Hello everyone, I was looking around and could not find any write-up on how to replace the fuel pressure regulator and fuel injectors on a 1987 Fiero GT 2.8L stock engine. So I need anyone that has done it to please if possible to post the how to with pictures if available.

Thanks to all in advance, I know you guys always come through!


Off topic: but Daytona looks like it’s going to be great this year. Spoke to Ed Parks (The Fiero Factory) and he's going to be there this year! Plus there going to be a lot of other interesting things going on...Hope to see you all there.

[This message has been edited by 87GT2M6 (edited 03-03-2009).]

It's pretty easy really. Just take the upper and middle intake out. Move vac lines without breaking them, and unscrew the little screw that hold in the regulator which is on the fuel rail. Make sure the new one has the right gasket and treat it delicately.

Fuel injectors wiggle out (again Gently) AFTER the clips are lulled out and the old ones are disconnected. Then reverse the process in putting them in. If you search you can find other little helpfull details that will add to what I have said.

Start with the intakes first.

quote Originally posted by blkpearl: It's pretty easy really. Just take the upper and middle intake out. Move vac lines without breaking them, and unscrew the little screw that hold in the regulator which is on the fuel rail. Make sure the new one has the right gasket and treat it delicately. Fuel injectors wiggle out (again Gently) AFTER the clips are lulled out and the old ones are disconnected. Then reverse the process in putting them in. If you search you can find other little helpfull details that will add to what I have said. Start with the intakes first.

Thanks I did not realize it was that simple. Now I have to save up and hunt down the regulator and injectors.

thumbs up to you

Actually you dont have to remove the middle intake manifold. You only have to remove the upper intake manifold (the one that is powder coated red).

-Unbolt the throttle body (you can choose to remove the coolant lines or not, just easier if you do)
-Unbolt the upper intake manifold - use a 12 point 10mm socket on the chrome head bolts.
-When you remove the upper intake, like "blkpearl" said, be very careful with the vacuum lines! Dont break them! If you do, you will be wondering why your car wont idle right, or why your exhaust manifolds are glowing red after you get it back together!
-You need to relieve the pressure from the fuel rail. There is a shrader valve (like what is in your tire to inflate it) under the cap on the left side of the fuel rail. Depress the valve (hold a rag around it so you dont cover everything with gas) and the pressure will be released.
-Remove the fuel injector plugs (wires) and mark them to where they go (makes it easier when you reinstall
-Remove the hard fuel lines
-Remove the two 10mm bolts that hold the fuel rail in place. After you remove those two bolts, pull the fuel rail straight up. If you need to, you can use a pry bar - BUT BE VERY CAREFUL and dont force it!
-When the fuel rail is removed, you can remove the fuel injectors.
-Remove the fuel regulator. You will need to use a "safety torx" bit to remove the screws. I forget exactly what size the safety torx is, but im sure someone will be able to chime in.


Installation is just reverse of removal. You can put a little dab of vaseline on the rubber o-rings that are on the fuel injectors to help them slide in when you reinstall them

That should be step by step, I dont think I forgot too much. If I did, im sure someone will let you know. Either way, its pretty straight forward, and you will see what needs to be done!

If you need any more help let me know!
Chris

This is a picture of my engine bay last summer when I was poking around in there. I didn't have my injectors out (but I should've). Does the distributor have to come out before removing the cold start injector?

[This message has been edited by Patrick (edited 03-04-2009).]

If you don't already have one, you really should get a Haynes Manual. When reinstalling the upper manifold, follow the torque sequence in Part B of the V6 engine section. The Haynes Manual doesn't state that the distributor needs to be removed to replace the cold start injector, but it might best be accomplished while you've got the upper intake removed. Replace the O rings on it and lube them with oil before reinstalling.

no the distributor does not have to be taken out

Thanks for the feedback on the removal of the cold start injector, guys.

Another question, relevant to discussion of injectors and fuel regulators...

