Well the time has come I guess, I have the injectors gaskets and fuel filter on hand to change out. I have had a warm start issue on this car since April and every one keeps saying it is an injector problem. I have changed plugs, wires, cap, rotor and coil along with fuel pump and filter, ignition coil relays for fuel pump and MAF. None of this has solved the problem so I am about to hang my head low and change the injectors even thou I still do not believe they are the problem. I will be doing this task Saturday afternoon. Hopefully my old schooling from when I had a 76 Firebird will come in handy even thou it was nothing like this engine but atleast the wrench turning will be the same and memory work to try and remember where everything goes back. If any of you have any last words before I start stripping please stand up now or forever hold your peace, LOL

 

Whats the worry?

its well documanted that the stock fuel injector is TRASH and was not designed to be alcohol tolerant. These junk injectors cause all form of engine misbehavior and symptom and cause owners to waste hundreds of dollars chasing problems that are right under thier nose. Thats been so well documented that there are people that have made billions of dollars selling the upgrade Bosch-III injector to most of the C4 community.
Never heard of anyone that had a complaint with the inj upgrade/fix.

maybe it was only millions....

These injectors do a couple things when they die......they will rot internally from the alcohol and the seals inside get destroyed so the spray is poor or non-existent, the coils fail and get weak so the pulsing/cycling is unable to keep pace with the signals that its getting, and last and best, they short out and being a link in a bank fire system they can and often DO cause untold engine damage by flooding with fuel that ends up being GALLONS of raw gas in the oil pan.

Fortunately most folks get the hint when their car gets hard to start or has an ongoing misfire that they cannot fix or explain. A few, like me, had to see raw gas being blown out the exhaust and see an extra 3 qts of liquid on the dipstick....My inj in the #1 hole was actually throwing an arc across to the bracket for the air-pump and leaking fuel from the inj body. I have no idea why it did not catch on fire...I smelled fuel and had the performance problem for days before I could ID the problem. Like most, the injectors was about the last place I looked.

Bank fire...that was a good idea. I suppose it was state of the art at the time.

This is a simple job. Don;t fear it at all. Disassembly is about 30 minutes, pull plenum, TB, d/c injector plugs, pull rails. Set all aside to further disassemble and clean. Put a new section of vac line of the EGR and even pull that to clean the pintle and passage. Your engine will thank you. Do some housework with the plenum and runners off the intake.
You WILL need a coulple extensions and a u-joint for your 3/8 drive to get to some of the runner lower bolts. Don;t miss the 1 on each side thats backwards...that baffles most people. IIRC the driver side rear most is a B**** and takes a series of extensions in 1/4" drive with a joint and some prayer to get to that runner bolt...If you take the dist out you gain some working room.

Use vasoline to install the new O-rings in EVERY pipe joint in the fuel rail. Every one. Same for each O-ring on each injector. Vasoline is preferred because it dissolves instantly when heat is applied and it burns away clean.

When setting the rail back on the 8 injectors, set it on evenly, apply pressure and rock it gently and push until the injectors SNAP into place. This is "setting" the injectors and MUST be done or you WILL have mucho grande leaks. Set both sides of the rail and bolt the 4 rail bolts in place. New o-rings on fuel line fittings...have your flare nut wrench handy or you WILL strip the fuel line nuts. Use a back-up.
AFTER the fuel lines are connected, the rails are SET on the injectors and the regulator is in place,(also cold start if equipped) connect the battery and KEY ON to charge the system. Key ON, OFF, wait 10 seconds and KEY ON again and sniff, look and sniff again for any possible leaks. NOW is the time to discover these very possible fuel leaks when you can easily fix them. DO NOT EVER twist an injector after its been set. This tears the O-ring and it WILL leak. Try to see where each inj should be turned and position it prior to setting the rail.

if no leaks, assemble the runners and plenum. I apply a thin smear of anti-seize to all the intake/runner/TB gaskets so they do not have to be scraped off the aluminum next time. You can use them again if they do not tear apart.

Disassembly...30 min.
cleaning, rail rebuild, injector install...3-4 hrs. Take your time. This is too important to mess up. Use a good dental pick to install o-rings so they do not get cut or torn.
Reassembly of runners & TB...1 hr.

You CAN reassemble with allen bolts if you want to get away from the torx. Many folks do that. The allens are easy to find in metric at any home depot or lowes.
Its a good Saturday job. You will be driving by sunset. First time is always the hardest. After that its cake.
Biggest thing is the O-rings...lube them with vasoline generously and be nice to them..they will hold 40+ psi of gasoline away from your hot exhaust just inches away.

This is not a bad job. I've done it in a parking lot in an afternoon.
Your back may suffer but you will once again enjoy a car that runs right.

Good luck and have fun !

BTW
a FSM set is only $100. Priceless when you have a question in the middle of a job like this.

 

Thanks Lee, that info will be great when Saturday comes to strip them out. Might even take them out Friday after work and then put back together on Saturday do not know if my brain or back can take all this abuse in one day shot. And yah definetly going to find a FSM set soon, as I am sure other problems will surface along the way. My car or should I say the kids car only has 26k on it and runs like a dream once it starts.

Thanks again for the info.

