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So I have the engine out of my 99 (with the help of a very experienced friend).
It appears that there is a manifold in the way of the rear injectors (Upper intake manifold?) and if I take it apart I will need to seal it all back.
The car has 182k on it so I want to swap out the rear injectors while the engine is out, figure I'll get the knock sensor to.
What gaskets / parts do I need to replace if I pull the manifold?
What concerns should I have when replacing the injectors?
Did a site search on the forums with google, but I'm not digging up too much. Part numbers would be especially appreciated!
Note: There's nothing wrong with the rears at the moment, but since the engine is out of the bay and there's 182k on the car, this feels like the best moment to do it. I'll leave the front three until they give me a problem, but this should keep me running smooth for a while. Rockauto said Hitachi was OEM, so I went with that.
I've used the following FelPro kit to refresh intake gaskets on all of my 4th gens over the years. I usually buy these gaskets from local parts stores.
I've used the following FelPro kit to refresh intake gaskets on all of my 4th gens over the years. I usually buy these gaskets from local parts stores.
Awesome! The Napa near me says they're getting one in tomorrow morning, so I'll grab it from them. I'm excited to get all this stuff replaced - on to 300k miles!!
Follow the instructions in the FSM (see signature for free download) for this job. Very easy and straight forward. Torque everything to spec, and in the correct sequence. Be sure to lube injectors with oil as it insert them.
I use courtesyparts.com for part numbers and nice exploded diagrams.
Don't Fogel to replace both valve cover gaskets while you are in there anyway.
Also consider replacing all injectors at this time.
They can be rebuilt to keep the price more reasonable. The injectors are old. Many members have had problems with them. Replacing all of them now saves much misery later.
Speaking of misery...... replacing the water pump while the engine is in the car is misery.
Replacing it now will be much less difficult.
Clean the egr tube while the upper intake manifold is off.
Replace coolant hoses which look iffy.
I replaced all hoses with Amazon stuff. Like 80 bucks. The water pump was 50 bucks. Aisen brand. Which is like Toyota oem.
Don't Fogel to replace both valve cover gaskets while you are in there anyway.
Also consider replacing all injectors at this time.
They can be rebuilt to keep the price more reasonable. The injectors are old. Many members have had problems with them. Replacing all of them now saves much misery later.
Speaking of misery...... replacing the water pump while the engine is in the car is misery.
Replacing it now will be much less difficult.
Clean the egr tube while the upper intake manifold is off.
Replace coolant hoses which look iffy.
I replaced all hoses with Amazon stuff. Like 80 bucks. The water pump was 50 bucks. Aisen brand. Which is like Toyota oem.
Thanks! Water pump is done I had a brand new Bosch that the former owner gave me when I bought the car.
I'm realizing that the Hitachi injectors I have may not have the O rings I need... Ugh. I need to take a look at them.
Does anyone know what size O rings I need? I'd imagine I could buy some generic ones. Sounds like there's a bunch of kit that needs to get replaced at the same time as the injectors (O rings, cushions, rail spacers...) what do I need for this?
Do I need to take off the lower intake manifold to get to the rear injectors?
I don't plan on removing the throttle body from the manifold, so do I need to replace that gasket?
If I leave the EGR attached to the manifold do I need to replace the gasket?
Can I buy new kit for the O rings at like Napa or Autozone? Seems like the ones near me don't have it in stock :P
1. No, just for the KS. Only if you have a 99 Cali spec Maxima do you have to remove the lower IM to get to the KS.
2. Nope. Some leave it attached to the UIM, some detach it during the process. It does give you a good chance to clean the backside of the TB butterfly valve which is sure to be gunked up.
3. No. But removing the two 12mm bolts is much easier than removing the whole EGR in my opinion.
4. Not sure. I always buy OEM. I either have my existing injectors serviced, which includes cleaning and flow testing, new o-rings, pintle caps and screens. Or, I've bought injectors off of Ebay that are either new, or refurbished as previously stated.
I chose to have my injectors professionally rebuilt.
All the proper parts came back with the injectors.
