I installed new Bosh III fuel injectors today without a hitch. 1 hour taking my time, could probably do it now in a half hour. The fuel filter was the worst dam gas never stops. To be honest I still have the little hick up upon initial acceleration,still has slight miss at idle but when you punch it it seems to have more get up and go.A little disappointed, maybe I had a great set from the factory.

 

Are your new ones the same size as old?

 

yes 24lbs.

 

Not sure how many miles you have put on it since installing the new ones but it might take a little while for the computer to adjust since the flow rate is theoretically the same but in actuality probably slightly different if your old injectors were "really" old (i.e they may have been flowing 22 lbs or whatever and now that you have the new injectors the computer still needs to adjust the block learns).

 

About how long does that usually take, give or take. Thanks

 

Hard to say really, a few hundred miles should do it.

Do you have mods? Could be in the tune.

 

That is one thing the LT1 has over the L98. Easy injector swap. After pulling the injectors on my L98. I noticed a small spring in the top of one of the Accel injectors. So, I'm gonna go ahead and break the fuel rail down and clean it and replace the o-rings.

 

It will start learning new right away if you reset it. Either disconnect the battery or unplug the ECU for a minute or so to clear the memory then reconnect.

You might have a problem beyond that though. My 92 only needs a few minutes or less in closed loop to start altering the BLM figures. This is the "long term" correction figure that the computer uses to "learn" the engine.

Are you able to record data from your computer? It would be helpful if you could read your O2s when you have the problem.

Matt

 

Thank you Matt, I have had a H 64 code, front right side O2 sensor, had some frayed wires, fixed them lost the intermittent service engine light ( came on after highway driving for half an hour ) can't clear H 64 with paper clip method, was wondering if the O2 sensor could cause the hick up upon initial acceleration and slight rough (miss) idle. It is a 95 with 70,000 appears to have not stock plugs and wires so I would assume the opti was changed to. What do you think.

 

what year vette ?

 

If you could do some datalogging then you could see what the sensor is reading and whether your rough idle is occurring in closed loop mode (uses O2 sensors) or open loop mode (no O2 sensors used on cold startup). Get an ALDL cable and some datalogging software. Pretty cheap.

 

95 LT1, a breeze compared to the L98

 

Do you have any idea how much $ and what and where to get it ? Thanks mate

 

I got all mine on-line from Moates.com. All works great. Cable is about $30 I think. Software probably free (tunerpro rt)

 

Have you checked the fuel pressure?

There should be a rise in pressure when the throttle is cracked.

The idle issue can be attributed to spark? Or a soft cylinder?
Did you do a compression check?

BTW the PCM will adjust to the new injectors within the first 5 minutes of driving.

 

Do you think tha the O2 senser issue has nothing to do what is going on?

 

I've got one of those cables as well and use Tunerpro RT.

On my cable when connecting the cable to Tunerpro RT. I have the 10k resistor engaged. Then as soon as the data starts flowing, I turn the resistor off. As having that 10k resistor on can affect RPM's and other things.

 

Josh this technology is over my head I am from old school just getting back into it at 58 . I am from the old rotor and points days when we used to borrow the guy with money who had a timing light we used to adjust carbs by ear no computers,cell phones or TVs, kidding about TVs. So I am kinda lost with this talk.

 

Well Joe, welcome to my world. I had a bad FPR and then decided to replace the whole fuel system so I would know the history of them. As you know I've had an interesting time in all this. Part of the reason I did the whole thing was because of the afore mentioned reason along with having a a weird "stumble" when it went in closed looped.

I had at one time a code 32 (EGR) set so I decided I would just replace the EGR because an EGR can do what mine is doing and what yours is doing. It didn't help it though.

So now there are a couple more things I am going to replace. The ICM, the coil, and the o2 sensors, as all three of these items can be the culprit of what you're describing.

I would like the clerify one thing. I DO NOT believe in throwing parts at an issue. But the reason I don't think twice about this is because I want to know the history of known problem areas and fix them before I get stranded. Once I get these items replaced and it doesn't cure my issue then I'll take it and have it diagnosed by a C4 mech, we have here.


I have read countless threads on this weird stumble issue you and I have and I haven't seen much resolution to it, except for the other day when a memeber changed his egr and his particular problem was solved. And yes he was having an idle issue. But he also had a code 32 set as well, so his was an easy diagnosis and fix.

All I can say is keep working at it and I will as well and maybe, just maybe, someone will pinpoint this issue down.

As a footnote, once I give it throttle the car runs like a champ, it's ONLY at idle.

Also my guess is your injectors were fine, as mine were, so you won't see or feel much of a difference. I know I didn't.

Also it doesn't seem to be just an L98 issue. I've seen the issue with the LT1, so it tells me it is a part somewhere somehow. Compression? maybe but with the low miles you and I have that wouldn't be my first guess.

 

Thanks Mike , I could live with the slight rough idle. The only code I get is the H 64 get and I can't seem to clear it with the paper clip method. This talk of soft cylinder and stuff I then think I am in over my head . mechanic $$$$. Oh well