Mr Goodwrench replaced 2 of the original injectors with Chevy P/N 19244618 last year in my '90 due to abad misfire problem. It fixed the problem but now its starting to misfire again so I'll replace the rest.

This time I'll do it myself as I can't afford $145 x 6 for Chevy's best so my question is do I replace 6 or all 8? Are the GM parts compatible with the aftermarket ones like Bosch? Is there a dimensional problem if I mix them together?

Any brand recommendation or problems would be appreciated.

 

don't mess around with GM replacement injectors, and replace all 8 with an updated design. contact Jon @ FIC - he should be able to fix you up with a cleaned and rebuilt set of boschIII's for very reasonable price - i'm thinking in the neighborhood of 2-bills. a lot of forum have gone this route, and i have on two occasions - both my 90 and 96.

 

What Joe C said.

Put Bosch 3's in 3 years ago & it has not skipped a beat since.

 

I would 1st make sure the misfire is injector related. A lot of things can cause that. Start by checking the plugs and plug wires, distributor cap and rotor. Could be a lot cheaper and easier.

 

Another VERY satisfied FIC customer.

http://www.fuelinjectorconnection.com

 

Thanks guys for the informative replies. Will contact FIC and discuss the requirement with Jon.

As a point of reference the Vert has 44K on the clock. Mr Goodwrench "tuned it up" 500 miles ago to the tune 0f $1500 including the 2 injectors and new plugs.

It only misfires after it warms up much like the original problem that was temporarily fixed with the replacement of the 2 injectors.

 

you're gonna find that the majority of us use Jon, I have a 90 as well and I have Jon's injectors in my car and they are fantastic. If you get stuck, he is a phone call away.

 

me too.....4 yrs. ago....

 

Changing 2 injectors is like changing 1 tire. I have a set from Jon also.

 

Here are a few tips if you do it yourself:
1. Use FIC
2. Good time to replace your valve cover gaskets, EGR valve, plugs, wires, cap and rotor
3. Good time to replace any questionable looking rubber hoses
4. Good time to clean up the runners, plenum and intake manifold and repaint them
5. Get new O rings and replace the old ones in the fuel rails. I was suprised how brittle and nasty mine were. I am suprised there are not more engine fires in aging L98s. This is also a good time to replace the fuel pressure regulator with an aftermarket adjustable one. Spend money for a quality one that comes complete
6. Purchase a FSM (Field Service Manual) so you can see how everything goes together
7. You might want to go a bit farther and remove the intake manifold and reseal it. Put a new thermostat in there too.
Jon at FIC was a real help to me as I could not figure out how to get the little injector retainer clips out of the fuel rail. He explained how to twist them around and said not to reinstall them. He said their purpose was to keep the fuel injectors from falling out during the assembly process. It seems that the fuel rail assembly with injectors would come down from an overhead line. Without the clips installed then gravity would make the injectors fall out.
Great wintertime project. There are a couple of good Youtube "how to" videos out there too.

 

SEND FICINJECTORS A PM HERE

This video might be useful to you as well
Let us know !

 

Test fit into the base. Ain't they purty?

Fuel rail installed. Note that Jon suggests installing them into the fuel rails first and then lowering the injectors into the base. The FSM says to use thread locker on the 4 bolts that hold the assembly to the base.

 

WOW!! I assume the manifold was bright dipped and it shore looks purty with the yellow injectors which I'm guessing are Bosch. Does the Vasilene jar indicate what you used on the O rings?

I'm at the point of getting ready to take out the rails and remove the gas line pressure. It has taken about 6 hours to get to this point as there is a lot more to do than the tutorial shows in the 2 hour out and in.

 

yes put a little on them so that they slide on easier without ripping an o ring.

You must be a twelve packer because you should have been completely done in 6 hours even on your first attempt.

 

You must be a twelve packer because you should have been completely done in 6 hours even on your first attempt.[/QUOTE]

It took a couple of hours to figure out how to get the 13MM wrench that fell under the altenator and wound up between the oil pan and the front cross brace and a 40 torx screw that fell in back of the distributor and wound up on top of the bell housing LOL. Without an LED light at the end of a 10" flexible tube I'd have never even found them.

 

I got this manifold from a friend who had done some porting on it. I cleaned it up real good and sprayed it with a rattle can from Mid America. It was listed as valve cover paint. When I first fired it up the car ran at full throttle! I found out that the manifold was actually from an earlier L98 with a hole for a 9th injector. I had to plug the hole with some JB Weld and a nickel so that it would run properly.
I also installed aftermarket runners and used a die grinder to hog out the plenum so that it would take in more air.
My next mod is to paint the whole intake with black wrinkle finish and use GMPP black valve covers.
Feel free to PM me with questions as I have already made all the dumb mistakes for you in advance!
The car is a Steel Blue Metallic 91 coupe with FX3, A4 and performance rear end.

 

To check the injectors that you think are bad, warm the motor to about normal operating temperature, turn the motor off. Pull the wire off the injector you think is bad, put an electrical ohm tester on the two prongs. You should see about 17 ohms. If you see a reading like 4, 5, or 6 the injector is dying. It will eventually cause the engine to shut down because the ECM doesn't like those numbers.
Two injectors went bad on me in Daytona Beach, bought two there, replaced them in 4 hours, 95 degrees, fired up and got back into the One Lap of America contest 2011.
Then replaced all the injectors with FIC units - they work great. JD

 

Here is a Super Tuneup guide for your L98. Use this guide, do the work yourself and save $1350.

 

ainting or

a great time to do some long overdue maintenance, cleaning and painting and/or powder coating. My wifes C4 after new injectors.

 

Ouch