Hmmm

Since your O2 is reporting rich (voltage above 750 mV for over two minutes) it does not appear that it is bad. A bad O2 usually goes into lean direction (reading low voltage). Another possible reason for a rich condition is a dead cylinder - no spark at all.
I am not sure (since you have '88) if your TPS is adjustable or not. At idle TPS should report around 0.60 V (0.3 to 0.9 Vdc is acceptable). Adjustable TPS will have one of its mounting holes slotted. If it is not than ECM has ability to determine 0% TPS on its own. Take a look at TPS and plugs first before blindly swapping parts.

//RF

 

both screws are torx so im assuming that the TPS in non adjustable , tomorrow i will check all my spark plugg cables , i think number two got burned a little bit from touching the exhaust manifold , not all the way , just the outer layer , the TPS connector is fine , only the rear clipping part came loose , i will go over this stuff and update ASAP. , i should be getting my datalogging tools tomorrow , maybe i'll post a datalogg vid .

 

any updates????

//RF

 

i checked all my plugg wires yesterday , and they seem to be ok , i got my ALDL cable back but cant get the software for my usb to work right , other than that i havent been able to do much due to the rain . hopefull it clears up so i can spend some time under the hood , will update ASAP .

 

UPDATE : finally got my ALDL software running correctly , I will data logg tonite and try to post the video tonite , BTW i noticed my IAC steps were way high ,almost 50 , and my TPS was reading around the same area too

 

Post a log where you go from start to idle - about 5 minutes should be enough.

 

ok , finally uploaded the log , i added somemusicjust soit wouldnt be a boring 5 minute video , btw this i started recording after 2minutes from starting the car .

http://www.youtube.com/watch?v=rPFNMJud3sc

 

Looked at your Youtube vide. There is a easier way - have WinALDL save captured data into a log files and then compress them with ZIP utility and upload to TGO. Youtube does not allow to look at all sensors systematically.

The weather is nice - got to run now.

//RF

 

yeah , when i try to actually dat log it wont save , so thats why i did the video.

 

have you tried driving your car with a hotter thermostat, such as a 180... ?

 

If you're not using a timing light, that would be my next step. Dial the timing in precisely to spec.

It's easy to guess and go by sound, but every car I've come across that was set this way was several degrees off when the light was hooked up.

Retarded timing causes the engine to show rich exhaust at the O2 sensor.

 

i used a timing light , advanced or retarded or set a 0* TDC it still runs rich , and my thermostat is a 195* from A*** zone. it said i was the stock thermo.

 

guys ... i just took a second peek at my passengers side plugg wires and found a cracked plugg wire . it is cracked right above the boot, thats why i didnt see it the first time ,also the red wire that runs from my battery to my alt. fell apart when i was holding it . i know that the cracked plugg wire could be a major role player in my "rich" problem , what role would the broken red wire play in my problem ?

 

sorry for not updating in a while , since my last post i have replaced all the plugg wires with straight botts instead of 90* angled boots " no more fried wires " and replaced the red wire that goes from the alt. to the battery . the car still runs rich , wich makes me wonder , could all that rich running possibly have fouled my pluggs ? just letting the car idle for 10-15 minutesgives me 20 knock counts . still dont know how to capture data from WINALD ,i press the start button on the datalogger and nothing happens , it just switches to stop , and i get no saved logg

 

ok , sorry if i mess up the post , i've never attached a log
I tested my fuel pressure and its @ 11 PSI during idle , the log is from start up , idle for 5 minutes then i shut it off . I only logged the sensors .

 

I took a look at logs and plotted some parameters to aid this discussion. Based on this 5 minuted data log is that your engine is running rich.

Why????

It appears that ECM is able to take out enough fuel (BLM=108) to keep your engine idling in close loop. BLM = 108 is as low as stock ECM code will allow for ECM to lean out your fuel mixture. Typical O2 readings should bounce between 0.2 (lean) to 0.7 (rich) V. and in your case 0.3 to 0.9 V as O2 sensor reacts only to the presence or absence of oxygen in the exhaust. It has no way of knowing where the extra oxygen came from. Based on your posts (I could be wrong, so please comment) O2 is original and was never replaced. In any case all indications point toward tired O2 sensor. Replace it with DELCO unit (BOSCH and others have a different response characteristics).

In your previous post you mentioned that your FP = 11 PSI. IMHO it is border line, but still should work. Take a look at your injector fuel stream - it should be nice mist without any large drops. Lower fuel pressure tends to reduce atomization which will result in fuel puddling -> rich fuel mixture!

Which leads me to a question - do you have 350 injectors sitting on top of your stock 305 engine????