Others have bought a parts kit instead. I recall seeing posts by CS_AR. He has done this process.
I believe that parts kits can be found on Amazon, ebay, or Rock Auto.
Please be aware that the part which fails on the injector is the pintle cap. When they crack, gasoline will flood the cylinder. At the very least, over-fueling.
I had my injectors rebuilt by Injector RX in Houston.
They have fast turn around times. At least look at their website to learn what a proper rebuld and flow testing is all about.
Injectors in good condition save gas, add power, and lower emissions.
Don't Fogel to replace both valve cover gaskets while you are in there anyway.
The rear valve cover makes sense. And while he's in here, he might as well do the spark plug tube seals as well. OP, if you tackle this, you must follow the procedure in the FSM. Remember to use RTV in the corners, and torque is IN-LBS, not FT-LBS. Those bolts snap easy.
1. No, just for the KS. Only if you have a 99 Cali spec Maxima do you have to remove the lower IM to get to the KS.
2. Nope. Some leave it attached to the UIM, some detach it during the process. It does give you a good chance to clean the backside of the TB butterfly valve which is sure to be gunked up.
3. No. But removing the two 12mm bolts is much easier than removing the whole EGR in my opinion.
4. Not sure. I always buy OEM. I either have my existing injectors serviced, which includes cleaning and flow testing, new o-rings, pintle caps and screens. Or, I've bought injectors off of Ebay that are either new, or refurbished as previously stated.
Ok!
So if I take off the IM and swap the injectors then I need:
1) New Intake Manifold gasket
2) New EGR gasket (to make life easier)
3) New O ring for the bottom of the fuel injector (is there more than one O ring for the fuel injector?)
4) New Screens
5) New Pintle caps
It makes sense to do all 6, but the front 3 are easy. I'll do those soon, but I'm only worried about the back 3 right now. It would really suck if I have a dud in the bunch - any good way to check that?
It would really suck if I have a dud in the bunch - any good way to check that?
If you bought new Hitachi injectors from Rock Auto, the chance of one of them being bad should be slim to none.
The last set of injectors that I bought were $11 each, so I sent them out for testing before I took the time to install. Also, I have replaced the three injectors that are easy to reach, ran them for a week, them moved them to the bank that is under the UIM.
Here's a thread about replacing injectors below. J. Holley mounted the rail to the LIM on his last injector job. That's a good idea as shown on the last post.
This thread provides an example of refurbishing your own injectors using a kit as an example. If you already bought new injectors, you might want to refurbish your old to keep as spares. I do that.
If you decide to refurbish your old injectors, here's a link to a kit for 4 injectors. I could not find the link to 8 that I usually purchase. I like to have a couple of spares. The price for 2 of the 4 kits is less than the amount I paid for 6 a few years ago.
Ok so it looks like all I need are the O rings on these injectors, along with the manifold and EGR gaskets and I should be good.
They come with screens and pintle caps, so it's just the O rings and gaskets.
Seems like everyone is crazy about removing the fuel rail... Is that necessary? I'd like to just swap out the rears in place. I might refurb the three I pull out and then put them up front. Does that really help with the solenoid though? How / why do these fail?
I don't believe in removing the fuel rail. Totally unnecessary. Just be sure the o-rings are lubed properly prior to injector installation.
What kind of lube gives the safest reinsert? Oil, grease from my grease gun, or silicone grease or something else?
Also as you are inserting the injector, do you also lube all friction points in the socket hole?
Thanks! Don't mind me, this seems to be the place where the highest chance of something going afoul.
Also Shrout1, If the engine is out, now would be a good time to do the timing chain, gears, guides and tensioner. Going new will give you another 200K or so and also the engine does get a little quieter.
^I use assembly oil, but any motor oil should suffice. I lightly coat all o-rings, and the injector pops in with virtually no effort or force. No need to worry about friction points in the socket hole; but you could if you wanted to. As I insert, I turn/twist it slightly too. Never had an issue, done this a million times now with great success.
