Series 2 L67 Laking Power *Data Vid Added*

[charliemax]

I suppose wd 40 would be a bad idea?

I'm not a big fan of WD40, except for specific applications. Like retractable antenna masts, smooth metal on metal apps. Although it has a solvent as an accelerant, it makes it's money as a water displacement (ie WD). If you don't want water and gunk to freeze up your antenna in winter it's great. I understand it works as a great laxative too, when administered bottom-up with the larger pump can.

Uh ya, any light general purpose oil. I use an old American brand called 3-in-1. The can is even shaped like an old small oil can with a flexible neck, so you can just do a drop in hard to reach places. I bought it to use on my boost bypass, because you can dispense it one drop at a time in tight places. I think a can costs $4 and is a lifetime supply. Whatever you use (no 30-40 weight motor oil, and nothing with graphite in it), don't swamp anything with it, and it should be fine.

I have been looking at the FSM diagnostic flow. If it's not obviously stuck or busted, there are some further elaborate checks to make. But we might be able to sum them up, by putting the car in neutral after warm-up, and do a quick push of the throttle into boost territory and see if the actuator moves. But first things first. I hope we find something out.

FWIW, I accumulate tons of worthless information..... The holding company of WD40 bought 3-in-1 about 10-15 yrs ago. The reason? 3-in-1 does everything WD40 does, except penetrate (which it does 90%, only for the first seconds you spray it) and displace water. WD40 couldn't claim any great advantage, and cost 3 times as much. It was costing them too much to try to take market share from 3-in-1.... so they figured if ya can't fight 'em, buy 'em.

That's pretty tough when your great new technology can't fight a product which was created shortly after The American Civil War. (1884, I think)

[l67poweredlss]

Tested the BCA and I think its good. When the car is off the lever sits @ about a 45* angle. Turn the car on and the lever shoots strait up. Pull the line and the lever drops back to 45* and vise verse when I touch the line to the nosel.

[Mechanical Mike]

Interesting thread.

Is the lever moving 45 or 90 degrees?
Make sure there's no gas in the vacuum line going to the fuel pressure regulator.
Refresh my memory, is the front 02 sensor always reading high millivolts & you have no current or pending codes?

[geofffinlay]

Gents,
Hopefully we're in the right area. I'm not past the MAP reading we got last time. Someone mentioned two MAPs on some vehicles? Are we sure that this has only one? If so, we should be able to apply a little pressure to the MAP, KOEO and see what the scanner tells us.

If the MAP itself can't read Manifold Pressure, (assuming the obvious, that the PCM needs that information) the PCM can't respond via the Injectors, which will be a similar enough condition to having boost with no more fuel.

It should also be possible to manually control the s/charger and measure manifold vacuum/pressure through the rpm range. I've never done that on this engine, but it can't be that hard.

Re backpressure, what's wrong with loosening the exhaust a little at the front and seeing the reaction?

Re the the front O2. If the O2 heater is working, when the engine is started cold, the voltage reading will be over 1volt (as much as 1.25), until the O2 begins to work. Before warm-up, the condition will be generally on the rich side so the O2 should toggle, but spend more time >500mv. The rear sensor will be rich >750mv until the cat lites at which point it "should" drop to around 200mv and stay there as long as the cat is controlling the situation. If the rear O2 starts to wonder up the voltage scale, there is an issue with the cat. That's how a cat efficiency code begins.

As long as the front O2 is hot/working it will read whatever oxygen is in the exhaust, relative to atmospheric. If the engine is turned off hot, then the key is turned back on, the O2 will be very low, almost (if not) 0.00mv until it cools off at which point the circuit goes back to its reference voltage, usually at 450mv.

As long as the O2 and the engine are healthy, hot and working, the O2 @ idle should toggle equally between about 150 & 850mv.

Regards and goodnight all

Geoff

[1fatcat]

As for the double MAP sensors, this can be tricky but, no GM ever used more than one MAP sensor. Some GMs used two pressure sensors and they may have even been the same part number, but they performed two different tasks and gave the PCM two different inputs.

