How to remove fuel rails?

I'm in the planning stages of a UIM/LIM replacement. I have never removed the fuel rails before, I'm unclear on exactly what I'm supposed to do to get them out of the way.

First - how does one relieve pressure in the fuel line?
Next - do I remove each fuel injector from the manifold, then lift the rails up? How are the injectors removed? Or is there something different I should do?

Thanks!

It would help to know what model and year your GP is, and what engine you have.

I did my fuel injectors back in September I believe. I have a 2000 GP with a 3.1. I released the fuel pressure by letting it sit overnight. You'll need to drain off some antifreeze so that you can remove the plenum without losing antifreeze all over the engine and into the intakes.
Then after getting the plenum off and other things out of the way, disconnect the main fuel line from the fuel rails. There is a couple of bolts holding the rails to the lower intake manifold. Carefully pry off the rails and fuel injectors as a whole unit. You will have to replace the seals on the injecotrs when you put it back together. The injectors can be removed from the rails by pulling on them carefully. The electrical connectors to the injectors have plastic lock pieces on them that have to be pulled up to disconnect the connectors on the injectors. There should be a connector for the fuel injector bundle that you can disconnect before you lift the rails out.
Hope this helps. You should have a repair manual on hand as well to guide you. Good Luck.

Oops, sorry, it's a 97 GP with 3800, no SC. Thanks for the info.

I forgot to mention there is a kind of clamp that holds the injectors to the rails that have to be removed before you can take the injectors out of the rails.

The most convenient way to bleed off fuel pressure is to remove the fuel pump fuse while engine is running and let the engine consume what is left of the fuel in the lines. Other options are at the fuel filter or the Schrader valve located at the fuel pressure regulator.

On a SII 3800 you will have at least three retaining nuts at three brackets on the complete fuel rail assembly. Once they are removed you will pull up all as one piece. The fuel injectors will pop out of the bosses in the lower intake manifold. It is up to you whether you want to remove the fuel pressure and return lines from the rail. You do not have to but you will need a fuel line removal tool. I would leave the fuel lines connected and tie the fuel rail up with some string. Before removing fuel rail make sure all rear bank spark plug wires are out of the way. Also, disconnect the electrical connectors to each fuel injector, any sensors that need to be disconnected and get all wiring harnesses in the way moved for clearance.

The fuel injectors will remove from their location on the fuel rail by removing the clip at the top of each fuel injector. It is recommended to replace both upper and lower injector o-ring seals with new ones.

Excellent! Thanks.

I am shopping for a replacement plenum.

Do the Delphi or Dorman plenums come with the modified "stovepipe", the metal tube runs up from the intake manifold?

I called my Ponitiac dealer, they only sell that piece with the modified plenum. They said it runs around $150, so I'm wondering if I should go with GM instead of aftermarket.

I would go with the Dorman Kit, PN: 615-180. It has the improved plenum, reduced diameter EGR stovepipe, and gaskets, etc. If you go with the GM plenum I believe you will need the UIM gasket GM part # 89017554. GM UIM plenum part number is 89017272. Another popular aftermarket brand UIM is APN which has a smaller EGR stovepipe than the Dorman. The Dorman Kits run around $130-$150 complete.

For LIM gaskets GM has the new aluminum framed ones out now. GM part # #89017816.

Thanks a lot bnaylor. I'm going to go with the Dorman. I stopped at the dealer on the way home, which was somewhat disappointing. They had the plenum, opened it up - nothing but the plenum. They didn't have the gaskets in stock. When I asked about the stovepipe, they drew a blank - apparently they don't make a modded one.

There's also two different designs of LIM gaskets, one with locating pins, one without. Mine's an early '97, we haven't figured out which one I need yet.

Q - How is the old stovepipe removed from the intake manifold? A mallet or something?

Thanks.

Good choice on the Dorman. GM did have a modified EGR stovepipe for '97-'98 models but it was part of the LIM repair kit. It is listed in the first TSB in that PDF file I sent you earlier. But I would pass on it since you will not need a complete LIM with the Dorman Kit. I would recommend checking to make sure the LIM is true at the flanges before re-installation. It may need to be milled but hopefully it will be OK.

As to old EGR stovepipe removal, it is a press fit so mallet, vice grips or any method that works for you. Good luck.

Many thanks bnaylor. A few more Q's if I may...

I'm looking at either Permatex hi temp Ultra Black or Red for the LIM. Either one OK?
*edit* - nevermind - the FelPro LIM kit comes with RTV.

When it comes to RTV application, I'm a little unclear on exactly what areas of the gasket to apply it to.

Once I apply the RTV, do I set the gasket in place and reassemble right away? I've read about a "setup time" of 30min - I assume they mean before the engine is running?

The RTV is only used where the side intake gaskets meet the end seals on the 3800. Do not apply any RTV on the side gaskets near the intake ports, as fuel eats RTV. Allow the RTV to skin slightly (10-15 min) before installation of the intake, to keep it from sticking to the manifold and moving out of position causing a leak. Allow the RTV to completely cure before starting the engine, usually over night.

