tenntomt

Both the injectors on my 84 are supplying way too much fuel to the throttle bodies. Is it difficult to replace them and is there anything I need to look out for while replacing them? Also, what 'tells' the injectors how much fuel to send? Thanks...

CFI-EFI

Not difficult to change. The amount of fuel delivered, is a combination of the injector "on time" (pulse width) provided by the ECM and the fuel pressure.

RACE ON!!!

tenntomt

Thanks for the info. I had the ECM replaced about two weeks ago at a local chevy dealer. What a rip off !!!! I hope the one they put in is not defective. The car had been in storage for four years and they claim the ECM was needed to even get the car to run at all. I sure hope I don't have to get a second mortgage to get it where I can drive it. Thanks again. :cry

CFI-EFI

The ECM sends the pulses to the injectors, but it does so, based on feedback from the other sensors. The injectors and the ECM would be the LAST items on MY list of suspects. You DO have a factory service manual...right?

RACE ON!!!

ojaijim

Lets see ... $1800 bucks for the change. Right ! You can get injectors for 2 to 3 hundred bucks. Have the same guy (thats competent) work on your car in your town(if your not doing it your self) . If you continue to go to Chevy/GM for service just sell the car and buy a new one, you'll save money in the long run. Did ya notice the jars of vaseline at the service department ?
Ask questions on this forum It will save you lots of money. :smash:

tenntomt

I just got a repair manual this morning. I sure could have used the vasoline when I left the dealer. They even tried to soak me for a intake gasket, when I got home I found the bolt backed out half way. I am now trying to do the work with the help of a friend. I am replacing the Throttle position sensor, the map sensor and the injectors plus replacing the throttle body gaskets. Thanks to all for the help. :confused:

ben73

Also be sure to check the coolant sensor in the front of the manifold. These are known to go bad, fool the ecm into thinking thatthe motor is cold and therefore causes alot more fuel to be injected.
Check out the oxy sensor also.
Ben.

CFI-EFI

I hope you used your new manual to check all those items you're replacing. It's hard to believe all that stuff is bad. It sounds like you're taking the dealership approace to your home. Good luck, and...

RACE ON!!!

Frizlefrak

Uh huh. Throwing parts at the problem is going to get very pricey in a hurry.....and may not ever make the car run correctly. Better to troubleshoot the problem, and apply the correct repair procedure. Don't let anyone tell you that the Crossfire cars are difficult to work on or that there is something mysterious about your induction system. It's just two TBI systems on one manifold.....the same type of TBI that GM used for years on it's other passenger cars and trucks.

You CAN fix this car yourself and save a bundle. What lead you to fire a cluster salvo of sensors at the car? Did you pull any DTC's (Diagnostic Trouble Codes) from the ECM? Which codes did you get? CFI-EFI is 100% correct....the odds of all those sensors failing simultaneously is......astronomical....it just doesn't happen.

By the way, the aforemention vasoline comment about dealerships is right on the money. These guys will perform financial sodomy on you every chance they get. They invented the phrase "Corvette Tax".

Post your problems here, and we will help you any way we can and will save you a bundle. Performance issues are usually just one simple failed part. Some basic troubleshooting will lead you to which part went on strike.

OH....and as Ben73 suggested...check out that coolant temp switch. If this fails, it will cause a VERY rich condition.


[Modified by Frizlefrak, 10:40 PM 4/27/2004]

silver84

tenn, please tell us which Chevy dealer you had the pleasure of
dealing with.
...
My 84 was not driven for awhile, dead batt,
It took several rides for the ecm to 'relearn' the blm settings.
The other possible problem that jumps to mind is
bad O2 sensor.
An ecm problem, seems like
:bs

tenntomt

I am by no means a mechanic. I am relying on the advice of a friend. I don't have any diagnostic equipment and really don't know how to get diagnostic codes. After retrieving the car from the dealer it was ideling at 15K rpm and nothing we could do would slow it down. We can't find any vacuum leaks and the timing is right on. We were advised to replace the throttle position sensor and the MAP sensor. Both injectors are pouring fuel into the throbble bodies and was advised to replace them also. The car seems to be running smoothly other that the fast idle. :seeya

tenntomt

The dealer was Chuck Graves in Humboldt, Tn. Thats not the end of the story. After ripping me for an ECM and fuel pump they wanted to replace both complete throttle bodies and the intake gasket for a whopping $2300. They said after that there was no guarantee that it would be fixed. I am also positive they loosened the intake bolt to cause the anti freeze leak.

ojaijim

I am not a mechanic ! I can do small simple stuff to my car(like changing the bearings in my headlight motors etc).
I take my car to the same guy all the time (NOT A DEALER). My vette has 206,000 mi. I drive 25000 mi a year in my 89 vert. So I expect problems. I keep my car maintained.
I live in a small town (Ojai Ca) My mechanic wont screw me cause he has to live in the same small town with me ! Find out which mechanic in your town is good and honest. Read and use the forum everyday. I've saved lots of money using the forum.
Good luck !
:auto:

CFI-EFI

You said you bought a manual. Is it a Helms? The factory service manual? You can get one at: http://www.helminc.com Even with out the best manual, a good book will help make a diagnosticion and mechanic out of you. Spend the $50.00 on a decent digital volt-Ohm meter. The purchase of a couple of unnecessary sensors will pay for the meter. Everything else is does for you after that is free. Your buddies/advisors are barking at the moon. Hell, it isn't their money they're wasting. First, check for codes. The book will tell you how. Then follow the trouble shooting charts in the book, to nail down the problem. An out of range sensor reading does NOT mean to automatically replace the offending sensor. GET SMART!

RACE ON!!!

da747

Sears sells voltmeters for 34.99, and on sale are even cheaper. also ive heard autozone sells a little key to jump the ALCL.

rick lambert

Go to this site to learn how to pull codes and what they mean ;) http://www.c4vettes.com/ecm.htm And the guys are right-don't just start throwing in all new parts, and hopefully you've got the Helms manual, if you don't-check ebay :seeya


[Modified by rick lambert, 4:28 PM 4/28/2004]

tenntomt

Looks like I bought the wrong manual I bought Haynes Repair manual I don't see anything in it about diagnostic codes. I went to the web site that shows how to pull the codes. Is there someplace where I can get the definition and actions for the codes or do I need to by the other manual? Thanks for all the input. I'll check the codes.

tenntomt

Thanks Rick for the url for the code definition. I'm definitely on my way. Will check the codes soon as I can. Thanks again...

CFI-EFI

The Haynes is a good start, and we can answer specific questions, like what a specific code means, the the Helms is the only way to go. It covers your year, make and model, only. It has diagnostic charts and problem oriented trouble shooting procedures for your car. Helms is the outfit that Chevy hires to do their manuals. This IS the factory manual. http://www.helminc.com Good luck, and...

RACE ON!!!

Dominic Sorresso

tenntomt,

I have a set of the stock injectors for a Xfire. They were used for only a few thousand miles, before I went to parallel fuel feed and BBC 80# injectors.