Interesting, can ECM have an internal over current detector for injectors?

ECM’s internal injector drivers can detect a short or open circuit
and close down injector pulsing immediate whiteout setting an error code??

Kjell

 

How many miles do you have on the car? Are these original injectors?

The ECM on an 89 will close down the entire bank if it detects an error putting the car into "limp home" mode. Last year I had an injector in each bank go bad so the whole engine wouldn't fire. Took forever trouble shooting because the car just wouldn't run long enough to pull the codes.

Know earlier post suggested forcing the ECM into "limp home" mode.

Good luck with the weekend injector replacement.

 

The car has over 230,000 miles! Yep -I assume they are the original injectors (i've only owned the car for about 10~years or more).

There is nothing wrong with any of engine sensors, voltages, circuits, modules, fuses or fuel pump/lines/filters/regulator/pressure - all have been test on and off the car. I tried the 3.9 resitor across the "a & B" test-nice trick - but didn't work for my problem. There are no opens, shorted or grounding issues with the circuit in the car either. I have no-none-zero amount of fuel delivered from either bank or individual injectors when ECM controls the grounding of the INJ circuit. The ECM has been proven to pulsing the injectors at a width of 128 per second while engine runs off of the ether spray. There is just simply no fuel delivery.

As far a detecting high current the injectors have 10 & 20 amp fues for the purpose of interupting "hard" shorted coils.

The ECM has no way of knowing the amount of fuel that is "actually" delivered - it only sees the feedback of the oxygen sensor, rpm, MAT, coolant temp and MAF to tell it to increase or degrease the fuel pulse widths. In my senerio these signals are generated/satisfied by getting fuel from the use of ether spray - so the engine runs with no gas from the injectors.

 

230,000 on Multitec injectors?? You may have set the record. Mine crapped out at 45,000.

Surprised you haven't upgraded them after seeing all the horror stories posted here. I believe you'll definitely see improved performance.

 

OK so I got the fuel injectors in the mail today about noon(I guess second day priority mail takes 3 days)....ate some lunch.....got them installed on the car at about 5pm. The car cranked right up! GO FIGURE!

The Ford lifters are kinda loud though - but I don't mind 'cause it runs.

Thanks for all the help people!



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all "bad" at once...i dont believe it!....congrats!

 

Glad to hear it have you noticed a performance increase with the new ones over the way it was running before?

 

I still have to fine tune the timing....when that's done I'll stomp on the gas and see if there is any performance differences.

Here is a picture of a couple of "old" injectors that I removed....the 6 out of the 8 look like crap on the fuel rail side.....I'm sure the insides of the injectors look the same.

 

Glad to hear she is back up and running!!!!!

 

Congrats. It makes sense. You were getting signal to the injectors and the engine would start with starting fluid. The injectors were just not spraying.

 

Engle,

Your tenacity and sticktoitVNESS is absolutely impressive. I almost want to finance you opening up an early C4 repair facility. You certainly seem to like doing this :-) Great Work. I've been following this thread and am simply amazed that you just didn't give up and get rid of the vette along the way.... You definitley picked up an incredible amount of knowledge along the way. Kudos man! BTW, The helms FSM can be had on ebay for about 30 bucks if you're lucky. http://cgi.ebay.com/ebaymotors/1986-...spagenameZWDVW Send me your email and I'll send you an electronic version in pdf format. leefarah@yahoo.com

 

Not an injector guru but I had 2 bad ones last year, one in each bank. The computer detected a bad injector and shut the bank down, and then detected the second faulty injector and shut the other bank down. Car would refire in 3-4 hours so trouble shooting was a b#$%h. After replacing all eight the car ran fine, replaced the burnoff relay also.

 

check your cts (coolant temp sensor) and wiring up to the ecm. the ecm uses this signal to operate other sensors etc. turn your ignition to run position. check the digital temp. it should be close to what the weather is outside. my 92 had a lose connection going into ecm and every once in a while it would not start. my digital temp would read 142 every once in a while, even after it was warmed up. it is the yellow wire in the green connector. it is worth a try

 

Have you considered checking your VATS system?
My 1988 35th anniversary edition this year gave me a problem with running and then suddenly I couldn't start it. I ended up flatbedding it , only to go out to the garage a few days later and have her start right up. I contemplated taking her out for a spin, so I first turned her off, then bam she did it again and wouldn't start. Did some reading on the 'net and I am pretty sure the VATS is giving me an intermittent problem, so I am going to bypass it with a resistor. Do you see the orange "security" light flashing when you attempt to start? If so it looks like you can bet that your VATS is giving you a problem, could be as simple as the contacts in the key cylinder are worn out. For me I know my cylinder contacts are not worn out, the car barely has 8,000 miles on it, not enough use to wear out yet, they might be tarnished if anything.
Here is a link to the bypass procedure: http://www.stolenandrecovered.com/VATS.pdf

 

i had a bad misfire problem with my 90 and replaced the wires and plugs and still had the problem. i didnt have the money to buy new injectors at the time so i unbolted the fuel line and fuel rail and lifted the injectors up enough to see if any werent firing. when i had the ignition on one of the injectors was constantly firing and when i tried to start, 2 others wouldnt fire at all. if i would have just sat with the key on for a while and then started it i could have thrown a rod. free way to check em. hopefully someone finds it useful.