just buy a new coupling any auto store will have it for a few bucks.

 

Those are the ones I bought, the ones specific to "93 LT1". I'll chat with FIC today.


Guys, it seems every LT1 car I've looked at in the past ran really rich on cold starts. Mine smells so rich on a cold start, that it stinks up the garage and hurts your eyes if you stand behind it. Am I the only obe with that problem? I guess it's due to the 24lb injectors?

 

I searched the forum to see if 93 uses 22 or 24 lb injectors. Most are saying 93's use 22 lb. I do have 24 lb in it, rated at 43.5 PSI. So I called FIC and Jon did not answer. An employee, Jeff, said"93 was a weird year, but they use 24lb" I'm like, really, they use 22 lb. He then said"find a tuner who tune your PCM for the 24lb, or send it to PCM forless". I said no. He said to send him my VIN number, so we can see if my car uses 22 or 24lb. Keep in mind, I've been running 24lb for exactly a year now, on the stock tune, stock engine.

 

Sent him an email with my VIN, and he said "24lb"

 

Hate to look like a dumbazz, I keep updating my thread. He says 24lb. I ohmed my original injectors, still have them, and they all ohm at 12.6 cold
The Bosch III's all ohm at 15-15.2 cold. What do you guys think? The originals had two leakers. Which is why I changed them.

 

Most cars run rich when cold just FYI. My 93 is rich as well and it stinks yes, but I only notice if I start it in the garage or really stand close.

I cannot speak for GM, FIC, or Bosch injectors but the OHM rating of injectors is important.

Case study, my 1991 Nissan pickup was missing on a cylinder intermittent. The spark plug was black and fouled on cyl #1. Too much fuel but ONLY on that cylinder. If I recall the spec in the Nissan manual was 10.5ohms and that #1 injector ohm'ed at 9. I replaced that one injector and the issue was 100% resolved. Had a similar incident on a 93 300ZX (worst car ever to work on) but I fixed it with one new injector. Similar situation a dead miss related to a out of spec injector ohm reading.

Not saying that is your issue but...that is my experience. I mean you figure that ECM is sending out a pulse width that is so many miliseconds long. Power is 12V and the ground is pulsed. If we think about this with basic electrical theory 12V divided by.9 12.6 ohms=.952A for the injector. For the Bosch injectors 12V/15.2=.769A

If the injectors are in parallel, my FSM is NOT handy, the TOTAL circuit resistance would increase with the Bosch's and be lower with the GM injectors. If that is true, then amps are lower for the Bosch's. Not 100% sure how they would react to that but not the same is the point I'm getting at.

FIC, maybe correct, you may need a tune to get them right. The ECM is compensating but apparently not enough.

 

You are not kidding about the Z32 300z's. My dad had a 92 Twin Turbo and wow, made the 95 XJR seem easy to work on

Here's his response, via email.
"hi the driver in that ecu will drive a hi impedance injector from 12 to 18 ohms.. the oem are wet coil and ohm at 12.6 the bosch are dry coils and ohm close to 15 no issue with that at all.. they leak mechanically.. the resistance of the coil is only 1 part of the operation of the injector
jon"

 

Maybe exchange your bosch 3 for a good cleaning/remaining of your originals then no questions asked, then you know they are the proper injector. It's cheaper and they give you the before and after specs according to the website.

 

These are literally brand bew. I changed my fuel filter first, then put these Bosch 3's in. Until then, I won't drive my car. Wanted to take it to Cars&Coffee tomorrow, but oh well.

 

Coupling fixed, or 2 way check valve. Haven't seen what BLM's are now since fixing that. I have a weird thought. If the injectors are indeed to big, why is it only lean on the left bank?

 

In theory then the injectors you have should be fine.

As for the one side being lean and not the other, good question. Exhaust leak on that side? Intake on that side?
Could even be your 02 sensor is a bit off....one way to test that idea is propane. Inject some unlit (duh) propane into your intake and see if the 02's respond with a richer mixture reading and see if it pulls fuel on both sides about equal amounts.

Just an idea.

 

After fixing that coupling, both BLM's get lean on acceleration. WOT, they are both at 128, or pretty near.

No check engine light, but I did scan codes.

Code in module 1: H41

Code in module 4: H26, H42, H67

None in module 9.

For code 41, I'm finding two different things. I fine "loss of ECM serial data communications" also find, "electronic spark timing circuit open". Which is it? Or does code 41 mean both?

Went to go start it just now. Hard starting(temp at 198, if that matters), when it started, the car was misfiring. You could see the LCD light, where it gives your speed, the light was going bright then dimming.

 

How does it run/start cold?

FYI, the BLM's at WOT are meaningless. At WOT the ECM is in open loop mode. It ignores the O2's completely.

It cannot be both, I don't my FSM handy but it cannot be both. If memory serves me correct its the Timing Circuit.

 

Code 41 in module 1 is loss of ecm serial data communications. Essentially you ecm is not responding to the ccm when it tries to communicate. If you get it as a current code You'll be left with a no start condition.

There are two serial data lines that run from the ecm. Could be an issue with the wires being open/shorted or potentially and ecu issue. It seems that 93's suffer from ecu failure more than other years.

 

Runs awesome cold, I'd say perfect. Cold start are right away. 9T3vette is correct, it's ECM related. I checked the FSM. Thanks

 

You are correct. Seems most of threads I was finding was with 93 owners. Should I.check to see if grounds are dirty?

 

I'd suggest following the diagnostic procedure in the FSM, looking for open circuits and shorts to ground between the ecm and ccm. Another thing to check/clean is the main ecu ground wire above the oil filter.
It's really not a big problem until it's a current code, but it could leave you stranded if it pops up at the wrong time.

 

What does it mean to."probe ignition coil module"? How does one check for continuity? I ask because I'm following a diagnostic procedure in the FSM that will tell me if I have a bad ECM connection or bad ECM.

 

Check the small harness between the icm and the opti you can unplug and remove the entire hrness then check both ends for corrosion/wear and continuity between each wire end to end.

 

Hmm, not sure which one that is. When I find it, how do I check for continuity? Sorry, but I don't know how to check for continuity.