//RF

 

thanks for the info RFmaster , Previous owner didnt say anything about the o2 sensor being replaced , so im assuming it WAS the original .I replaced the o2 sensor 5 times since then " rich condition " all were bosch o2 sensors . As for the fuel pressure , well ... i installed new gaskets and diaphragm on the TB , i switched out the stock regulator and spring and replaced the spring " from 1989 GMC suburban " and the regulator from a 1990 caprice . i still have the stock spring but i drilled out the stock regulator " trying to make AFPR " , before all this the car ran fine with a small scent of fuel " old o2 sensor " until i blew head gasket , then i did a rebuild and also replaced valve seals and machined heads " usual things to do after a blown head gasket " then i put it back together but it ran rich " i was told it was just oil burning off , my overflow tank filled up and bubbled to the point where it almost spilled out of the tank , so i was told that my CF relay mightbe out , so i bypassed it to keep the car cool @ all times then drove it home removed the bypass and pretty much its been the same ever since , except for all the new sensors and stuff . Here's a theory . imagine cooant is leaking into a combustion chamber then it is sent out through the exhaust valve where it meets a hot exhaust manifold where it is quickly turned into steam ,then the o2 sensor reads the steam as o2 thus making it think its running rich . possible ? BTW i think pluggs are fouled , i have new delco pluggs , i just dont want to put them in yet because of the rich condition .

 

Anti freeze is known to kill O2 sensors. O2 sensor is a differential device - it uses the difference in O2 levels between outside air and exhaust gas stream to create voltage differential which ECM uses to control fuel mixture. A splash of antifreeze, oil or household RTV will destroy this delicate sensor.

Antifreeze, oil, lead, rich mixture and silicone all can conspire and kill O2!

As for the steam theory - the antifreeze will deposit itself onto O2 sensor tip - contaminating O2 eventually. There is a simple check that you can perform with propane burner. Check post #15 in the following thread:
http://www.cadillacforums.com/forums...nsor-turn.html

• False rich indication (high O2S readings) can be attributed to the following:
• Contaminated O2 due to additives in the engine coolant or due to silicon poisoning.
• A spark plug wire too close to the oxygen sensor signal wire, which can induce a higher than normal voltage in the signal wire thereby indicating to the computer a false rich condition.
• A loose oxygen sensor ground connection, which can cause a higher than normal voltage and a false rich signal.
• A break or contamination of the O2 sensor wiring and its connectors, which could prevent reference oxygen from reaching the oxygen sensor resulting in a false rich indication.



//RF

 

no false rich conditions here . white smoke that smells like gas is what we have here. all my o2 sensors and pluggs turn black "not oil " . sometimes when i give it gas , the asphalt beneath the exhaust pipes gets moist .

 

It is a long shot, but worth a check - take a look at injector part numbers - PO may have installed 350 injectors.

//RF

 

how would i do the test if my o2 sensor isnt heated ? , his o2 sensor is heated . no i do not have 350 injectors . injector numbers are GM5235279*RPD

 

BAD NEWS ! , I just re-installed the injector that i took outto read the numbers , and i pinched the O-ring and when i tried cranking it fuel sprayed all over the engine bay , it soaked the hood insulation with gas and it leaked all over me when i opened the hood . how long should i wait for the fuel to evaporate , i cleaned some of it off , should i rip off theinsulation just in case ? looks like it only sprayed on the drivers side , it wet the injector connectors and some other things , will update asap.

 

Sorry about all the trouble dude. I had this 'shower' before and I did not like the skunky smell either! Injector O-rings can be a pita. Let the gas evaporate overnight. Couple of days should be enough (with sufficient ventilation). Try to soak up excess gas with rags, etc and get rid of them (plastic bag in GC). You have stock 5.0L injectors. Do not rip anything off - we have relatively low evap pressure gas and it should be evaporate quickly. Naturally for safety sake make sure there is no sparks or open flames!

The O2 test with propane torch can be used with either heated or single wire O2 - you are looking for voltage change. Sensor should be hot ~ 600F for voltage readings. You are right - single wire sensor is a bit more difficult to test.

I have some spare injectors and O-rings if you need them. I went through my notes - you may have a sticky injector dumping excess fuel that maybe causing all this mayhem.

//RF

 

Thanks for the moral support lol , yeah I ruined one shirt and thank god I stopped cranking the engine just in time , I thought it was flooded so I stomped on the gas and cranked it , it sounded like it had a hot cam in it , man was I wrong , I could blown myself to bits . As for now I will wait until Sunday to work on the bird , I have been requested to play a show in Tijuana Mexico lol , I will update Sunday afternoon , I suspect my heads may not be torqued down to spec or may have gotten loose since I only torqued once during rebuild . Coolant getting into Cc . Maybe ?

 

Hey - just take it slow and easy. It is all too easy to jump to quick conclusions that may lead down to dead end. Been there and done that .

Have fun playing down at TJ (just be careful).

I have a busy Sunday planed for me and I'll be out of range of computer.

