I'm haven problems with my trucks ecm so here's the deal I put a new cam in my truck exact same grind as the one that was in it so before the cam swap I'd get a code 13 once in a while now with the new cam at first when the check engine light would come on, I'd pull the codes and all I got was 12(ecm working) but now I'm getting 44 and it runs like shicks It wont build any power I'ts almost acting like I'm not getting any spark advance from the distributer or to much fuel
both codes are 02 codes whats the diferance in them

and let me trow this out there I'm getting good fuel milage but when I get on it I can see the black smoke from my tail pipes

Code 44 is lean exhaust, system might be richening up the mixture trying to overcome it whether it's actually lean or not, the result is the same. Also the system should go open loop at wide-open-throttle (WOT) so the mixture will go rich then anyway, that is normal, but if it was already a little rich that's why you're seeing it smoke black.

You replaced the cam with the same exact grind because your old one went bad? Wiped out a lobe or smth? You installed the cam in the exact same position, not retarded or advanced? You set and double-check your base timing already? What is it set at... and what year, model, engine?

Richard

THis kinda stuff is why I am affraid to do the heads and cam on my truck. I dont want it worse than it already is.

its an 88 crew cab with the 454
yea the cam went flat and the new one was set the same as last time the timing is set at 8' btc

let me ask this is their any thing in the distributor that move to advance the timing or is it all done in the electronics because I'm woundering if the timing not advancing under a load

the distributor is about the only thing that I havent toar into to make changes for the better other then a MSD cap and rotor

What cam did you goto?

I've got an isky hyd cam its 262' duration and 488 lift its not real big but it keeps a good vacum signal

bump

Could it be some crap from the last cam causing issues? I guess you would get issues at idle. have you tried moving the timming around?

There's no vacuum or mechanical advance on the distributor, it's all electronic. Though there's two ways it advances the timing. One is the computer will advance the timing when the ESC module is working as it should, if you're familiar with unplugging that tan wire w/the black stripe before setting your base timing, that's the ESC module you are disabling so that you can get a steady timing reading without the ESC module advancing it. In a way, think of this just like on a carburetor engine, unhooking the vacuum advance and plugging the hose before you set the timing, then you hook it back up after.

The other way is the ignition module itself has a default advance curve built into it, that sort of mimics mechanical advance in the older distributors. Even with the ESC module disabled, as you rev it up, it will advance the timing a little bit.

If your base timing is off, or the ESC module tan/black wire disconnected, or ignition module going bad...you can have problems with the advance.

Richard

nope! I think I got it figured out

when I was getting all the parts together to put the cam in I ordered the victor nitrseal intake gaskets being that I couldn't get them with the heat risers cut out . I thought I'd just cut them out (and you think you know where this is going? wrong!) i didn't forget to cut them out! In my quest for a little more horse power the thought was if I leave the heat risers blocked it will keep the intake alittle cooler( = more power) well the ECM dosnt like the EGR valve not working! (mental note made to self) Soooo..... in my pissed off twisted state that I was in to replace the intake gaskets I didnt let the truck warm up enough to open the thermostat before I put the rad cap on tight it. so here's my theory, it developed an air pocket under the coolent temp switch that made the ECM think it was running cold, making it run in open loop and flooding it out when I'd give it throttle

I was out playing around with it and I noticed that the rad cap was leaking so I went and got a new one and for some resone I left it running while I went to the parts store and topped off the water when I replaced the cap so when I took it over to the store tonight it sure ran better so I went for a little drive and it was able to go up hill and do 80+ on the freeway in a short distance I still have some tune'n issuse to work out but I think I can drive it now

Yeah in my experience temperature sensors (including the ones for the gauge) don't work unless the liquid is touching them.

So it's acting better now?

As far as air pockets I usually drill a few small holes in the flat part of the thermostat to bleed air.

Richard

yeah lets hear the update pig?

well thats wasn't the magical cure it ran good for a couple days now its running worse but it only does it once its warmed up and im getting code 44 witch is a lean o2

heres what its doing once it warms up and your cruzing down the freeway at lets say 70mph I hit a small incline in the road and you give it a little gas to keep your speed up it goes flat like its being choked and starts loosing speed by the time you make that small incline your speed is about 60 and you cant get it to speed back up once your on the flat. but to day i cant hardly give it gas in revers with out it chokeing out

with these long hours that I'm working I don't have time to work on it but I need to drive it so I can have my tools at work

Have you checked your fuel pressure yet...T into the line at the filter and run a long hose on the gauge, hang it under your wiper arm, be sure you clamp everything up so it's not gonna leak or come off. Go for a drive and hit a hill so the problem comes up, see what your pressure is reading. Early TBI big block should be same pressure as a TBI small block, 9~13 psi but I'd be happier to see it above 9. (94-95 are the oddballs at 26~32 psi due to an injector redesign and higher pressure pump to go along w/them.)

Would also be a good idea to test your TPS, it's been for freakin' ever since I bothered to test one because I hardly ever see them bad but it does happen. I'll see if I can dig up the info on it. It's only got 3 wires, basically you're wanting to see a range of one voltage to another with no spikes or dead spots in it. If you think you'll have time to check it I'll dig up the info. But not if you're gonna read it and never get around to it.

Richard

yea I put new fuel pumps in it in feb. and I have a gauge on the back of the tbi and I've bumped my pressuer up to about 11psi I'm going to swap out the tps with one that I have on the shelf and see what that does. but I'm starting to think we put to much degree in the cam, so I'll keep playing with everthing eles before I tare back into it to check the cam