Trying to narrow in and tune my car 88 lb9 auto stock.
I still have more tuning to do but I have replaced the fuel system from the tank to manifold. Not injectors. TPS/IAC adjusted seem to check out. Base idel is at 5 (not 6) so need to tweak. Vac leaks appear fixed. I am using Tunerpro and Autprom.

I have not cat but still have air pump installed

Car starts up and idles ok. After TPS/IAC adjustment it idled better no misses or knocks. but it is very rich like pass out rich after a minute you can see gas fumes. LOL. It idles in the ECM between 700-850 bouncing but it idles up once warm to 900 even 1000 and little gas will kick it down for a few seconds.


The car is running rich but the ECM appears to be super lean. so it is adding more fuel. I let it warm up for minutes but doesnt seem to to go to closed loop often. I let it go over 180f in the ecm but still stays open?

so what can keep the car from going closed? and in open loop the o2 sensors are not used?

My readings for BLM and Base pulse correction are fixed at 128,
My Pulse width is 135-200 but looks like 180 average

My o2 seems stuck at .444v might fluctuate down to .3 but not a lot of movement but I still get cross counts but small. Over about 3 minute datalog had about had 190 cross count but only add up when I give it gas.

my knock count is at 23 in 3 minutes.

MAF readings seem way off they are around 2500

IAC counts go straight to 144 and fluctuate slightly

EGR seems to be at 0 at idle and bounces to 25 sometimes

So my conclusion but please help:
1: MAF could be bad or have bad ground initially
2: O2could be bad (but this should not effect open loop condition?)
3: Temp sensors appears to work and this is what drives the closed loop at first?
4: Although all ECM points to lean, all my sensors are also reading lean or operating to lean conditions. Meaning the IAC is trying to stop adding air, the fuel system is dumping and the knock sensor is seeing knocks.

Car doesn't appear to knock but it is loud no cats. My conclusion is fix/check the grounds to the o2 and maf but that shouldn't be my main open loop problem

I am thinking: The AIR pump since missing CAT maybe is stuck and dumping air leaning things out so bypass that as test. Could be dumping to manifold making it leaner as well.

And maybe my original injectors are stuck open or dumping? although the faulty maf aside unburned fuel will read as lean to the o2 ecm and it hence it compensates with more fuel.

 

Some of the values you posted don't make sense. Such as this:

> Base idel is at 5 (not 6) so need to tweak.

and this:

> MAF readings seem way off they are around 2500

Maybe bad data from the data logger?

In open loop the O2 sensor reading is not used. But the current previously learned BLM value is.

The O2 sensor not being active is what is preventing closed loop operation.

> IAC counts go straight to 144 and fluctuate slightly

This points to an engine that is struggling to run. Is the engine tune-up OK? That is base timing, plugs, cap, rotor, and valve adjustment...

If this is an '89 (Multec injectors) the first thing to do is to get some new ones. The Multecs fail by the coils shorting out. Even if it is '85 - '88, replacing or at least getting the stock ones cleaned is a good idea.

RBob.

 

Sorry for the confusion:

I checked the base idle with timing light and I was around 5deg (to the left of the big V that is advanced right?) I meant in the ECM the BIN calls for 6deg but that should not cause that much trouble.

My MAF readings in Tunerpro are registering 2500grams/sec at idle. Normally at idle values should be like 8-15 g/s and I think maxes out at 160 on stock unit. So something is wrong there. But again, since open loop mode it shouldn't matter, it runs off default tables.

The O2, I just learned, and the CTS control the open loop-closed loop transition. My CTS seems ok and reads 185F after warm up (soley?). But my O2 never crosses to .5volts. I thnk it needs ot go over .5volts for it to switch. SO I need to verify ground and replace.

Also I suspect my AIR diverter system could be cuplrit. The PO removed CAT and I see broken lines near the AIR. I am thinking it it stuck in exhaust mode and could be dumping air all the time to the manifolds creating lean condition.

As for the running state. The Car kicks over and starts up fine with 1 turn of the key every time. it idles right into the 600-800 rpm range. stumbles a bit for first 5 sec and then just idles all day long but rich, give it gas it sounds ok but still rich and kicks down a little.

I have original injectors in there still. 1988 ones with cold start. I have seen the writeups, how hard is it to swap injectors? It is probably a great idea and great way to really have access to top of engine and clean things up, reroute new vac lines etc.

 

When you checked your timing, was your EST disconnected? At idle, for base timing and everything connected, you should see 15 to 20* BTDC. Just a thought. It might not be the only issue, but it's worth fixing to accurately fix the others.

 

Yes that was with EST removed. Well more news. :ast night wanted to pull codes and got code 34 and 42. no surprise. PO also has many wired under the dash that pull power but also a few that come from the ign coil and relay area. I think to an old alarm and power for stwereo too. Not sure what I can remove. I guess I will like to post a pic to see from you guys what looks stock and then I will remove one at time try to get back to OEM wires. Any ideas on how to to do this right? tips?

Well I tried to measure voltage at the MAF plug while unplugged with car on. Is that the way to check the voltage? I could not get any readings and plugged or unpolugged car ran no differet. So I am thinking the relays are bad.

The ignition coil,cap,rotor all look original and very old. I guess best to replace, maybe start with coil and ICM first and check modules.

as for running rich i checked a few plugs and they ohm at 16.6+

maybe the spark is missing on a cyl or 2 and hence my rich condition as well.

so again any tips/ideas to check previous owners mistakes, which harness to start with or how is simpleest way to check? I was thinking look at schematic pull MAF relay for example and just do conitniuity to maf and if possible ecm.

 

well quick update. I bougth a new ICM, coil and relay. I cleared codes (first time) and let it run for a minute but code never came back. Still ran rich but smelled much less. Wonder if clearing code helped issue? I still have to check MAF voltage and ground to ICM white wire to be safe

but maybe got lucky? doubt it lol.

 

CHANGE UR CAP , ROTOR , PLUGS, WIRES, fuel filter , and put a heated 3 or 4 wire o2 sensor in it ! ASAP and in That order IF u can't afford it all at the same time ... Then if It ain't fixed ask questions ... There is no possible way anyone here can help u Find out what is Wrong with ur car when it sounds like it ain't had a tune up since 1990!

And there is no possible way to tune a car that is not in perfect MECHANICAL working order ... After u replace all the above a timing chain is next .... Also the ohm (resistance) of a spark plug don't tell u crap about it ... U need to pull a couple plugs out of the head and visually and thoroughly inspect them ... If they look wore out replace them all with regular old cheap *** ac delco plugs it'll b like 12$ ... Also make sure u GAP them ! I also radius all of my plugs

 

Hello I agree with you. Well changed my coil and inspected some plugs. They surprisinginly do not look took bad, slighly carbon but little brown (notmal) at least not lean.

Fuel system is all new: fuel tank, new lines, fuel pump, filter. I am getting 39-41 psi during run time. It leaks down to about 20psi in about 20-30 minutes. (is that bad?)

Plugs and wire look brand new unburned.

Still is a rich issue probably an intake leak, injector, or egr/AIR system. But overall the car runs and drives and I have not put on the street yet. I also am working on interior which was a mess. So I decided since I am doing 2 things at once I will focus on completion of something and get interior out, body panels, dash, repainted, lay new carpet stereo and seats. so I have a car I can sit in without leaves, rat droppins and smells lol

Otherwise car runs and I need to get her on the street to tune it out, sitting in driveway will not get me much. So once interior is done I will replace the cap rotor plugs wires. then drive it. Quick wd40 spray test I saw the idle bumped up a little around the top plenum intake.