//RF

 

back from mexico ahead of time , i will inspect the O-ring tonite and clean things up , i also added some more coolant to the reserve tank "just to see if coolant dissapears " other than that i cannot think of anything else that i can do to help find a fix to this problem . BTW RFMaster injectors have been serviced by Witchunter performance . Also if 11 PSI seems a little low , what can i do to raise FP besides AFPR , i've read that aftermarket springs are BS , I will switch back to original spring just to see what happens.

 

Get new o-rings - it is not worth screwing around with questionable ones. Since injectors were serviced by Witchhunter (I use him as well to service my injectors) then injector question is kinda moot. As I have mentioned earlier low fuel pressure results in poor quality fuel spay cone emanating from injectors - fuel droplets tend to be larger and consequently you have a lot more fuel in intake. Try stock spring and see if it raises fuel pressure - I do not expect huge jump. In my stock 350 I run 14 PSI (with JET adjustable FPR) and do not have any problems at idle, but I also run custom tune. This leads me to another thought - did you change your cam or ported heads during your rebuild?? Based on you data log your MAP values are right where they suppose to be at idle (28-35 kPA), but it possible that stock idle VE values (in your EPROM) are just to high for your engine combo and ECM simply runs out of adjustment range (very low BLM values).
All of this assumes that you do not have internal coolant leak. Do you see any bubbles in radiator when engine is idling?

//RF

 

when i did the upper engine rebuild "heads , valve seals , gaskets " i only had the heads milled down just to make the surface flush again , other that i never touched my cam or anything else so the engine is completely stock . At the moment i can not check to see if i have bubbles in my reserve tank , I cut the O-ring inhalf and the upper injector pod gasket was done for . Monday i shall pick up some O-rings and a new gasket then i will update ASAP.

 

Ok , so i just recieved new O-rings and gaskets i also bought new o2 sensor and pluggs . Last night i was going to install the new pluggs and found out that i had two different types of pluggs . i took out 1 and 3 cyllinder pluggs and they werent the same , # 1 was R45TS and #3 was R45T , the new ones i bought are all R45TS and the old pluggs were black and soaked with gasoline , here are a couple of pictures . BTW i also noticed that on some of the gaps on the pluggs got smaller , i will post a new Datalog with fresh pluggs and o2 sensor ASAP.

 

do you have headers? those short ones may have been used for easier installation...

 

Prefix and suffix letters are used to identify a specific type plus the numbers relate to thread size and heat range. For example, the R45TS spark plug decodes as:

• R = Resistor
• 4 = 14 mm Thread
• 5 = Heat Range
• T = Taper Seat
• S = Extended Tip

Extended tip plugs are better suited for lower compression, street motors = LO3. Check spark plug gap and spark wire resistance since we are chasing, what looks like, weak ignition.... A conventional 7mm spark plug plug has a resistance of 10,000 to 15,000 ohms per 12" --if it's if it is significantly higher, the wire probably is bad.

//RF

 

the plugg wires are new , the only things that i changed on the ignition system are the ignition control module " in dist. " , new rotor , pluggs and plugg wires , can a bad ground give me a weak spark ? there are 2 grounds straps going from the drivers side head " i grounded the one coming from the thick harnes behind the dist. to the intake manifold . the other ground goes from the head to "forgot" . and the one ground on the passengers side head that goes from firewall to head , the only after market ignition component i installed is the MSD blaster coil "waste of money" .

 

Grounds are very important for ECM operation, so try tying them down.

About a year and half or so ago we had a similar thread with engine not starting or stalling all together. It turned out to be a combination of ignition control module (ICM) having a poor ground inside dizzy and a flaky ignition coil. It is common mistake to put too much silicon heat sink compound between ICM and mounting boss. Only a thin layer is needed not a thick bed as if you are laying down at tile in a thinset! If you have OE coil - give it a try - MSD primary coil might require ICM to sink a lot more current which it may not be able due to a number of reasons.

//RF

 

when i installed the new ICM it came with some white grease i only used a little bit then spread it out with my finger . i've read on here that the msd coils really dont do anything unless it is being used with one of their ignition boxes ,thats why i havent tried buying a stock coil " i threw away the OE " . i want check for weak spark , do i just hold the plugg against the wheel fender or something , i wouldnt want to shock myself . pink is bad and blue is good right ?

 

Clear Sinuses is better...

 

As long as you have a spark between center electrode and L bar you should be OK - color - I do not know, but blue is good.

 

after removing the rest of the spark pluggs all the gaps got smaller , they went from 45K gap to almost a 30K gap , kinda like they melted or something .

 

Check your under-hood label, but IFRC 0.035 is a stock spark plug gap for 305 TBI R45TS

 

forgot to mention that i filled the coolant reserve tank to the "full when cold " line , i havent started the car for probably a week and now the coolant is below the "fulle when cold" line , BTW engine was cold when i filled up the reserve tank .

