Studdering with FMU.....?

**SnakeIs** · 04-08-2003, 09:35 AM

Dan- it went 12.23@115 last season on the stock shortblock right before it blew..... This year I have that DSS in there and still the same cam, heads etc..... I also had the stock EEC in there last year and smaller injectors with the FMU.

**WA2FAST** · 04-08-2003, 12:21 PM

Originally posted by SnakeIs
WA2FAST- that is what scares me, I thought if something was wrong though, that I would get driveability problems or the CE light would have to come on. I had a hell of a time doing that conversion and couldn't for the life of me get that damn red plastic thing back on the harness. But the car fired right up and settled to a nice idle so I figured all was well. I still have the instructions from ProM and there is about 13 pins that you have to change and few wires to add (BAP, Fan control) The car drives great and seems to run smooth so I can't imagine somethings wrong with the conversion.

Okay... well first of all, you NEED to put that red piece back into the harness because that is what locks the pins in place... without it the wires are more than likely making a bad connection or not making one at all (or possibly an intermittent connection... worst case scenario). In either case, you NEED that back in the harness... it shouldn't be hard at all to put back in... that's the other part that scares me... I have done a few of these conversions (a number of MAF conversions as well as 2 of the ones that you did) and never had any trouble with it. Wires are tight, space is tight yes, that is a total pain, but the red "H" should go right back into place with no problems if it was done right. It seems to me like you might have a pin that isn't seated correctly or something. You definitely need to go back and start there first.

If you are hearing (and even feeling through the accelerator pedal) popping (backfiring) through the intake, your car is running WAY too rich... that's what happens when either your car has an abundance of extra fuel or your timing is way off.

**SnakeIs** · 04-08-2003, 01:35 PM

I will try and get that "H" back in soon, I was just worried that I would mess something up by "wiggling" and forcing it in. It seemed as if the wires were kinda tight after doing the conversion because of moving all the pins around.

I don't really have any popping or backfiring at all and the car is pretty smooth, but it still has this hesitation at about 3500rpm up to 4500 or so and then it smoothes out and pulls good to redline. The bottom end of the car feels strong and it blows the tires off rather easily down low it even idles great...thats why I don't think its the EEC. It just seems to "break up" in midrange and the dyno graph even showed it because it was a very rough curve.

**WA2FAST** · 04-08-2003, 03:40 PM

In either case, you need to get that plastic piece back in there. I know that the wires are tight, trust me. The first 94/95 A9L conversion that I did, once it was all done, I actually took the wires back out one by one and un-tangled them from the rest because of how tight it was. You might find doing this (although it is a pain) might be advantageous... troubleshooting bad wires down the line is a MAJOR PITA... I can vouch for that! The red piece is what 'locks' the pins in place in the harness... I know that they clip into place, but after pulling them out and moving them around, they tend to either not clip well or not at all and that is when you start to run into trouble if you don't put that red piece back in... that is my advise to you.

As far as your car is concerned... it is quite obvious that it is running too rich... possibly more rich than any car I have ever seen to be down almost 200rwhp ;) but once you iron it all out and get it back under control, I think you will find some really nice power there with your setup... especially with how the A9L will react to the modifications compared to your stock computer. Please keep us updated as to what you are able to squeeze out of it and any status updates.

**SnakeIs** · 04-09-2003, 06:25 AM

I guess I'll have to take the eec back out and see what I can do....I really don't want to chasing harness problems down the road!

I am going to start by putting my wideband in and then using my tuner to enter the correct Pro M curves for the meter I am using. I played with it last night but the curve seems entirely too rich down low. I am going stay with this though as all the guys on my tuner board say it is the most accurate way to tune. I just have to lean out the curve until I get what the car wants. I don't think I have hurt the motor because it would pull pretty decent up top with the pro m curve in there, so thats a relief. I guess I'll spend the next days/weeks getting this thing right and I'll keep you guys updated. Thanks for the help and suggestions guys!

**paluka21** · 04-09-2003, 08:08 AM

Just a suggestion that you probably don't want to do. However if you cannot get this car straightened out, why not go back to how it was before it started running like this? As in, put the stock EEC back in the car, just to see how it runs. I know its alot of work, however it might help narrow down your issues. Did you get that A9L seated together well?
Since your car went 115mph last year, that is probably evident of at least 375-400rwhp. Does your car feel slower now w/ the new computer?
Just trying to help you figure out whats going on. In all honesty, I do not know why you have to compensate so much to get the car "unrich" or to run decent. In my opinion the car should be on the rich side, but not what its doing, which could also be due to the calibration of the MAF. ( I think I remember you saying you have a calibrated pro-m75 bullet for blow through right? )
As an example, when I first installed the D1SC on my car w/ the stock EEC, I installed MSD 50# injectors, 255 intank, ATI external, kirban 1:1 regulator, pro-m75, plugs gapped at .34, base FP set at 44 with vaccum on, and base timning at 10 degrees. The car actually ran half decent, even with an FMU and the 50's. Granted when the rpms got high, the car would hit a wall due to spark blow out and too much FP. However, when I removed the FMU the car ran stronger and honestly didn't have any issues with driveability, or the car cutting out on me..
hope we are helping at least a little

Dan

**SnakeIs** · 04-09-2003, 10:15 AM

Dan, yes you guys are helping out tremendously! I have actually thought about putting the stock eec back in too, but its such a PITA! I was like 2 days laying on my back on the pass floor board installing that thing, and now everyone seems to like the 94-95 eecs just as much! I am going to keep my head high and try and tune this thing with the A9L but I can tell you I'm getting frustrated as hell... I have had great luck with my car up until this and I'm determined to not let it get me now! Thanks again for the help Dan and Don.

**RI lx** · 04-09-2003, 05:33 PM

If you want to test it without the FMU, just remove the vacumn source and plug it. Without a vacumn/boost source, it won't do anything.

**WA2FAST** · 04-10-2003, 06:14 AM

Yep, he is right... just dissconnect the vacume line and plug it. If the FMU doesn't see boost, it will never effect anything.

**SnakeIs** · 04-10-2003, 06:15 AM

I've already got the FMU off of there and I've been road testing it. It is better but it still feels like it hits a wall at about 4000rpm and just doesnt pull up top like it should. I am in the process of putting the wideband in and I'm going to lean it up until it pulls up top. If this damn weather would just give me a break so I can get under the car.....

**WA2FAST** · 04-10-2003, 06:19 AM

What kind of meter is in the car... you say Pro-M, but which model is it?

**SnakeIs** · 04-10-2003, 08:14 AM

It is the bullet style meter with a 42# calibration Non-supercharged because I was told they make it really rich. It is a blow-thru type also for the ProCharger.

**RI lx** · 04-10-2003, 08:39 AM

Before you go leaning it out, try a .025 plug gap, it sounds like spark blowout to me.

**SnakeIs** · 04-10-2003, 09:59 AM

I'm at .034 now with fairly fresh Motorcraft plugs, not to mention the full MSD ignition (6AL, Coil, Plugs, Wires etc) Do you really think it could be spark?

**paluka21** · 04-10-2003, 11:15 AM

Originally posted by SnakeIs
I'm at .034 now with fairly fresh Motorcraft plugs, not to mention the full MSD ignition (6AL, Coil, Plugs, Wires etc) Do you really think it could be spark?

mine was and I have a full ignition upgrade too.

Mine are gapped at .28, I cant go about .30 with new injectors you are pushing more fuel, maybe drowning out the spark.
did you get that 'puter tightened down?

Dan

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