One would be MAP (manifold absolute pressure) and the other would be a BARO or Barometric Pressure Sensor. The MAP tells the computer the air pressure/vacuum inside the intake manifold, and the BARO tells the computer the outside air pressure. The BARO input allows the PCM to control the engine in high or low elevation or anywhere in between. This can be done other ways too, but some vehicles used BARO sensors/inputs to do this.

[Mechanical Mike]

I'm not sure which years but the L67 has two MAP sensors. One for the PCM & one for the boost gauge.

[charliemax]

As for the double MAP sensors, this can be tricky but, no GM ever used more than one MAP sensor. Some GMs used two pressure sensors and they may have even been the same part number, but they performed two different tasks and gave the PCM two different inputs.

One would be MAP (manifold absolute pressure) and the other would be a BARO or Barometric Pressure Sensor. The MAP tells the computer the air pressure/vacuum inside the intake manifold, and the BARO tells the computer the outside air pressure. The BARO input allows the PCM to control the engine in high or low elevation or anywhere in between. This can be done other ways too, but some vehicles used BARO sensors/inputs to do this.

We have other stuff to cover that's more important than this quibble, but I thought I'd mention it anyway. My '98 does have 2 MAP sensors, maybe a '97 doesn't. One is supposedly for the PCM and one for the analog boost gage. I think.

http://www.pontiacbonnevilleclub.com/fo ... uge#p37201

If the actuator looks ok, I'd like to do another quick test for the BC solenoid itself. You have to quick swap some vac lines. I have to write it up.

Mike,.. you have been a great help for me before. There are two vids of scan readings in this thread. Presenting symptoms look like the front O2 sensor definitely isn't toggling, and is up on the Rich side limit. We got a p0440 which has to do with a failed heating unit on the rear O2 sensor. From reading the FSM, the front O2 might not go active with the PCM, if the rear one doesn't reach temperature. That's a maybe.

The bigee is the MAP reading at WOT. He's getting no visible assist from boost. It just slugs. The ignition advance is reading -20. Fuel trims are (somehow) reasonably in line. Backpressure is unlikely as he just had the a new DP and cat put on, I assuming to straighten out the problem which appeared as backpressure.

I want to finish the bypass, then I guess we start to take voltage readings.

Any thoughts are welcome.

[geofffinlay]

Agreed that the second MAP would generally be used for Baro. It's entirely possible that the PCM could use the second MAP for S/C values (alternately BARO) too, I don't know; most vehicles with a MAP, take a Baro reading @ KOEO prior to crank. By applying a little pressure to either/both and observing the changes on a scanner, we should be able to see what provides the Manifold Pressure value to the PCM.

If neither unit is capable of providing a realistic pressure value (re previous post), either the S/C isn't working (making pressure) or the MAP isn't reporting that it's working.

Just looking at the L67 engine for my Lotus, I'm guessing the following, can anyone confirm or edit for me?
Re the S/C controls. Manifold Vac pulls the diaphragm up (upper hose), which I assume closes the gate. Manifold pressure appears to force the diaphragm down (lower hose - which I assume opens the gate). The down pressure appears to be modulated/controlled via the pressure solenoid. When the PCM detects maximum allowed pressure (via MAP), it applies power (I'm guessing a modulated pulse) to the solenoid, allowing the control pressure to escape via the small orifice, thus allowing the gate position to be controlled (opened partially under load), based on preset pressure values in the manifold.

If the stuff in italics is basically correct, it would be easy to test these functions with a few basic tools.

Geoff

[Mechanical Mike]

Both MAP sensors connect to a vacuum 'T' under the supercharger snout. One side of the 'T' goes to the fuel pressure regulator, the other side goes to the first MAP sensor. The MAP sensors also have a 'T' built into them. There's a short vacuum line connecting the two MAP sensor's & a plug on the outlet of the second sensor. He could have a bad sensor, test for that by switching the wires. It's fairly common for the T under the snout to break but that would make both sensor's read zero. I suppose one of vacuum lines could have a small leak but that seems doubtful. The supercharger gasket may have failed.

