alright im having issues with my swap running extreamly rich to the point it has constant smoke at idle an looks like a diesel when reved. specs are 01 lm7 with gm hotcam ls1 intake 99 fbody exhaust manifolds 3in y pipe no cat single in/out magnaflow mail order tune from tunedbyfrost.com. ive relplace map sensor am running the later style lt1 02s. ive had it retuned again since he didnt change my tach output the first time and still the same. im running a 4thgen fuel tank and built my own fuel lines with a late 3rdgen tpi filter inline in stock position. its not throwing any codes when checked but the ses light stays on.

 

Hook a scanner up to it and monitor the sensor feedback, particularly the short term fuel trims and front HO2s

What did Mr Frost have to say? He's very knowledgeable when it comes to hybrid tunes

 

on the first tune it didnt seem to smoke so bad but seems to have gotten worse since i got the retune for the right tach output. i had 5gal of gas in the tank and only been running it in the garage and some in the driveway no real driving and it burned up that little bit in just a short time considering all ive ran the thing. ive got a video of the car running that shows how it was before i had my retune. im tryin to find someone who has a scanner that will swing by and help me out. what type of readings should i be looking for? i started it today and it ran rough hard start and smoothed out once i held it at about 2k for 30sec or so but still smoked. i reek of gas whenever i come in from working on the car and had it running. smells like i spilled gas on myself.

 

Dont keep running it. It doesnt take long to wash rings out and then your really up the creek. Your sure your MAF and O2's are in good working order and wired correctly? You really do need to connect with someone who can plug HPtuners or the like in and sca it properly so you know whats what. Its likely not the tune Frost is very knowledgeable so id look at hardware and/or potential wiring problems first

 

Yes I'm pretty sure its not the tune but trying to track down what is going on is a nightmare. I've tried going through and unplugginf thins to see if it made a diff to try and track down a bad sensor. The car itelf isn't completely put together yet so I'd have to try to load it up and trailer it somewhere since then I'd have to borrow or rent a trailer. I want tp buy hp tuners myself but right now money is tight so that's not happening. Just hope to find someone with a scanner that could check it out for me.

 

You can check reference voltage and output at your maf, tps, and map with a mulitimeter or scan what they are at the pcm with a scan tool. If they're correct then it's your tune.
Think about it. Your pcm reads inputs and sends outputs (injector pw) according to the tune. So start by making sure it's getting the right inputs. Even OL isn't going to chug like a diesel.
Your probably pig rich in the tune, fouled your plugs, and as they fouled then things get richer.

 

Hate to sound like a newb but how do I do these things? Wiring and electronics are not my strong suit that's been the biggest obsticle in the swap. I'm glad I had Pocket build my harness though that thing is excelent!

 

Its pretty simple to verify wiring but painstakingly time consuming. FOr instance when i did my first LS1 swap it seemed to run just fine so I booked a dyno tune and off I went. Upon arrival we were WAY lean on the first pull which confused the tuner on the second pull as he enriched it and still same lean condition. After a half ohr or 45 mins of paying for dyno time he realizes that the TPS is not producing a proper signal so it wont go into PE ( power enrichment ) think of it as carb secondaries sort of. Anyways I order another TPS sensor all while paying dyno time and when it arrives I change it and NO change its still not working. So the tuner comands the PCM to go into PE right off idle and we hack tune it and lots of $$$ later Im on my way with a mystery wiring problem.

The way to check the wiring is by unplugging the PCM connectors ( Disconnect battery first ) and using a long wire run a continuity check from each pin and each sensor plug, back to the pin on the PCM plug that corresponds with the lead your checking. In my case the TPS sensor had been torn off by a previous owner or cut off about 10" back under the sheathing and the leads were twisted and taped not soldered so one had come apart and that was my cause. But by running a continuity check was how I found it. Do this for each of your wires and verify they all go to the right place and are all in good order and I think this is where you'll find your problem

 

went out to take a picture of something on the car and decided to start it and see how it acts. its been sitting not started for about a week and fired on first crank and no smoke on 1st start but after about 30-45sec of running it starts to smoke some. its in the garage so i didnt let it run too long but thats what i noticed that normal on cold start but starts after idling. now on a hot start it does it almost right off. i had a upstream 02 go bad on my yukon last winter and it smoked but ran really rough BUT its not cammed so i could be having the same issue but my car is cammed.

 

As pocket and everyone stated your best bet is to hook up with someone with at the least a scanner, hp tuners would be ideal. There are other variables also. Did your tuner program for the correct size injectors? Did you give the tuner the right info? Where you running old crappy gas?
Mail order tunes generally will get you close within a safe margin however will not be ideal. Hotcams are notoriously a pain in the *** to tune to begin with. Someone with your car on the rollers with HP tuners in their hand can't even nail a tune on the first hit. I don't know why people think you can mail order one spot on.
Not to be rude but I would recommend reading up and schooling yourself on basic injection. A little know how will go a long way. I don't want to scare you but to do a swap with a cam and not even know how injection works is biting off a lot.