^I use assembly oil, but any motor oil should suffice. I lightly coat all o-rings, and the injector pops in with virtually no effort or force. No need to worry about friction points in the socket hole; but you could if you wanted to. As I insert, I turn/twist it slightly too. Never had an issue, done this a million times now with great success.
Thank you! That helps remove quite a bit of anxiety! I HATE making mistakes.
Also Shrout1, If the engine is out, now would be a good time to do the timing chain, gears, guides and tensioner. Going new will give you another 200K or so and also the engine does get a little quieter.
Yeah I'm with you on that one, but my mechanic pal isn't down for going in that deep. The late model 4th gens supposedly resolved a lot of the timing chain issues... These things are supposed to be good to 300k. We'll see!
If I keep up the rate that I'm driving this it will be 2025 before I hit 250k; crossing my fingers that the timing chain will be good til then. No rattle at 182k and it was nice and tight when I did the water pump.
Back in 2010, I had a couple of Nissan injector coils fail on a 19-year-old Q45 with roughly 115,000 miles. Somehow I think it is more related to age and environmental issues (like heat) over mileage. It happens.
If you like to read about injector diagnostic adventures, here's an old thread from 2010 where I used software to isolate the missing cylinders to confirm suspected failed injector coils. The remaining injectors that were still working were drifting out of spec. So replaced them all and never looked back.
Another thing that is much easier to do while the engine is out, is to clean the EGR system and ungunk the riser tube if you haven't addressed it yet.
If you haven't yet, you're going to be amazed how much tar like gunk resides in there. Like arteries that give a freakin heart attack! LOL
Yep did that! I had a shop vac running while I scraped it out with a hose-loosening tool (like a tiny ice pick). Lotsa gunk in there.
I couldn't push the injectors in by hand... I lubed everything with a little 5-W30 and used the positioning caps (the metal covers that keep the injectors in place) to very, very slowly torque them down (one to two turns of the JIS driver per side at a time). It seemed to work... The engine is back in the bay, but I had to leave on a business trip. Hopefully we'll get the whole thing back together tomorrow.
Fingers crossed you didn't tear or mis-align the o-rings.... Injectors are supposed to 'pop' right in.
Things are smooth so far, I've driven it daily since Saturday. After liberal lubrication with 5w30 on the O-rings I gave the injectors as much force with my fingers as I could; they didn't want to pop in place. I very, very gently tightened them in with the positioning cap.
The first one I did I pulled the cap back off and tugged gently on the injector; it seemed snug in place. During tightening the injector didn't really complain much, it just sort of smoothly slid into place as far as I could tell.
Hopefully this won't cause me any problems! But I don't smell gas and the car is running nice and smooth.
Things are smooth so far, I've driven it daily since Saturday. After liberal lubrication with 5w30 on the O-rings I gave the injectors as much force with my fingers as I could; they didn't want to pop in place. I very, very gently tightened them in with the positioning cap.
The first one I did I pulled the cap back off and tugged gently on the injector; it seemed snug in place. During tightening the injector didn't really complain much, it just sort of smoothly slid into place as far as I could tell.
Hopefully this won't cause me any problems! But I don't smell gas and the car is running nice and smooth.
You got lucky, most people dont check if the injector is actually spraying. I replaced all six this August and two of them were not responding. Thank god i caught that before putting **** back together.
You got lucky, most people dont check if the injector is actually spraying. I replaced all six this August and two of them were not responding. Thank god i caught that before putting **** back together.
Oh man I'm glad you caught that! I was really worried about that happening, so I sprang for the $70 a piece Hitachi OEM injectors. Wasn't cheap, but I figured it would be the best bet for a reliable injector.
I know CS_AR used $11 Chinese injectors and tested them in the front before he swapped them in back. I think he caught a couple bad ones.
Also, I haven't swapped my fronts yet, but the car doesn't seem to be running rough... If the solenoid is dispersing the correct amount of fuel from the old injector then why would there be risk of the engine running unbalanced?
10-23-2017, 10:34 AM
I had a brand new Bosch that the former owner gave me when I bought the car.
LOL
Injectors are supposed to 'pop' right in.