[1fatcat]

As for the double MAP sensors, this can be tricky but, no GM ever used more than one MAP sensor. Some GMs used two pressure sensors and they may have even been the same part number, but they performed two different tasks and gave the PCM two different inputs.

One would be MAP (manifold absolute pressure) and the other would be a BARO or Barometric Pressure Sensor. The MAP tells the computer the air pressure/vacuum inside the intake manifold, and the BARO tells the computer the outside air pressure. The BARO input allows the PCM to control the engine in high or low elevation or anywhere in between. This can be done other ways too, but some vehicles used BARO sensors/inputs to do this.

We have other stuff to cover that's more important than this quibble,

Yes, we do...like back pressure readings...where are those numbers?

You can priech all day long, but without test RESULTS, nothing matters!

but I thought I'd mention it anyway. My '98 does have 2 MAP sensors, maybe a '97 doesn't. One is supposedly for the PCM and one for the analog boost gage. I think.

NO GM EVER USED MORE THAN 1 MAP SENSOR! If one is for a boost guage, it is NOT a MAP sensor, if one is for barometric pressure, it is NOT a MAP sensor, if one is just sitting there for looks, it is NOT a MAP sensor. Even if they are the same part number, only one of them feeds manifold pressure data to the PCM. That one, and that one only, is the MAP sensor. Your calling the boost sensor a MAP sensor.

I could abreviate a tire pressure sensor as a TPS, does that mean that a vehicle using them has 5 throttle position sensors?

I'm done with this one...good luck boys.

[geofffinlay]

I'm close to agreeing with 1fatcat. If we can't get information in a timely fashion it just wastes too much time. We don't even know if the tests are being done or will ever get done. If this isn't resolved with all the "asked for" info by tomorrow, I'll back out too.

Geoff

[charliemax]

I'm close to agreeing with 1fatcat. If we can't get information in a timely fashion it just wastes too much time. We don't even know if the tests are being done or will ever get done. If this isn't resolved with all the "asked for" info by tomorrow, I'll back out too.

Geoff

Geoff,

First, i have found your information interesting and very informative. However, it appears that something has happened of which I was not aware.

I'm a distant third party to l67poweredlss, his problem, and this board. I don't know him or represent him in any way, shape or form... and certainly have no control over flow of information. How this has morphed to my responsibility in fatcat's mind, is but a testament to someone in search of their own version of reality.

That's unfortunate, but i wanted to make it clear to you, that I am not party to your frustration over information flow.

Many of the people who come here for help, have little knowledge of their cars and even less problem-solving experience or tools,... and often time-consuming jobs, and sometimes limited free cash flow. Some people are energetic and responsive, some have a longer time scope. I bring this up, not in anyone's defense, but as a fact. I'm agreed that timely diligence would certainly show mannerly respect for the advice offered.

The obvious downside for those less responsive is, they squander the focused attention of the people helping. When they finally post milestone information, their thread pops up top of the board. At which time, they run the risk of the past assistance not being available and have to start over, explaining the entire problem.

My point being that Internet threads can't be run like an envisioned project management exercise, or it can end up like herding cats. Which I imagine could be very frustrating for you. And that would be a shame, because you have a lot to offer.

Just some perspective and expectation management offered by a very-soon-to-be American Senior Citizen, to an elder Brit in Canada. With nothing but high regard for our years and national affiliations.

Charlie

[Mechanical Mike]

NO GM EVER USED MORE THAN 1 MAP SENSOR! If one is for a boost guage, it is NOT a MAP sensor, if one is for barometric pressure, it is NOT a MAP sensor, if one is just sitting there for looks, it is NOT a MAP sensor. Even if they are the same part number, only one of them feeds manifold pressure data to the PCM. That one, and that one only, is the MAP sensor. Your calling the boost sensor a MAP sensor.