I suspect leaking injectors in my GT as its gas mileage is terrible. I realize a fuel pressure gauge is what I need for a proper leak-down test, but I don't currently have one. So... how long should the system stay pressurized when the engine is turned off so that the fuel pump doesn’t turn itself on when the key is turned back to the “on” position? I’m finding that my GT’s fuel pump will come back on within 15 seconds of the engine being turned off with the key in the “on” position. If anyone can follow what I’m saying , does that seem to indicate that the “leak-down” is occurring much too rapidly?

[This message has been edited by Patrick (edited 03-05-2009).]

You guys are the best. Thank you all for your help.


I'm sure I can do this now with no problems.

Patrick, the fuel pump is not fuel pressure activated. It's designed to run continuously, with unused fuel being recycled back to the tank via the return line. The fuel pump is activated either by an ECM-controlled relay or a manual oil pressure switch in the case that the ECM or relay is bad. The ECM turns on the pump to prime for 1.6 seconds upon first key turn to RUN then shuts it off. It will stay off until the ECM see reference pulses from the ignition module via the EST wire. If the engine quits the EST pulses stop and the ECM turns off the relay, but it can take seconds for oil pressure to bleed down enough to turn off the manual pressure switch so the pump will continue running for that time.


Here's another view with the plenum removed:



To the original poster: Once the plenum is off, fuel lines disconnected (purchase new tan O-rings from GM for line connections), and cold start injector line disconnected you remove the injector rail with injectors installed. The injectors have thick O-rings and oversized manifold holes that allow for the angularity change as you pull the fuel rail/injector assembly straight up. To remove the injectors from the rails, there are metal clips that rotate in a groove to unlock the injector from the rail. Upon reassembly, lube the O-rings with clean motor oil, just a dab.

By the way, if you leave the injectors clipped into the rail and reconnect the cold start injector and fuel lines you can manually activate the pump and visually check to see if any of the injectors is leaking.

JazzMan

quote Originally posted by JazzMan: ...but it can take seconds for oil pressure to bleed down enough to turn off the manual pressure switch so the pump will continue running for that time.

Ah, I was making the mistake that it was the fuel pressure bleeding down (rather than the oil pressure) that was allowing the fuel pump to cycle back on. Thanks for the clarification, JazzMan.

quote Originally posted by JazzMan: By the way, if you leave the injectors clipped into the rail and reconnect the cold start injector and fuel lines you can manually activate the pump and visually check to see if any of the injectors is leaking.

How, by just turning the ignition key to the "RUN" position?

It's easiest to apply 12 volts to the fuel pump terminal in the ALDL connector behind the cigarette lighter trim plate. I use the lighter orange wire as it's already fused and has enough ampacity to supply the fuel pump. Turning the key to RUN will also work though you may have to do it more than once to get full fuel pressure if the pump is weak.

JazzMan

Great, thanks very much JazzMan.

quote Originally posted by JazzMan: ...but it can take seconds for oil pressure to bleed down enough to turn off the manual pressure switch so the pump will continue running for that time.

I was just talking about this tonight at our Fiero club meeting, and after re-reading the above comment, I don't believe JazzMan understood my question, and/or I didn't properly understand his answer.

JazzMan, please re-read my question below (which I've altererd a bit from the original) and see if you feel your response actually addresses my concerns. I believe there's a misunderstanding somewhere (and yes, it could be by me!)

quote Originally posted by Patrick: How long should the system stay pressurized when the engine is turned off so that the fuel pump doesn’t turn itself on when the key is turned back to the “Run” position (with the engine off)? I’m finding that my GT’s fuel pump will come back on after (but not before) 15 seconds of the engine being turned off when I turn the key back to the “Run” position (with the engine still off). If anyone can follow what I’m saying , does that seem to indicate that the “leak-down” is occurring much too rapidly?

I'm not wondering why the fuel pump will continue to run with the engine off and the key in the "Run" position. That's not what my question was about.

I was wondering why it takes about 15 seconds after the engine is turned off before the fuel pump will come back on if the key is put in the "Run" position with the engine off. What does the fact it takes 15 seconds (and no less) mean? Is this good or bad in regards to fuel pressure leak-down. Is this even related to fuel pressure leak-down?

