C4 1989 Fuel Injector Question

[Justin B.]

I have found out that the fuel injectors on #5,6,7 cylinders are not working. Do I have to remove the runners and plenum to remove these injectors? Is there by-any-chance a solenoid or sensor that would cause these to not work?

[George D.]

Re: C4 1989 Fuel Injector Question

Justin,

I had a similar problem with my L98 90 and only the bad one replaced by a dealer while I was at Carlisle. Shortly after another one went bad whille on my way to having the car judged at the nationals in Boston. If the injectors are the original I would suggest replacing them all. Otherwise, you'll be doing the job again. Not a complicated fix, just time consuming and costly. Worst part was getting a couple of th torx head screws out of the runners. Also, did you check the resistance on all of the injector to be sure that is what the problem is?

[Clem Z.]

Re: C4 1989 Fuel Injector Question

if these injectors are fuel cooled i have heard that the ethanol in the gasoline now days attacks the insulation on the coils.

[James W.]

Re: C4 1989 Fuel Injector Question

Justin,

I have a 90 ZR-1 and went through the same thing. You have wet coil injectors and the ethanol fries them. Contact Jon Banner at fuelinjectionconnection.com and he can fix you up with Dephi injectors that are dry coil. He did mine and he is very good to work with. I did not flush out my fuel rails when I originally changed mine out and one gotta piece of dirt in it. He sent me a new set at no charge

Jim

[Walter G.]

Re: C4 1989 Fuel Injector Question

I had a problem with my '89 in about '94 after returning from Bloomington Gold and getting some ethanol gas in IA. Long story short, the dealer replaced all the injectors to the tune of about $900. GM came through and refunded me $500 and the dealership kicked in another $200 so I didn't come out too bad. The car had only 12,000 miles at the time, and GM said the original injectors were not "ethanol resistant". Apparently many Cavaliers of the era were the first to experience the problem and other models followed. That car has been gone for a few years or I would have had the paperwork with part #'s for the replacements which worked fine for the next three years.

[William C.]

Re: C4 1989 Fuel Injector Question

My 5 star bowtie has all new injectors now after stranding me on the road. The originals use the fuel to cool the coil that fires the pintle in the injector. That nasty alcohol-laced fuel we have today just eats the insulation right up. Had one fail on the road, learned a lot about the problem and replaced the entire set. Not a real bug job, Have to pull the fuel rails but not the plenum as I recall.

[Justin B.]

Re: C4 1989 Fuel Injector Question

George, how do I check the resistance?

[William C.]

Re: C4 1989 Fuel Injector Question

Pull the injector electrical connector off at the injector and use an Ohmeter to check the resistance, should be similar among all the injectors +/- 10% a shorted one will be obvious

[Wayne W.]

Re: C4 1989 Fuel Injector Question

This has become a very common problem with the ethanol fuel, and some on here and other forums will defend to the death that ethanol has caused no problems. BS there have been a lot of problems and cost to the driving public. But we have to live with it, so changing out a few things is essential to keep them running.

The ohm reading on these injectors should be about 16-17 ohms. If you find one or two that are less, 12 or so, the car will run OK, but miss at idle. That is usually the first thing you notice. If one or two short out, the computer shuts down. It will probably start again after it cools off, but will not go far without doing it again. Replacing one injector at a time is useless, and expensive. If you get The General to do it for you, you will never need another hemorrhoid operation. A set of new, dry coil, ethanol proof, injectors can be had for about $200 set, $300 if you want them to look original. Labor should be 1-3 hours depending on what you run in to.

[Jim T.]

Re: C4 1989 Fuel Injector Question

Wayne my 1985 still has it's original factory fuel injectors. What brand name injectors do you recommend that are dry coil and ethanol proof? I have not checked the ohms on the 85's injectors. How do you check the ohms?

[Bill H.]

Re: C4 1989 Fuel Injector Question

Wayne my 1985 still has it's original factory fuel injectors. What brand name injectors do you recommend that are dry coil and ethanol proof? I have not checked the ohms on the 85's injectors. How do you check the ohms?

James mentioned calling Jon at FIC. I'll second that, a lot of guys on our C4 forum have purchased injectors from him, the prices & service are unbeatable.
You can take a look at their Corvette injectors at corvetteinjectors.com but I'd call them to discuss specifics.

[Wayne W.]

Re: C4 1989 Fuel Injector Question

Pull the wire connectors off the injector by squeezing the spring clip. There are two terminals on the injector. Check the ohm value across the two terminals.

Most of the time I use the Bosh. They look different though.

[Joe L.]

Re: C4 1989 Fuel Injector Question

All------


The 85-91 injectors were manufactured by Bosch, Lucas, or Delco, depending upon the year. The 92-96 injectors I believe were all of Delco design and manufacture. Does anyone know if these apparently ethanol-related injector problems afflict the 92-96 injectors?

[Vinnie P.]

Re: C4 1989 Fuel Injector Question

Justin...the Winter 2012 issue of The Restorer has an article on replacing the injectors...page 20-22...if you would like a pdf of the artlcle, let me know

[Patrick N.]

Re: C4 1989 Fuel Injector Question

To add, my 88 had 4 injectors fail from day one. They were replaced under warranty back in 90 and are still in the car today. TSB 04-06-04-051B JAN 06 Fuel System - Fuel Injector Maintenance Cleaning was later issued but not sure if this to address the failures experienced early on?

Regarding Ethanol, under the right conditions it WILL effect metal materials and elastomers. Ethanol and bio-diesel are solvents, both are more conductive than gas, especially if water is added leading to galvanic corrosion in the right conditions . Ethanol is notorious for phase separation with as little as 0.5% water, the water will collect on the bottom of a tank. Some materials like Viton (A or GBL) will both swell and suffer loss of tensile strength (up to 50% loss) which does not occur when Viton is in contact with gas. There is more to the polarity of Ethanol being all good or all bad. Certain conditions must be present for failure, but these conditions are not that hard to encounter. These problems are also most common in dynamic gaskets vs. static gaskets.



Pat