I could abreviate a tire pressure sensor as a TPS, does that mean that a vehicle using them has 5 throttle position sensors?

I'm done with this one...good luck boys.

They are identical sensors, identical MAP sensors. One for the PCM & one for the boost gauge.
Call it a boost sensor if you want. The factory service manual refers to it as a "boost/manifold absolute pressure (MAP) sensor".

[geofffinlay]

Charlie,
Thanks for taking the time to say what you did.... all of it. I found your input interesting too*. You are ABSOLUTELY NOT the target of, or the reasons for my "out" comments. I NEVER at any time considered that you were the problem getting proper responses/information from l67poweredlss. I really don't think 1fatcat is thinking any different than me.

I would say that when a person posts his problem in this format - considering the level of talent and support he HAD, FREE, at his disposal - it is simply bad manners not to do everything possible to respond promptly, presumably having followed valuable instruction. Alternately, provide a reason why it's OK for him to do some tests, not others and respond whenever it suits.

I think it's very kind of you to defend someone you don't have any connection with (that's your age sneaking through), but that's the ONLY thing so far that you and I disagree on. From my perspective he's being just plain RUDE. (CAPS are for emphasis - I'm not yelling).

I've been doing tech-support & troubleshooting for many years at the professional level. I get paid on results and any tech that knows me, wouldn't dream of calling me back with 3 bits of info when I'd asked for 6. When l67poweredlss (or anyone else) provides partial, out of context info, it's all we have to go on, so off we go, wasting a bunch of time and the less knowledgeable try a few wild guesses, which is really bush and NOT instructional in any positive way.

I don't mind being wrong from time to time. Every time I am, I learn something. The hardest thing to learn is not going off half-cocked with just a little info. Get it all first, we tend to look stupid less often that way. Let's face it, we all have our chins and I guess egos hung out here. I'm hung out just a little further than most, I'm supposed to know this stuff.

I arrived at this website looking for some specific help with a specific engine. I got that help and more. I owe it back and would prefer to pay it forward too. I do not want to have a negative relationship with anyone that has helped, or tried to help me; that includes you, 1fatcat and bunch of other members here. I'll continue to help wherever I can, but the current problem that l67poweredlss has should have been a memory by now or as your Mr Obama likes to say, "a learning moment". I'll keep my word.

*By the way, you owe us a write-up to test the BC Solenoid

I'm OK, you're OK too - just a couple of old farts!

Geoff

[l67poweredlss]

I'm sorry, I thought I posted the date of my back pressure test. I am scheduled for the test on Monday, hopefully i'll be able to make it. With snow coming i'll likely be screwed. I do apologize for not responding much. I work for Canadian Pacific Railroad and have been putting in 12-16hr days. This, plus I still shovel for my old boss when it snows. Hopefully i'll have back pressure results by Monday afternoon. You've all been very helpful so far and I want to thank you for that. Even the lead mechanics at the railroad are stumped by this. It almost feels like a House episode, only with a car. It went in storage a race horse and came out a frozen turd.

If the back pressure test comes back within spec then I will need to contact someone locally with a proper scan tool ie: Aeroforce. I have done all the tests I can do with my equipment. The SC gasket is good as I did the LIM 3 yrs ago. I also changed the SC oil and the coupler in 2005. Hopefully tomorrow morning before work I can look at the wires leading to the MAP and cross them and see what happens. The question is, if there are two MAP sensors, which one am I seeing the readouts for?

[charliemax]

.

I think it's very kind of you to defend someone you don't have any connection with (that's your age sneaking through), but that's the ONLY thing so far that you and I disagree on. From my perspective he's being just plain RUDE. (CAPS are for emphasis - I'm not yelling).

*By the way, you owe us a write-up to test the BC Solenoid

I'm OK, you're OK too - just a couple of old farts!

Geoff

Geoff,

Let me reword a sentence I was about to edit to a better precision...