 

pluggs were re-gapped to 35K new o2 sensor is in , will post a log tonite.

 

@ RFmaster correct me if im wrong , ECM is pretty much reached the limit for leaning out the AFR , the o2 sensor reads rich due to the excess fuel in the AFR yet ECM can no longer lean out AFR . This looks more like an ignition problem or a fuel pressure problem ,right ?

 

well , i just got done doing another data log , before doing the log iinstalled new pluggs o2 sensor and a stock coil , i looked in the reserve tank while it was idleing and i got very few bubbles " 4 or 5 bubbles " .

 

You're right - ECM railed out trying to lean out fuel mixture with 108 taking out as much fuel as it can. And that's the reason why I asked you to verify injector part numbers to make sure that you have 55lb (305 stock) injectors. Sorry about that skunky shower the other night!

The question why is she running sooo rich with stock injectors and stock pressure??? Where is the extra fuel coming from??? Cracked fuel pod, leaky fuel injectors??? This is all assuming good ignition and combustion (and non poisoned o2 sensor).

Try disconnecting one injector (engine off, start-up) at a time - ECM - engine should be able to idle with one injector - while data logging. If there is a significant difference between the two - it is worth looking into. For example, if one requires lower BLM value - that might be the leaking injector! Higher BLM = ECM is adding more fuel. If BLM is low that means ECM does not need to add as much fuel (idling on a single injector) to keep engine idling in CL. Therefore, that injector is somehow delivering too much fuel.


//RF

 

i will try that tonite , will i have a rough idle ? , like i mentioned before that i thought maybe i have a blown HG turns out that more than likely its not a blown HG , i looked inside radiator and my coolant level was below the the port leading to the reserve tank " thats why my coolant kept dissapearing " . The reserve tanked is filled @ " full when cold " level . Also my injectors have a nice spray , no drips or anything , the fuel spray does hit the bore walls " good or bad ? " oh and last datalog was with fresh o2 and pluggs , did it make any difference on the second log?

 

It is tough to diagnose problems by not being there! So that is the reason behind all questions and suggestions. Since you have doubts about HG integrity, perhaps, it is worth it to spend the time and perform a cylinder leak down test. Car Craft had a good writ on this subject in April 2009 issue:
http://www.carcraft.com/techarticles...ter/index.html

On a single injector test - it is a crude, but effective way to see if one is delivering more than the other. I have a friend of mine who a while back bought 3500 87 truck with 454 from less than reputable person (long story). Engine run, but lacked power above 1800 RPM. Changing filter, fuel pump did absolutely nothing - we had 14 psi and plenty of volume. The injector check revealed that some one (probably PO) swapped out one of the 85 lb injectors with 45 lb-Hr from Astro van. Go figure! After replacing with a correct injector engine pulling power was back.

From your description it sounds like a you have a pair of healthy injectors. The only other reason for engine to run rich is that stock VE table (in your ECM) is too rich for your engine (after rebuild). Assuming that your engine is healthy and there are no other problems the way to rectify this is to reduce VE values in idle area of the VE table.

//RF

 

so that means a whole new tune ? if so that would really blow D*** since i have no tunning knowledge or hardware . i tried the injector test but didnt datalog , when i ran the engine with only the passengers side injector plugged in it ran without barely any smoke ,then when i ran it the the drivers connected and passenger disconnected it threw a big puff of white smoke and almost wanted to die kinda like a chug chug chug CHUG CHUG CHUG chuuug chug then after a couple minutes the idle smoothed out a little bit . also tested spark and it was blue with a yellow tip .

 

well i just got back from idleing the car for 40 minutes ... i got the bubbles in my reserve tank and right before i turned it off i gave it two revs " almost WOT " then i looked at the rear and saw probably the biggest man made cloud , then when the smoke cleared the floor was soaked , not a small little drip pattern , i mean soaked . SO here's my theory and more than likely its a fact , i have blown head gaskets on both heads "crossing my fingers and hoping that they aren't cracked " . the coolant was making the o2 sensor go crazy thus giving us a false rich condition .

 

Dude

Sorry to hear this.

//RF

 

You know most people would go straight into FML mode , i'm looking at the glass half full , thanks to this experience i have learned alot form you and Rbob , and i thank you guys for teaching me these things . Money comes and goes yet experience stays with you until you die or suffer severe head trauma lol , once again thanks to all who chimed in , as for now the hunt for 187 heads begins , " i have a feeling that they are going to be cracked " will update when all repairs are done .

 

Last October I tossed two sets of Vortec heads (both sets were 062 castings) into a scrap bin after spending $90 for magnaflux (in addition to acquisition costs). I was planing to use them for 383 build. Both sets were cracked right in the middle - between the two adjacent exhaust ports! False economy - lesson one.

//RF