Hello,

I am new here, have been reading and reading and searching until I cannot search anymore. So, I have resorted to posting and hopefully getting some needed assistance on my project before I continue to keep guessing and sometimes making things worse. I will greatly appreciate any help I get!

This is a swapped LT1, From a 1995 z28 w/ 4l60e.
The swap was done to a 1983 Blazer s10

I traded for the Blazer (wanting a project) and seem to be having more issues at the moment then I can knock out right now so am needing some help.

The Motor is a 383 Lt1, ported lt1 Intake Mani,58mm Holley TB, Cammed, Pistons, Stage 2 Porting, LT1 290 Hydraulic Roller -12 1.6, Valves, Springs 11:1 comp. I have a build sheet which dates back to 2000's. I am from what I was told the 3rd-4th owner of the Blazer and the last or couple owners have not taken care of it and kept it in tip top shape. I am now getting into it and some maintenance I have done, or was done when i got it is:

New Optispark,
8mm Summit Wires
Autolite 104 gapped .035 from my research is what the motor needed, Plugs before were heavily fouled out. Wires were brittle.
New Intake Mani Gasket
New Valve Cover Gaskets
Couple new Vacuum Hoses
Changed oil and Filter
Trans had filter and fluid done (2nd slips) -Ill explain
New O-Rings on Fuel Injectors
Painted Intake Mani-Freshen it up a little bit
EGR Block off kit
Cleaned MAF With MAF Cleaner and also cleaned the IAT

After doing all this and removing EGR the Motor ran great, was idling well, sounded good. The reason I did all of the above was 1. It needed it, 2. It has been running LEAN-Eyes Burning and so forth since I traded. Let me also say the motor had at one point 100-150shot nitrous hooked up. the Intake Boot was plugged and there was a massive leak on the bottom of the intake from the PO who did not fix it, but I have fixed that issue. I have checked numerous vacuum lines over and over, fuel pressure is consistent around 35-40 while idling, 41 or so running around town. Oil pressure judging by the gauge that just decided to start working is around 35 idle 70-80 when under throttle it seems. The Oil is 5w30 synthetic valvoline.

When i had the Intake Manifold off, valves off and the fuel rail off I did a Leak test and did not find a leaky injector by priming the rail.

As I was putting everything back together and bolting it up my father messed with the IAC just a little, moving it around and what not. So i am unsure if that might be of an issue right now. But, heres where I stand right now with the motor and what I know.

Idling, it idles fine could be a slight miss but it runs really lean on idle... If i get out on the highway or street and drive it, it does great, it seems to be loading up somehow and my guess is that the AFR's are off because the motor has not had a good tune. The Tune I was told was done by Ed Wright which is about an hour and half away from where I live currently. I keep getting the sense that It still needs a good tune done (not a mail tune). 1. because the nitrous system is no longer on the motor. 2. I deleted the EGR system it needs to be turned off in the PCM. 3. Because it runs lean.

I am sorry that my explanation seems to be all over the place, however I am doing my best at what I can tell you guys.

My next question is, I was able to somewhat get a good 1-2minute reading through TunerPro RT and I saw alot of codes, and some issues that I thought might be wrong. Upon Starting the Blazer the Left and Right o2's were way apart from eachother, first in the high 250's for the left and then the low 150's even down 60's for the right. ended up being about 150's left and 60's or less for the right o2, I have not cleaned these yet but will it help or should I grab some new ones?

I have saved the File from TunerPro RT for the little time i was able to get in and get something (the connection broke). But is there a way I can upload it here for you guys to see whats going on and give me a better idea? This thing shows alot of codes, but the CEL is off so i am confused.

Anyway, If you can point me in somewhat of the right direction I will definitely take the advice at this point. And also let me know where I can upload the Tunerpro file so you guys can download and take a look please.



Thanks! Appreciate any help
Brandon

 

Most here will ask you to use Datamaster for logs and to upload files in .csv format. Any file sharing site will work just try to pick one without a ton of dirty ads. You can also email the files to anyone interested.

As far as the O2s go, I wouldn't try cleaning them. If you check around you can get a pair of replacements for about the price of a single unit from a local parts house. I think I got my last pair from Rock Auto for $65ish delivered to my door.

 

Is it a factory LT4 intake manifold? Are the heads factory LT1? Did they machine the top of the LT4 intake to eliminate the interference between the top of the manifold runners and the valve cover rail on the LT1 heads?

 

I just learned about Datamaster last night, . Once my obd2 connector mini usb thing gets fixed I will try to log more with the right program. I will check into that and grab some new o2's to see if it clears up the lean running condition a little bit.


The Intake Manifold, now that I have really looked into it is not an lt4 manifold. the numbers doesnt match up and its been drilled for the egr system which i read the egr system was never on lt4 manifolds. Sorry about the mis information.


Well, if someone doesn't mind at the time if they would please look at what i currently logged through TunerPro RT I would be grateful, at least until I can get my connector fixed or order one through moates.

 

I have a factory LT4 intake manifold. It has the same provisions for the EGR system as the LT1 intake. They just didn't need to install the EGR system on the LT4 Corvette engine.

From the outside, other than the taller runners and the red powder coat, the LT4 intake is identical to the LT1 unit. Internals are also identical.

In addition to TTS DataMaster, there is also a free 94/95 scanning program download available, and a recommendation on the required cable. Look at the "sticky" on the "Computer Diagnostics and Tuning" forum.