I AM a party to your frustration, just not a party to its cause. My expression of it usually begins with "These kids nowadays......"

It is evident that you are a Type A and I am a Type A. More akin to giving orders than taking them. So we're going to butt heads. But that's OK, because you are a straight forward man, and behave accordingly. I don't have a need to "get along" with someone and can still respect them.

I do take exception to your misguided defense of fatcat, and the indefensible. In direct quote under my name he wrote:

"Yes, we do...like back pressure readings...where are those numbers?

You can priech(sic) all day long, but without test RESULTS, nothing matters!"

He is so uninformed and so bent for a good harassment, he did not realize it was not my car, nor my problem at hand. The "You" could have only been me. That i don't respect, nor will I put up with it.

In regard to fatcat's rant on the MAP sensor, I can leave that in the hands of Mechanical Mike and others of vetted high technical regard. The "MAP/BARO" designation is an artifact of the Series I and is not mentioned in 1500 pages of my 1998 GM Factory Service Manual - H Platform. It IS mentioned that the "MAP" sensor does take a barometric pressure, but only at ignition, and initialization of WOT. The two sensors have exactly the same pressure line input. One translates that into voltage for the PCM, the other translates it into voltage to drive an analog gauge.

I consider fatcat's unvetted tortured logic and fallacy to argument pales in a simple presentation. A presentation to which wilwren was present. With his 60,000 posts, obvious commitment to the discipline of an engineer, and years leading this site... I doubt he would leave something knowably incorrect to go unmarked. If something further has been determined, then so be it. But we go on best information available. I repeat this link for the third time... hoping that time will be taken to actually look at the photo.

http://www.pontiacbonnevilleclub.com/fo ... uge#p37201

In what will definitely be my final thoughts for this group....

I have been attempting to problem-solve based on the diagnosis diagram on Page 6-655 of the aforementioned FSM noted as "Loss of Power, Sluggishness". We have covered fuel pressure and fuel trims. We lacked direct data on the EGR. The activity of the pindle would have given us an idea if there was a back pressure issue, or the EGR was the problem itself.

Contrary to my recommendation, the crotchety 02 sensors, and the S2 O2 sensor DTC have been ignored. I was the one who originally asked for the the MAF and MAP readings, and that request lost momentum because the validity of the MAF vs RPMs was questioned. This when all we needed to know, was the air volume going in, commensurate with the pressure seen at the MAP sensor. After I (alone) took the time to analyze the data, then we either had a cause or effect situation with the manifold pressure.

At that point, we should evaluate the MAP sensor. As I was under the impression our in-need poster didn't have the meter to do that, I skipped to the Boost Control Actuator and the Boost Control Solenoid. Frankly, his explanation actually indicated questionable results. But I knew it would still show up, if I proceeded with the Solenoid.

When I need information from my senior managers, they either give it to me or tell me when they will have it to me. They "owe" me something because I make sure they get paid every two weeks. Geoff, I don't "owe" you anything because you don't pay me and you are not one of my customers. The only time I would "owe" it to you, is if I failed to deliver it on time. That failure is impossible, because the "when" I pointed out, is only after I had written it up. And there are about 1,000 things ahead of you in the line of important things in my life.

See i told you we would butt heads.

My suggestion is that you write it up. I also suggest get somebody to him with a decent scantool and multimeter. You will also need to tell him which MAP is which (cause that's next, if the boost solenoid is OK). I would be happy to do it if he is in the Phila metro area.

You also might consider your approach with a person 1,000 miles away, who has limited knowledge, limited tools, very limited problem-solving experience, and no FSM. The "what" is easy. But you have to tell them "how' to do it. Or figure out something, so you can know the "what" for him. And I am sure that has nothing to do with an "oscilloscope" which you referenced before.

My recommendation is that you somehow secure an FSM or Document ID# 47530. The section is titled
Boost Control System Check. It's several pages long and has 22 steps.

