30 lb injector woes

93lxtwin

93lxtwin

New Member
Apr 16, 2009
37
0
0
Wilmington, NC
#1
Whats up everyone. Got some tuning issues and wonder if anyone has any advice. First things first, a list of what has been done so far. 1993 lx, block bored .030, crank turned .010. Trick flow track heat combo installed on top end. 190 lph fuel pump. Msd distributor (no box, plug and play). 75mm throttle body. Egr spacer. Cold air intake. Recently had to replace the ECM, just quit on me one day. Put an A9L in the car, came with a hypertech chip installed. I have no idea as to what program has been burned on it. I removed the chip for the time being. So i have been running the stock injectors up until yesterday. I ordered 30 lb Ford Racing injectors and a C&L 76mm MAF. Installed this stuff yesterday, car ran like s@#t. Had to undo everything today just so i could drive it. Im sure it mostly is because of the ecm programming, nowhere near capable to handle those injectors. i was hoping that installing the chip back on to the ecm, might help. It didnt. Car was surging and backfiring through the intake. I tried messing with the timing to no avail. Does anyone know how to find out what program is on a hypertech chip without having to go to a dyno? And any other tuning help with this set up would be much appreciated.
 
#3
Yes it appears to be. It has the tube inside of it. I had to install my factory sensor on it. From everything i have read on the forum here, that is ok as far as the sensor is concerned. Like i said, im pretty sure most of the problem is in the ecm program along with the hypertech chip. Its just weird how what ive been reading says that if i was using 24 lb injectors with a calibrated maf, it should work just fine on the stock computer, a9l, i could just be reading those threads wrong. Im starting to wonder if i shouldnt have bought the 30 lbs and just have bought 24 lbs instead. Thanks again for any input.
 
#5
You will learn that C&L sucks..C&L meters utilize your factory mass air sensor, so in a nutshell the C&L is almost in since lying to your ecm about the amount of airflow being delivered. Having said that, you SHOULD be able to at least be able to make it driveable.. Im guessing your C&L is not calibrated for your 30lb injectors, all C&L does to calibrate there meters is supply different diameter tubes, make sure your tube diameter is correct!!
 
#6
What color is the sample tube inside the meter? for 30 lbers it should be red. I beleive 24s are blue and 19s are not colored. I have the same 30 lb injector with C&L meter setup and the stock computer doesn't mind at all, even with heads, a cam and very high compression
 
#7
The tube has red coloring on it. The guy i bought them off of on EBAY, said they ran fine on his set up with a stock computer, but he was switching to a big block and had no need for them anymore. I'm kinda stuck as to what to do. When it was running like crap and surging, if i created a vaccum leak, it would actually smooth out a little. Like it wasnt getting enough air. Also i'm only running the stock fuel pressure regulator for now. Thanks again for all the input.
 
#9
I would take it you are using the maf as a blow thru? well you may need to clock (turn) the maf to get the air drawn across your sample tube.. I had lots of problems with c$l but you can get it to run pretty well by clocking it... you are probably having alot of air bypass your sample tube... try putting some lube on the ends of the maf and installing it then leave the clamps loose enough to where you can turn the maf... start the car and rotate it till you get the car too smooth out... then go to far to where it runs bad and put it in the middle of those two areas... as stated the maf is tricking the ecm via the sample tube... you can get a maf turned for the 30s that doesn't do anything for you high and low slopes or your carnking pulse widths... you may want to break down and by a tuner like the tweecer or moates quarterhorse... both of these have a large learning curve but there is great support out the via forums ....I now run a Pro m maf with a universal sensor and tune the computer to it.. makes a big differnce, but you should do fine with what you have just clock it and see what happens...

simon
 
#10
one other note... I noticed you have are running stock fuel pressure well that is okay for... but what a lot of people don't realize that you should actually drop you fuel pressure down with a bigger injector... I am about to install 60;s on my set up now with the 42s I run about 27lbs of pressure ... again all that goes along with really getting a good tune and using a tuner... good luck hope this helps
 
#11
atichargr said:
one other note... I noticed you have are running stock fuel pressure well that is okay for... but what a lot of people don't realize that you should actually drop you fuel pressure down with a bigger injector... I am about to install 60;s on my set up now with the 42s I run about 27lbs of pressure ... again all that goes along with really getting a good tune and using a tuner... good luck hope this helps
Click to expand...

You should not have to change fuel pressure once you get it professionally tuned which is what I recommend the OP get done , he needs to find a tuner to take the car to and have it tuned with a chip the proper way , not all setups are going to run correctly with just bigger injectors and a calibrated MAF , it all depends on the air flow of the setup and how good the meter is calibrated , C&L are not any worse or better than any other brand of calibrated meter , they are all a hack job way of tuning the car because 10 years ago tuning with a chip was still voodoo to most people which is not the case anymore
 
#12
one thing is for sure.... i had a c&L meter for my 42s and 24s and my car did the exact same thing... didnt know what to do.. so i would change everything and still nada.... my friend came over and switch computers and still same problem.. we redid timming, fuel pressure, clean the tank out, change fuel filter, etc.. finally we switched his promass meter with my C&L and there is was:D.. C&L are not the way to go
 
#13
Thanks Torch, I wish I could swap out parts with a buddy, unfortunatly, I work at an import shop, and most of my friends drive imports. So no luck for me there. It seems I'm alone in my principles of thinking the Mustang is one of, if not the best cars ever made that a person can buy and drive, or modify the hell out of and have alot of fun doing it. At least I'm alone in thinking that at the shop I work at. Lol. But thanks to everyone for all of your ideas. I'm gonna keep messing with her when I can, I have to order some more stuff soon, including an adjustable fuel pressure regulator, among other things. And then I'll give the clocking idea a go and see what happens. If nothing else, I'll be no worse off than I was the other day. Then I'll just save the pennies for a professional tune. Now all I have to do is find someone repuatable around Wilmington N.C. that knows what they're doing to do it!:shrug:
 
#14
So I've been wondering, what is everyone's take on stand alone fuel management systems? No good for Mustangs or what? I know all my friends running modded motors and boost on their imports have them and are able to dial there fuel settings in pretty easily. Do these setups work well on our fox bodies? Thanks for the input as always.
 
#15
I don't know about a stand alone , but the only problem is the major part of any tune is getting the maf curve tuned in at which point your a/f ration will follow... if you want to do some tuning I would recommend a tweecer or a quarterhorse... the quarterhorse is cheaper in price I havn't used one but from what I hear is just as good as a tweecer... I use a tweecer and am about to try a quarterhorse.. adjusting your fuel won't help if your maf curve is not correct.. you may set your a/f ration at idle and fine that it idles well but drives like crap.. just my 2 cents
 
#16
Makes perfect sense. What is a quarterhorse and tweecer? Forgive my ignorance on this issue. I've never heard of them before or what they do. Last mustang I had before this was a 66 and was carbed. Thanks for all of this advice, it really helps me to figure out what the heck is going on.
 
#18
the quarterhorse is a little nicer since you actually put it in the computer where as the tweecer you attatch to the j3 port on the back of the computer... which makes it a little harder to put it back up behind the kick panel... put basically the are tuners that you can adjust almost every perameter of the computer... I use the tweecer now but am about to change to the quarterhorse...
 
#19
Thanks for the info. Does anyone know what the 8 little switches on a Hypertech chip are for? I can't seem to find any information on this, nor can I find out how to tell what program has been burned on the chip. Switch number 7 is in the up position on my chip and all the other ones are down. Just curious to know what they are for.
 
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