 

it could be possible to have bad gas last time i put any in was a few months ago this weekend i put 5 gal of non ethenol 93. yes ive read that hotcams can be a pain to tune i int expect the tune to be 100% i do plan on going for a dyno tune when i get the rest of the car put together but right now it has no interior missing gfx ect ect car had been sitting 5yrs in pieces before i started the swap this past january. i know i need to learn some things but thats why i ask questions most people in my area which is farily rural dont even know what a ls1 is lol.

 

This is the correct way to test a harness with a mystery wiring problem. Since I built the harness, I already did this prior to sending it to him. The only possibilities with wiring are a broken wire or unplugged critical sensor. Both would show up on a scanner and throw a code

You can get a cheap one from harbor freight and do the job. It wont have live data stream, but will take snap shots and read codes which will put you in the ball park

It could just be bad gas too, but Id still hook up a scanner to be sure

 

I see. i thought it was a roll your own kind of deal I had no idea you did it up.

Scan the thing Screamin86

 

Well after work I'm gona try and check some sensors with a multimeter but I also have a friend coming over tomorrow that has a scanner and we are gona hook it up and see what's going on. I've never used one so what do I need to look out for?

 

A quick very basic crash course, and process of elimination.

OK, First off you have to understand cold air is denser and contains more air molecules which subsequently will naturaly lean your air fuel mix. Also elevation will have an effect on this as lower elevations will have denser air and vice versa (atmospheric pressure). So the PCM uses many means to compensate for the varying air densities or 02 content through various inputs. Your PCM also has many means to compensate for load requirements.

I don't have a wiring diagram but the TPS needs to be reading around .5 at idle and around 4.9 at WOT. Basically it allows your PCM to see the angle of the throttle blade and anticipate how much load and air will be entering the engine. If it's not sending the PCM the correct idle reference voltage then numerous bad things happen like not even running off the idle tables in the tune. If it doesn't read around 5v at WOT then you are leaving power on the table. I highly recommend making sure this is set properly.

MAF. This contains a heated wire that is thus cooled by the air crossing over it in a very controlled manner to allow the pcm a very precise measure of just how much air is entering the engine. The more air passes over it the cooler the wire gets. It requires a very straight and non turbulent air flow to accomplish this.
Some people think the screen on these are there to keep out large animals or something after they somehow escaped being caught by the airfilter. The screen is there actually to help straighten this airflow for a more accurate reading. You should also not be putting your MAF directly after a bend in the intake pipe as it will cause it to read incorrectly. The process of descreening your maf actually causes more turbulent air, this causes unmetered air to enter the engine allowing it to lean things out. So if your AF's are a point rich, ripping the screen out leans out the AF's and gives the false dyno numbers that the screen was a restriction and that you gained power by removing it.

So in understanding how easy it is to throw off a MAF reading. Make sure you haven't fogged it with K&N oil coating the wire, had it on a dusty shelf and covered in paint overspray from another nearby project or anything like that. However typicaly a dirty maf or one installed after a bend in the pipe will insulate the wire causing a lean condition. So I wouldn't speculate this to be your issue. Unless your MAF is just all out garbage then it could cause a rich condition. Also will give you a MIL unless the tune is just crap. You didn't mention having a MIL so again the MAF probably isn't complete junk however the tune is still questionable as installing a cam completely changes what your PCM is looking for as normal from your MAF.

Also check your CTS (coolant temp sensor) It's going to send a signal to tell the needs of cold start enrichment. It will start out high resistance and drops resistance as the engine warms up. So if it's reading out of spec then your engine could in theory be at operating temp however your PCM might think it's still cold and adding enrichment. Again, any haynes, chilton or gm service manual, or google for that matter will tell you how to check this. This is a very recommended thing to check as it will cause a very rich condition also will cause a...you guessed it. a MIL.

IAT (intake air temp) will tell the pcm the ambient temp and allow it to adjust air/fuel accordingly. It's worth checking for S&G's however I don't think it's even close to your issue. If you have the afformentioned f-body manual you simply read resistance across the two terminals and compare it with the chart listed of what it should be reading vs the current ambient air temp. If it's out in left field then you get a MIL.

MAP (manifold absolute pressure). This tells the pcm how much vacuum is in the intake which it then uses to determine engine load. Higher vacuum, higher load. Putting a cam in an engine completely changes the engines vacuum. This has everything to do with your tune again and will not throw a MIL unless it's in left field out of thresh hold.

Now there are different operating states that your pcm can be operating in. OL (open loop) where the PCM isn't using the signals from the O2's as they are not at operating temp yet. In OL your PCM isn't using the O2's to make any AF corrections.

CL (closed loop) now your O2's are up to temp and your PCM is actively monitoring them and if all is well will make the necessary corrections to AF's per how it's told to correct them via tables in the tune. Obviously if your computer can't compensate and get your AF's to target ratio then it's going back to open loop.

