The engine seems to smooth out as rpm's climb. by 2000rpm, it feels OK; 3000+ it feels pretty normal. It does not "cut out" or fall on it's face @ high RPM.

Dave

 

Does it seem to cut out more or less at idle after you revved it those few times? What has your fuel mileage done, go up or down? Have you ever used datamaster? Its another scanning program. What has been the progression of the problem as you replaced parts? Did it change at all with the new injectors (ie less stumbling, more stumbling, different rpms, etc)?

Jonota

 

It seems to cut out about the same after revving @ idle. I do get little exhaust "pops" as revs fall.

The first things I did were the plugs and wires and pulled the IAC and cleaned it. I did the coil next. All to no effect. There had been absolutely no change in the problem until I put in the new injectors. Now the car runs fairly rough sometimes; usually when fully warm, but other days it seems to run pretty good. I've only been through about a half a tank of gas since putting in the injectors, but it looks like my mileage is lower. I used to see 14-15mpg around town, and this week it seems like 12-13. Performance seems down since the injectors too. Before, the problem was a miss every few seconds(@ idle), most noticeable when idling. Now it seems like it just runs rough, and has a pretty good shake 800-2000rpms, but not all the time.(Under the same conditions) It still pulls hard to 5500 though, and doesn't get worse under load.

I hope I'm being clear, if not ask me to explain it again.

I have not used Datamaster. This is my first foray into FI cars, so i'm just getting my feet wet. I'm used to turning carb screws and replacing jets... I found freescan and pcmread/pcmcomm as freeware. I'm thinking of getting LT1 edit, but first I really wanted to get these driveability problems out of the way.

Did you get that .LT1 file? Does it look stock, or has someone already been in there?

Dave

 

I got it, but haven't had time to look at it yet. I will let you know tonight or tomorrow. I personally like Tunercats over LT1edit... but that's just my opinion.

Jonota

 

I didn't get a chance to look very thoroughly, but from what I can tell you have a stock program. I am currently searching for specifics on changing the injectors. If I recall correctly, you will need to change the PCM's idea of how much the injectors flow for 3 different reasons: because they are higher than stock rating (24vs26), they are a different style (accel is pintle style, which flows better than stock), and they may be rated at 26 lb/hr at a different fuel pressure than stock. I will let you know what I find... you can do some research yourself as well..

Jonota

 

Jonota,

That makes sense. I will surf around and see if I can find out any specifics about flow rate vs. fuel psi. I know that the Accel's are 26# @ 43.5 psi.

I did drive around yesterday with the comp. hooked up and I noticed that BLM's are much closer to 128 in both cells 16 and 17. If i remember right they were ~140 a week ago.

I also picked up a set of o2's, and am going to throw those in today. From what I can tell, the car has the originals in it. 80,000 miles, I figure they should be done just as a maintenance item, even though they seem to be operating OK. While I'm under the car I will also check out the plugs and wires to see if I can find something there.

Why do you prefer tunercats over LT1Edit? I have no expirience with either, so I'd be interested in your opinion...


Dave

 

I guess price would be one factor, another would be it seems very simple to me. I was able to pick up how to do just about anything, and the help files were very direct. I had a LOT of customer support from TC, as well as Andrew Mattei from AKM cables. That kinda hooked me. Also, Tunercats gives you a free 30 day trial!

Jonota

 

OK so I put the new O2's in.... no change, but I hadn't really expected there to be. I also pulled the wires and checked them out, they are all ok. I am going to pull the plugs and do a compression test soon I think... Anyways...


Jonota, have you found out anything about programming for the Accell injectors? I surfed around and all I could find out was some people on an Impala board saying they flow about 15% more than stock, due to pintle design.

Dave

 

Where did you get your flow #'s for the injectors from? I read somewhere that the Ford/SVO/Accels were flow rated at 39psi fuel pressure. You should call Accel and find out exactly what they are rated. If the injectors that you have do indeed flow 15% more, that could very well be your problem. I believe no more than around 5% can be changed without a good reprogram.

Jonota