I have had my car together for a few months now and can not resolve my Rich idle problem. Car will start right up and idle but I can't let it warm up because the black smoke is killing me. I have DM and looked at a few thing recently but I am a little confused about some things.

Description is in the sig.

My AFGS at idle is in the 20-30's. Is this normal with a supercharger? MAF is not on the pressure side.

There are no exaust leaks and the o2's are new. I changed them after I burned the coating on the pacesetters. I have a mail order tune from Madz, but this was only intended to get the car going then take it to the dyno. I have checked the bypass valve and every connector that holds all of the tubing together.

Plugs are brand new because they get fouled after a while because of the rich idle problem.

I am losing my motovation on this guys. I know everything on this set up is brand new I just can't figure out what the hell the problem is.

I have LT1edit and Tunercat.

My MAF reading looks kind of high, I even went in and resoldered the connections to my MAF relcation wire.

Any Ideas? Cause I am running out.........of patients.....time.....money............I just want to drive it this summer instead of just moving it in and out of my garage.

 

have you had it dyno tuned by someone that knows their way around the LT1 pcm? if you can datalog, I'd get a log and send it to Ion and he should be able to work some magic to get the tune better or give you an idea of where to start to get it running right.

 

Sounds like it may be a tuning issue but other possibilities are, MAF, MAP, vacc. leak, stuck/sticking open injector, etc. What is you ST and LT fuel trims, pre-O2 mV's, fuel pressure?

 

AFGS looks high, oure was 12-13 at 900rpm idle.
What BOV/Bypass valve are you using and how is it installed?

 

The bypass valve is the stock piece from Procharger. Everything is routed per the instructions. I can see where this is going.....been down this road before.
If there was a leak between the MAF and the intake the car would see more air coming in and add fuel, but the air isn't making it to the engine. Making it run rich as hell.

I have looked, felt, reconnected every damn hose on this thing and still have the same problem.

 

Unplug the MAF and see whats happening in SD mode... if it runs ok try another MAF.

 

I'll try that when I get home this afternoon.

 

Check your IAT sensor. Mine was bad and it was
showing -37 degrees, which caused the computer
to dump fuel. My motor would barely run when
it went into closed loop.

93Z,383,Vortech,NOS,water/methanol

 

So I dataloged a few things when I got home, First with the MAF plugged in adnd let it warm up and go into closed loop. My eyes are still burning and I had to change my shirt..........go thing the people next door have there A/C on!!!

Unpluged my MAF and the idle was almost perfect. No smoke or anything, smooth, about right at 900rpm. Let it run for a while til my laptop battery died.

But I did notice something strange my MAP with the MAF plugged in as at about 60-65 kpa, but with the MAF unplugged it went to 45-50kpa. Is this because it was running so rich?

So I need to go borrow another MAF sensor and try it out. Can't get that til tomm.

I guess this doesn't really mean the MAF is bad til I put another one on and try it. If I put a known good MAF on it and it does the same thing then what?

IAC was right on InsuranceGuy, Thanks!

 

If you go the same trouble widh another MAF make a copy of youre MAP table
0-50AFGS and post it here.

 

What injectors are you running? What are your BLMs showing? Could you send me your datamaster log? You may have the same problem we have with stuck 128/128 BLMs at idle...

 

So I chanded out a MAF with a known working one. Same result. But I did notice that if I compress the bypass valve tubing It runs a lot better, and the AGFS goes down to 12-15. When I let go it runs like crap right away.

So I pulled of the by pass valve just to make sure it is working. If I suck on the valve(vacuum) it opens, and when I blow it is closes but it is very sticky.

If it is stuck open at idle could this make my MAF reading wacked out?
Or if it sticks.

 

Here's some things to check or try:

1. Engine coolant temperature sender and wire. There are two of them. The one on the water pump is the important one.

2. Maf location. It is very sensitive to the direction of airflow especially if it is descreened. Make sure bypass air is not aimed at the MAF. Highly recommend moving it to the pressure side.

3. Lock the short term Blms to +-5 and the long terms to 0 in tunercat so no learning will occur in the computer. This will keep Blms from maxing out due to extra oxygen the exhaust. The car will read about 16 to 1 afr on a wideband when it is idling correctly with the blms limited.

4. Check for codes if its running that rich it will probably throw a code.

5. Get some catalytic converters. LOL

 

A 97ss 383 D1 3.4" pulley with Siemens 72# injectors.
Similar problems with and OBD2 car. Use LT1edit Ver 2.2.
I run Ganetelli MAF (I don't think it matters)
Cold... Adjusted low temp open loop lean. Helped with starting problems.
Hot (closed loop)... Adjusted low speed rpm (in fuel cal window) efficiency cal.
Adjusted MAF cal 2% lower with BLM update enable @ 50kpa. This helped low speed idle, and, AFR went to 14.7:1.
I tried -4% but this was too lean in closed loop.
Cruzing in closed loop mode is about an average afr of 13:1.
I use 2 evolution motor sports bypass valves after the intercooler (output). Run to ATI suction side (after) the MAF. MAF is on suction side of compressor. I prefer that cuz it stays cleaner.
When I loose air (blown air hose) the car will fuel rich. I cannot dump any air (exit to atmosphere) after it has been measured thru the MAF.

Hope this helps. I know how frustrating this can be. Mail order tunes are a risk, and, don't offer easy program edit flexibility (my opinion). B.