 

26K ? time does more damage to fuel systems than miles.

yeah...injectors. The worst thing for these things is to sit. When they sit with fuel they harden the seals and its pretty much toast. The tiny nozzels get gummed up with hard varnish and the plunger gets blocked. The baskets get plugged...and the injector is suddenly unable to spray and atomize fuel...it dribbles at best.

Heres another tip...roll the car up un ramps or raise it on stands...that gives you enough elevation so you are not bent over as much. Taking a wheel off so you can get in and avoid reaching so far is helpful too.

 

Bag and tag everything and take pictures before you take stuff apart. You can also put masking tape on lines and wires. ("A" tubing goes to "A" port, "B" fitting goes to "B" hole etc.). The bolts for the plenum and runners are 25 ft lbs (if my memory serves me right). Be sure to use new gaskets for them.
It will add to the time and cost involved but this is a great time to install a new intake manifold gasket as they are prone to leak.

 

Couple of pics of my 91:
New Bosch IIIs in place:

Fuel rails installed:

I did the job twice as I did not install new O rings on the fuel rail crossovers. Upon advice from another Forum member I took them apart and put new O rings in as this person warned that there have been several engine compartment fires over the years and that old, dried out O rings were suspected.

 

To add to the fun thats already in store...

if you do not install intake gaskets, its well worth your time to retorque the intake bolts.Check them at least while you have access. They have a habit of coming loose sometimes and thats how the leaks get started. Has to do with aluminum against iron expansion rates and so forth...Not a big deal..just stick the torque wrench on each in the pattern described by GM for torquing the intake.

 

Yessir....

I did that...Took a short cut by installing o-rings everywhere except the regulator pipe..that little thing that just seemed not to be that important...

sho 'nuff 6 months later there is a fuel leak...from the stinkin fuel regulator pipe...the ONLY pipe that I did not disassemble and install a new o-ring....

 

One advantage of being small, I sit on the tires when working on the engine. No back issues.

 

The 88, which mine also is, came with Lucas injectors and they are not junk. They should be black with a green stripe. If you end up replacing them them send me a PM and I'll buy them from you, bad or not.
Ohm your injectors cold and then warm up the car and ohm them hot. If the resistance drops below the lower limit you found your problem. If they ohm good but you still suspect them, remove the fuel rail with the injectors attached.
We keep a spare pump and injector connector for testing. Take a gallon antifreeze container and cut off 1/4 of it opposite the handle. Fill it with just enough fuel to do the job and keep the terminals on the pump out of the fuel. We use a motorcycle battery, you could use your car battery with long leads, and hook the leads to the fuel pump and drop it in the fuel container. Use rubber fuel line to run the supply line to the fuel rail and another from the fuel rail return to the container holding your fuel. Set the fuel rail on something that will not impede the fuel injectors with a catch pan underneath to catch the fuel spraying from the injectors. When everything is ready, connect the hot lead from the pump to the positive battery terminal then just momentarily touch the ground from the pump to the negative battery terminal just long enough to pressurize the fuel rail. Observe your injectors for leaks. If everything looks ok, install your injector connector on each injector one at a time, pressurize the fuel rail, connect the positive lead to the battery and then momentarily touch the ground to the battery and observe you spray pattern. Sounds complicated but it really isnt.
That said, most often it's your 9th cold start injector that leaks or it's spraying fuel on start up even when warm. I disconnected mine.
Since fuel vapors are flammable take every precaution to maintain safety and keep a fire extinguisher on hand.

 

Hi guys, I am in the middle of changeing my injectors, the new/rebuilt ones i have from socal injectors are all yellow. they appear to be a bit shorter then originals and have 2 orings on the bottom that goes into the intake, did i get the wrong ones? they are supposibly bosch 3's urgent reply please.
http://www.ebay.ca/itm/221054260346?...ht_1601wt_1026

 

appers to be the same as I have. mine did not use the clip .what do the directions say?.

 

no directions with them unfortunately, and now the seal for cold start injector is wrecked so at a stand still for now

 

I recall that the Bosh were slightly shorter -or longer, can't recall, because of no-clip design. I ignored it since it was supposed to be by design. most likely they are identical to mine, from the picture. don't have the cold start but the seal is just an o ring from what I have seen.

mellow out, Mark. enjoy the experience! you are probably Ok.

joe

*** the height of injectors is not critical, I think, since they are free to rotete somewhat. as long as the seals are within the sockets they should seal with no leaks.

 

Cannot find o-ring or gasket for cold start injector fuel line does any one know what size of plug i need to plug off fuel rail.

 

Mark found my tech sheet from FIC. the Bosch III do not use clips, are 1/4 shorter than multecs. they install in intake first, rail is lowered and positioned over them, not so hard to do.
there is a start up procedure if you want it.
or, www.thirdgen.org/injectorswap.

no help on the cold start inj. leesvette might know.

joe

 

Thanks for the help guys. Injectors are installed and car starts great during the day time. First start of the day is a bit trouble some as I plugged of the cold start at fuel rail for now till I can locate a new fitting and seal, or might just leave it unhooked as I am not using the car in cold weather anyways. Is it normal to see the second o-ring on the intake a bit like maybe a 1/32 of it. And by the way for all those that said it was my injectors causing my warm start problems I bow to you and say you were correct and hate to say it but I was wrong. But atleast I have alot of new parts on the car now, lol.