i had just swapped a 86 305 tpi into my 79 malobu / a 350 now i think its running too lean because the headers were glowing red .it was very hard to start .my friend can do a little chip programming and i heard a little about injector constant .can anyone give me a little more info .also i have gotten 22# injectors from a vette. im getting very frustratedplease help me??

 

First, check your fuel pressure- while driving. You'll need to rig up a gauge that you can see while driving it. The pressure should not drop below 30 psi even at WOT.

Also make sure you have the fuel filter oriented properly. Often times the high pressure filters are directional.

Make sure your O2 sensor is hooked up- and corectly.

If you can get a hold of a scanner, it'll tell you alot about what the computer is seeing.

 

no filter yet and pressure is ok am still in the middle of swap .i cant even get it to idle .im also breaking in a new cam so i cant let it idle too long.also o2 is hooked up and ok

 

Make sure your timing is correct. Also, your balancer could have slipped....mine did. My timing mark was off 35 degrees. I replaced it today, actually, to fix the problem you are describing. Find TDC by a method other than looking at the balancer, and then see where the timing mark is. Like I said, mine was WAY off - I was shocked. Should be good now...so check yours too.

 

where in my chip program can i change the fi constant and where about should the value be?let me rephrase the first subject , it barely runs, alot of backfiring, extremely hard to start and keep running i have to floor it to keep it running and it is very irratic

 

Are you running the 22# injectors now are you using the ones that came with the setup? If you aren't using the 22# injectors then you need to. 19# injectors are too small for a 350 unless you crank the pressure way up.
I would agree with others that your timing is probably waaayyy off. Pull the distributor out, rotate it 180º and then drop it back in and see if that helps.

 

i finally got my car running the timing was way off. but after it runs it wont start again till an hour or so later. would my engine even run if the distributor was 180' off. its driving me crazy that i cant drive it after all this work i put into it. when it runs it runs pretty good but it just sputters when i try to start it again. also my oil smells like gas is that too rich or just from cranking it a million times????????i do have the 22# injectors . do i have to change any computer settings since it was originally for a 305? also i just read this my fuel pressure is ok but it leaks down slowly

 

If the ECM thinks you have 19 lb injs, it will leave the 22 lb injs open too long.

Sounds like the inj constant needs to be changed on the chip and the inj/s may be leaking after eng shutdown, flooding eng.

The fuel press, at shutdown, should hold steady for a couple of mins at least.

You really need to interface with the ECM to see whats going on.
BLMs, INTs, etc..

 

whats blm & int

 

i tried to replace the ignition module ....that didnt work.i unhooked the MAF ...that didnt work . i rotated the distributor ....that didnt work. the engine starts up fine in the morning and will run till whenever .but as soon as i shut it down it wont start for nothing it just cranks. im using gmecmedit but i dont see the injector constant theat needs to be changed. ive found crank fuel PW vs coolant temp is that it. the plugs are dry after it runs even after crankin for a while

 

The constants are "Single fire FI size @ 40 PSI" and "Double fire FI size @40 psi". Try setting them to the size injectors you have. Set them both to the same #.

BLM is knid of hard to explain.
The BLM indicates how much the computer is altering the pulse width to the injectors. 128 is perfect. If it's higher then 128, the computer is having to add more fuel than it thinks it should need to. Lower than 128, it's taking Pulse width (fuel) away.
INT is kinda the same but it's making quick changes where the BLM is making long term changes.

If the BLMs are at their limit of 108 or 160, the computer is on the edge (or past the edge) of not being able to compensate enough to keep the O2 sensor happy.

If say the BLMs are lower then 128 while at cruise, you'll need to change the FI constants (mentioned above) to a larger value. Reason being if the computer think the injs are larger, it won't leave them open as long.

Once you get the BLMs between 124 and 132, that's close enough for most folks.

BLMs (and INTs) are meaningless if ECM is in open loop or at WOT (which forces open loop).

Hopefully this hasn't confused you more. Its a bit funky at first, but gets easier the more you learn abt it.

I'd make sure the fuel press is all good before messing with the chip.

 

thanx alot this is the most info ive gotten yet . i get it now its block learn and i forget the other one but yeah short term changes and long term changes. also making it leaner if rich and vice versa. cool this will give me what i need to change i hope for now. more advice is still welcome