(Hold on, I almost did a fatcat flipout)

On second thought, I will meet my ethical obligation to l67poweredlss and PM my 10 minute test to him, with my recommendations for the possible outcomes. Like everybody else, he's probably workin' his butt off to put food in his mouth or on the table. And things can't be spectacular for him if he is putting hundreds of dollars into a car, which he has little chance of getting back in the open market. (At least according to Edmunds, in my area $1572) My approach was attempting to get him through this without a million dollar workup. Autozone or somebody reading the EGR, could tell him what probability there is for the cost of a backpressure test. That's the FSM speaking to probabilities, not me.

Best of luck with your problem-solving, I know you'll do great. And I'll be looking forward to posts on your progress with your Lotus Super 7 replicar.

Charlie

[1fatcat]

Charlie, I know it is not your car. I was a little upset with you because you called my info "quibble". That info was given to try to save l67poweredlss from replacing a perfectly good MAP or boost sensor or both. I even stated that the two sensor may have the same part number, meaning they could be swapped if you want to eliminate the possibility of there being a bad one.

For you to call my info quibble, after I stopped l67poweredlss from destroying his boost actuator by dumping oil into it as you suggested, is not ok with me. It is actually because of you attacking me that I don't want anything more to do with this thread. I will still give l67poweredlss advice on this if he wants it, but it will be done via PM now if he wants.

Charlie, the last time we butted heads, I still gave you advice. You ignored my advice and shotgunned parts at your car. Bypassing all tests and just guessing at a part. You claim to be wiser with age, but all I see is an ignorant, stubborn old man.
Feel free to bash the living daylights out of me now, as I will not be back on here to defend myself a second time.

[geofffinlay]

WOW Guys,
Let's ALL get a grip. I respect both of you for sticking your necks out to help a fellow traveler. PLEASE, let's back away from the place that this is going (has gone?). You gents have both tried/helped others during the time I've been looking in and not everyone's going to work out the way this one has.

Surely we can see and accept that all of the frustration expressed here, is NOT the result of our shortcomings. We collectively tried to do whatever was possible, given the only information we could get. In fact, one (or all) of us should have told the poster to get back to us when he had ALL of the information requested.

So what if an error was made in the way something was written, or even perceived? No one knows everything and some know things that are wrong! I salute everyone that has the balls to put in their 2 cents worth to help others. If that "other" doesn't know how to gracefully accept that help, then move on. After today, I'll no longer be part of this particular thread; that's what I said, that's what I'll be doing.

I do however, hope that I'll see you both contributing and helping when it's appropriate for you. The next time I'm involved in a complex one, I'll be asking for a list of equipment that's available (own it, borrow it, rent it) to the poster. The response to that will guide my involvement in that particular issue.

Best Regards

Geoff

[l67poweredlss]

Both MAP sensors connect to a vacuum 'T' under the supercharger snout. One side of the 'T' goes to the fuel pressure regulator, the other side goes to the first MAP sensor. The MAP sensors also have a 'T' built into them.

Would you mind taking a picture of the 'T"? There is nothing but an alternator wire under my SC snout.

[Mechanical Mike]

Here's a pic of the T. I totally forgot that you have an Olds not a Bonneville. You'll only have 2 MAP sensors if the Olds has a factory boost gauge in the dash. Let us know.

Let's start this thread over with what we know so far.

#1 Front O2 sensor seems to be reading very rich & rear O2 is throwing code P0141.
A- Make sure none of the spark plug wires are within an inch of the O2 sensor & wiring.
B- Start & stop the engine, remove the vacuum line from the fuel pressure regulator & look for any signs of gas in the line.
C- Unplug both O2 sensors & check for any corrosion. 2nd pic is what my son found when his car threw P0141.

#2 MAP sensor indicates low boost
A- We need to know if the arm on the boost bypass valve is moving 45 or 90 degrees.
B- I already mentioned a few things that can cause low boost but left out a couple biggies. The supercharger belt could be slipping or the PCM could be pulling boost.