The most important part which is overlooked are both the UIM and LIM bolts. The old bolts will have old threadlocker that will need to be cleaned off so you can re-use the bolts. Or you may replace with new but they are not TTY bolts.

Be advised that GM revised the UIM bolt torque figure in 2004 from 89 in-lbs to 11 ft-lb. The LIM bolts are still 11 ft-lbs. Follow the proper torqueing sequence as seen in the PDF file especially for the LIM. There are 12 LIM bolts and some are different size in length so do not get them mixed up.

You guys have been very helpful. I have exhaustively read through every post here on "intake", "manifold", and "plenum". I still have some questions, so I'm just gonna go for it. Here we go...

1. Which LIM gasket set?
There is "1st design - End seals not equipped with locating pins"
and "2nd design - End seals equipped with locating pins". I don't know which one I need. The car in question is a '97 GP with a date of 10/96 on the door sticker. The dealer says he doesn't know any way to tell without tearing down and looking. I will likely end up buying both kits to be safe, unless someone knows how to ID?

2. RTV application
This pic was in the PDF kit. So I should apply RTV like this, lay the gaskets down, then apply in like manner to the other side of the gaskets?
http://i5.photobucket.com/albums/y183/guitarfish/Other/RTVApplication.jpg

3. Revised UIM torque spec
If GM revised the UIM torque spec from 89 in lbs to 11 ft lbs (which is 132 in lbs), this means the plenum is going to be a LOT tighter than originall spec'd, right? Even tighter than the LIM bolts? I don't want to crack the thing.

4. Injector o-ring kit
GM p/n 12537425 - Lists for $62. Is this a complete kit for all 6 injectors? Dealer wasn't sure.

You guys have been very helpful. I have exhaustively read through every post here on "intake", "manifold", and "plenum". I still have some questions, so I'm just gonna go for it. Here we go...

1. Which LIM gasket set?
There is "1st design - End seals not equipped with locating pins"
and "2nd design - End seals equipped with locating pins". I don't know which one I need. The car in question is a '97 GP with a date of 10/96 on the door sticker. The dealer says he doesn't know any way to tell without tearing down and looking. I will likely end up buying both kits to be safe, unless someone knows how to ID?

2. RTV application
This pic was in the PDF kit. So I should apply RTV like this, lay the gaskets down, then apply in like manner to the other side of the gaskets?
http://i5.photobucket.com/albums/y183/guitarfish/Other/RTVApplication.jpg

Personally, I'd go with the new aluminum framed LIM gaskets. I do not recall whether the end gaskets in the newest gasket kit are pinned or unpinned. Plus, the coolant passage seals are improved. In the procedure the RTV was added because the older LIM gaskets had a deficency in the area of the coolant passages but it is not necessary to do it with revised LIM gaskets. However, I would apply the RTV to the four corners of the end gaskets as seen in the pic regardless of which LIM gaskets are used.

http://i5.photobucket.com/albums/y186/lizzywiz/limaluminumlimqo8.jpg


3. Revised UIM torque spec
If GM revised the UIM torque spec from 89 in lbs to 11 ft lbs (which is 132 in lbs), this means the plenum is going to be a LOT tighter than originall spec'd, right? Even tighter than the LIM bolts? I don't want to crack the thing.

Were are only dealing with a few ft-lbs difference. If you are going with the Dorman you should have no problems with the 11 ft-lbs. The Dorman UIM plastic is reinforced and thicker. But the decision is yours.


4. Injector o-ring kit
GM p/n 12537425 - Lists for $62. Is this a complete kit for all 6 injectors? Dealer wasn't sure.

That sounds right to me including what the dealer is charging $$$ which is about retail price. There should be other o-rings in the fuel injector o-ring set like the fuel pressure and return line o-rings and maybe the o-ring for the fuel pressure regulator.

For what it's worth, there are two sets of aluminum framed. The set you show, 89017816, with the pins, or 89017400, without the pins.

For what it's worth, there are two sets of aluminum framed. The set you show, 89017816, with the pins, or 89017400, without the pins.

According to my sources the unpinned 89017400 part number was replaced with 89017817. The most common aluminum LIM gaskets available are the 89017816 pinned but it doesn't mean it will be right for your year model. :dunno:

You can get injector o-rings at Autozone or Advance for a whole lot cheaper than $62. Save the $50 for something else.

I am planning to use Permatex Ultra Black gasket sealant for the LIM seal ends. I'm thinking it will be applied around noon on the day of the repair. Do you think I could start the car about 6 hours later? How long is the minimum curing time?

I looked at the directions on my tube of Permatex Hi-Temp RTV Silicone sealant (red) and its says :

"Silicone cures in 24 hours."

wlkjr - I ordered the o-rings from AutoZone - $12. These are upper & lower for the injectors, but none for the main line, which is OK, since I'm not disconnecting that. Thanks.

Now, for anyone -
The lower bolt on the throttle body bracket looks quite difficult to reach. What tool do you guys use? An open end wrench is the only I could think of, but I don't know if I can get in there. Any tips? I always scratch my head over why they make things unnecessarily difficult like this.

