to leak and cause fires.
Routing seem good on primary rail. And looks like S5.
Cleaning and testing the injectors is your best bet to see what is going on with them.
FYI the Corbin clamps are stock fuel system clamps.
But the crimped one on the rail is not.
Last edited by mr_vaughn; Jan 15, 2021 at 11:57 PM.
Wow Mr. Vaughn good eyes sir!!! I didn’t even realize until you said something but you are completely correct. The red injectors which I have confirmed to be factory 1988 turbo injectors measure 10.45mm on the top. The unknown white injectors measure 9.75mm on the top. I measured the opening In the fuel rails. The primary rail openings are 11.00mm the entire way. The secondary rail has two steps in the opening. The lower portion is 11.00mm but at the top where I believe the o ring will seat is 10.00mm. The mystery continues as I still can not find a fuel rail that matches the secondary rail. I have searched the web and can’t find one that matches it. It is obviously a 13b rotary fuel rail of some kind, most likely s4 or s5 but it may have had some custom work done to it? I will attach some photos for reference on what I’m seeing
This is an S4 fuel rail. Closer to what I have but notice mine doesn’t have the bolt on FPR This is an S5 rail. Vastly different from what I have. Notice this appears to be a stamped vs cast in construction. Also notice the fuel hose barb coming directly off the rail on the right side
As far as the ECU is concerned I believe it to be a factory unit that has never been tampered or removed. I can’t confirm this yet, I’m going to have to pull it to be sure. But I did have to get a fuel cut defender so it for sure doesn’t have that in the ecu programing. I was hitting fuel cut at the factory S4 setting of around 7psi. I’m not sure anyone would go threw the trouble of modifying the ECU to make these injectors work and leave the fuel cut on?
Having the FCD in place would be need to if the white injectors are bigger in CC size to enable the system to add enough fuel.
Get injectors identified and check the ECU for Modified Rtek. before doing anything else. Depending on the Rtek version they come with many features/functions depending on model.
Also check the injectors connectors and harness for any modifications to see if they are not the same and share that.
Sometimes there are resistors inline to the injectors added either near the ECU or near the injector if either running low impedance and high impedance injectors are needed.
If you can afford down time, just send the injectors to get cleaned/flow tested. At least then you know what you’re working with, or use a wideband to verify.