Limp Mode, This is where something is obviously fubar and your pcm is going to default to a very safe base tune that will be just enough to not blow up your engine and get you to a shop. This will be accompanied by a MIL (check engine light).

So in a nutshell, If your car is fogging like a diesel and your not so much a getting a check engine light. Then I would be seeking a retune.

 

Tried to respond to this before I left for work but my laptop decided to frezze up on me so I'm responding from my blackberry so bear with me lol. I do have a ses light that stays on but when I've hooked a generic code reader to it I have no codes. I'm running the 5 wire truck maf btw and I run just a dry cone filer I'm not a big fan of the oiled k&ns. I've thought about swping the maf from my yukon on the car to test it but if I don't need to I will not. Anyway I got an email back from my tuner today about the issue I explained to him and he gave me some things to try and check. Check for leaks in my y pipe around/near the 02s . He also said try to unplug both sensors and unhook batt to reset the relearn and start it and see if it still smokes since the 02s will not be reading if fresh air will be hitting them. I tryied it right before I left for work and it seemed to idle better but I didn't get to let it run long since I had to leave. Looked like it may had been smoking very little but its kinda cool and rainly today also so that doesn't help. I believe ill drop my y pipe and go back over all my welds just in case there Is a leak anywhere. Also since I used all 3in pipe up to the manifolds would it cause an issue since the pipes are so large?

 

If it does it when cold I highly doubt the HO2s are the issue. The PCM doesnt even read them until the PCM goes into loop

 

have you checked your fuel pressure? I had a buddy that made new lines on a fourth gen tank and i think he acidentally ran the return line in the evap line and the return flow was blocked. Just a thought.

 

It generaly takes about a minuite or so before it starts to do it. About when it comes off high idle. If I ever get some time to mess with it I'd be happy and maybe then I could sort some things out.

 

How far from the I64 and I81 merge are you? I live just north of Richmond but im actually headed to Lexington on Friday morning and will be there through Sunday. I work at a GM dealer and have a Tech 2 scan tool i can bring with me. If the timing is right i may be able to offer you some quick help at some point. Let me know......fellow LS swapper here haha.

 

About 5 miles north of the the 64/81 intersection.

 

Ok. I will PM you tomorrow. It shouldn't be a problem. Kind of works out since I will be right there.

 

Thanks! Now ill have to clean up the garage a little lol

 

Haha no need to clean up. I don't even have a garage at home so I've been working in the driveway.........although its a very clean driveway haha

 

well i believe this car never wants to live lol. the water pump started to squeel on me so i ordered a new one from rockauto couldnt bring myself to spend $135 for one at autozone. ive had this car since i was 16 was my first car and despite all the issues ive had with it i cant bring myself to part with it lol. if i ever do another swap and most likely i will i will do it in a car that started out in better shape! anyway.
with that said im gona go out and tinker with it before i head to work. i had noticed before Frost emailed me back that i had another symptom pop up. with everything hooked up after running for a few minuites it started having surging and if i blipped the gas it would have a hard time finding the idle and would almost die and wonder then catch itself and somewhat smooth out. if anyone is interested i can post the info my tuner sent?

 

The surging can have alot to do with the tune but a rich condition causing your fuel trims to be all jacked up could also cause it. I would try to figure out the rich issue first and then once thats straight an it still surges then there may be a tuning issue. based on who tuned it i doubt its a tuning issue. My car surges as well but its not tuned very well right now.

 

im starting to think maybe i botched up the valve seals on instal also. ugh but a scan should help me figure out whats going on. also how should i be running my pcv? im using the truck valve covers and the pass side only has one tube comming out on the front of the cover. i have the port from the tb to the cover then a long hose from the intake port to the pcv. i have a feeling i may have figured out the smoking issue since i had the vac line hooked to pcv.... am i correct? i went out and switched it around an just left the hose to the valve cover open and pluged the intake port and ran the hose from the tb to the pcv and it seamed like it isnt smoking....i need to hook the ho2 back up and see what it does now. if this is all it was im glad it was a easy fix but i feel like a moron. should i swap to the car valve covers that has two ports on the pass side valve cover?

 

alright well the car has had a few hours of runtime and drove it for the first time yesterday and ran it around some more today and it seems to run MUCH better the idle is consistant and doesnt wonder. when 1quickirocz came over and scanned it for me it was showing the pcm trying to pull fuel out and that it was rich but not throwing any codes. even with him comanding the ses light off it stayed on then randomly today it turned off for the first time that ive had all this in the car but now i cannot make it pop back on. so maybe there is an issue with the pcm? the car runs great though pulls hard! yesterday after my first drive i was wound up all day lol.

 

just went through this thread again....thought about it after you posted in my build. if you are still experiencing some of these issues, put another ground or two to the back of the heads. it worked for me.