Now, for anyone -
The lower bolt on the throttle body bracket looks quite difficult to reach. What tool do you guys use? An open end wrench is the only I could think of, but I don't know if I can get in there. Any tips? I always scratch my head over why they make things unnecessarily difficult like this.

If you are referring to the bracket on the left hand side looking in next to the thermostat housing I don't recall having to remove that initially. Just remove the top bolt at the throttle body with an 8mm open end wrench or small 8mm socket.

The 10mm nuts (X3) that hold the throttle body on to the UIM are harder to get to.

If you are referring to the bracket on the left hand side looking in next to the thermostat housing I don't recall having to remove that initially. Just remove the top bolt at the throttle body with an 8mm open end wrench or small 8mm socket.

The 10mm nuts (X3) that hold the throttle body on to the UIM are harder to get to.

You just made my night! :bananasmi

I'm looking at doing the job Friday if all the parts arrive.

Hey guys, I started my manifold job today. My Lord I'm beat. Started at 2:15p, went 7 hours non-stop. This included replacing the rad bottom hose which was a real Momma to do.

Presently, the manifolds are back on, the fuel injectors/rails are installed. All that's left is to reconnect all the electrical stuff, put the alternator/belt/air intake back on, and fill it with coolant. I figured I'll run it to operating temp, then shut down, change oil, and check for leaks.

Some notes...

My '97 was made in 10/96, it uses the "first design" gasket. The locating pins they refer to are on the side gasket seals. First design has no locator pins, second design does. Whatever. I used black RTV on the seal ends, everything went together pretty well.

There was no melting or cracking on the plenum, it looked fine. Both upper and lower gaskets were leaking thoguh and I found some cracks in the gaskets. I installed the new Dorman plenum anyway.

Dorman says not to pull/replace the stove pipe if it's not damaged or loose. Mine was tight as can be, so I left it alone. Like I said, the original plenum never cracked, so I'm not worried about it.

When it came time to torque, the darn wrench I rented at AutoZone started at 25 ft lbs and went only higher. No way to measure 11. Great. Called a friend who's rebuilt 5 engines. Says he doesn't torque manifold, only heads, pistons, etc. He told me to tighten them in pattern 4 or 5 times around, nice & easy. Then found a different friend with an old needle torque wrench. Oh boy. I had them pretty much where I felt the should be, based on how they were at removal. I checked them with his torque wrench, and it showed I was pretty darn close. Always an adventure.

I chipped the plastic tip on one of the fuel injectors when replacing the o-rings. Crap. Those are $75. I don't know if it will affect anything or not. Guess I'll find out. Anyone have experience with this?

I never removed the spark plug wires, I was able to move them off to the side. I also didn't remove the tensioner either. I loosened it, and was able to tilt the manifold up & off the plastic elbow without too much trouble.

This was the hardest job I ever did, in terms of intensity/complexity. I hope this solves the disappearing coolant problem. Tomorrow we find out.

OK, this isn't funny. I got the rest of the car together this morning, went to install the belt, and the belt tensioner pulley wasn't retracting far enough, and the bolt was slipping. Turns out the tensioner threads are stripped. :banghead:

So, now I need a new tensioner. So I won't know how the gasket repair went today. :thumbsdow

Hang in there. You are doing fine. :thumbsup:

Thanks for keeping us updated. I'm surprised your tensioner didn't go sooner. The '97 models had flaky ones in the first place. Good luck.

The job is DONE!

Old tensioner was a PITA to remove, but new one is installed and is much better than the old one. Filled the car with coolant, started her up with no prob. Took a ride around for 10min until the temp needle rose and fell, then back home for the oil change.

Preliminary check shows no leaking anywhere around the manifolds. Will top off with coolant, and spend the next week checking the level and hoping for the best.

Thanks bnaylor for all the help!!!!

-Dave

bnaylor, I have a question.

I needed to add some coolant tonight to the repaired 97 GP. About a cup to the rad and I added some to the recovery tank which was empty. I suppose it's possible the system was bled all the way or something, who knows. Of course I'm already panicking.

I know there aren't any leaks at any hoses, heater bypass elbow, rad cap, heater core. Now with the UIM/LIM gaskets replaced, all looks good there. There's no evidence at all of any coolant in the oil. I haven't observed any unusual smoke/steam from the exhaust, nor does it smell like coolant.

What does this leave for possible leak areas? A head problem or something?
I haven't checked freeze plugs, come to think of it.

Thanks,
-Dave

If it were an external leak you should see coolant leaking some where on the engine block or on the ground. Especially since the reservoir is getting drained. Only other thing I can think of is check the transmission fluid level to make sure the radiator is not bad since ATF flows through it to cool. Other possibility would be a head gasket but you don't seem to have the driveability problems.

I'd top off coolant and try bleeding again. Then monitor coolant level and go from there. Plus crawl underneath the engine and inspect using a good light source.

BTW - Forgot to mention you should consider getting the cooling system pressure tested.