If anyone knows what I'm talking about and feels there's a better way to ask, feel free to jump in and comment!

[EDIT] I finally bought a fuel pressure tester, so I'm going to get to the bottom of this possible fuel pressure leak-down issue one way or another.

[This message has been edited by Patrick (edited 03-15-2009).]

quote Originally posted by Patrick: I'm not wondering why the fuel pump will continue to run with the engine off and the key in the "Run" position. That's not what my question was about. I was wondering why it takes about 15 seconds after the engine is turned off before the fuel pump will come back on if the key is put in the "Run" position with the engine off. What does the fact it takes 15 seconds (and no less) mean? Is this good or bad in regards to fuel pressure leak-down. Is this even related to fuel pressure leak-down? If anyone knows what I'm talking about and feels there's a better way to ask, feel free to jump in and comment! [EDIT] I finally bought a fuel pressure tester, so I'm going to get to the bottom of this possible fuel pressure leak-down issue one way or another.

There are no sensors in the fuel system at all, so the ECM has no way of knowing if the pump is running. The ECM can assume the pump is running when it sends power to the relay coil, but I doubt the programming in the ECM has any awareness of the fuel pump status. AFAIK the fuel pump is activated for prime (1.6 seconds) each time the key is turned from OFF to RUN, and is commanded to run 100% of the time that the distributor is producing EST pulses.

It could be your pump has something wrong with it that prevents it from starting to turn if there's any residual pressure left in the line, but that's the only thing I can think of.

JazzMan

JazzMan, thanks for your input.

I bought a fuel pressure gauge a few days ago and I thought I'd better take advantage of the fact that it wasn't raining today, so...

Fuel pressure with key on/engine not running is 41 psi.

With the engine running at idle it's 33 psi.

With the system primed to 41 psi and key off/engine not running, the pressure slowly drops to 30 psi within 30 minutes.

Is this an indication of something (injectors, regulator, etc) leaking which needs attention, or is this within tolerances?

didnt notice ayone mention the most trecherous part:
disconnecting the EGR
this stupid brittle tube
easy to break
unless your EGR system is already kaput - may want to think about having a replacement ready for this
not only because you original one will probably crack, but because the original one is porbably also fully clogged

Patrick

TOT..from your picture, is that hood support original equipment....

quote Originally posted by Dodgerunner: Patrick TOT..from your picture, is that hood support original equipment....

Heh heh, it's only required if there's a breeze blowing while I'm working under the decklid. Don't ask how I discovered this!

And now Rory, how about a quick comment on my fuel pressure readings please.

(OK, just re-read you post and the 33 is at idle so your right on the edge. But since it say it can drop 10 psi at idle from you 41 then guess your ok. )

Just my opinion, I would not worry about the static pressure drop over 30 min. that is not to high and could be the reg., injr(s), or even the pump check valve.

However the running pressure being 33 is lower than you want to see. The book says it should not drop below 40psi.

The book specs say static pressure (key cycle not running) should be 40.5-47 psi. Once the engine is started and at idle should only drop by 3-10 psi. But off idle should be closer to the 40 psi..

Hoods in the wind... Yes my Intrepid trunk lid is really good at that on a windy day. Once layed me out in a parking lot for a min. or two...

[This message has been edited by Dodgerunner (edited 03-27-2009).]

quote Originally posted by Dodgerunner: ...then guess your ok.

Yeah, not that I know much about EFI, but I suspected the fuel pressure leakdown test results were probably acceptable.

Well, I still need to figure out why I'm getting 14 mpg. The GT actually runs great, but this gas mileage sucks (literally).

The next thing I'll try is to replace the EGR tube and put back the stock ECM chip. I've had a custom "EGR delete" chip installed since last summer when I discovered the EGR tube was cracked and I blocked it off.

I also need to fix the "tick, tick, tick..." front exhaust manifold leak as I hear this can fool the O2 sensor and create a rich condition. I'm NOT looking forward to THAT job! (as I know at least one bolt was broken off in the head by the PO)

[This message has been edited by Patrick (edited 03-28-2009).]