Rocker adjustment....

Topic: Rocker adjustment.... (Read 28272 times) previous topic - next topic

Rocker adjustment....

Reply #165 – November 13, 2014, 05:36:27 PM

I'll post the cam specs when I get home tonight. I am hoping for a vacuum leak somewhere. Everything worked great until those parts were swapped.

Rocker adjustment....

Reply #166 – November 13, 2014, 05:37:24 PM

The MAP sensor........how do you check that with a meter?

Rocker adjustment....

Reply #167 – November 13, 2014, 06:52:04 PM

Quote from: vinnietbird;440570

The MAP sensor........how do you check that with a meter?

You'd probably have to google it, but obviously, it is a BAP sensor on your car, not MAP. It shouldn't have too big of an impact on a mass-air system, but a sensor is still a sensor.

You can pull the o2 sensors - just tuck the wires up some place. You will likely turn the plugs temporarily black with your drive home - it doesn't take long. I'm almost certain you will see that it drives the way you expect, without pops (according to your previous information).

This is where diagnostic equipment really CAN save you time and money in the long run. Swapping parts is annoying! Anyway, wideband would help, but it may not help as much as Tom thinks - the EEC will compensate, and if the o2's are still switching, the o2 will show ~14.7:1. You may have one bank that is failing to go into closed loop due to a lean mixture - when this happens, the EEC will use the working sensor's readings to control the fuel trim of both banks. Such a problem would lead me to believe one or more runners for one bank of the motor have a vacuum leak.

Rocker adjustment....

Reply #168 – November 13, 2014, 07:28:00 PM

Quote from: vinnietbird;440569

I'll post the cam specs when I get home tonight. I am hoping for a vacuum leak somewhere. Everything worked great until those parts were swapped.

Did you mess with the O2 sensor harness at all during the swap?

Without the smog pump hooked up, you should see codes 44 and 94 while running a KOER test. This is normal with no smog pump and is confirmation that the O2 sensors are in fact working.

Rocker adjustment....

Reply #169 – November 13, 2014, 08:04:17 PM

Quote from: V8Demon;440573

Did you mess with the O2 sensor harness at all during the swap?

Without the smog pump hooked up, you should see codes 44 and 94 while running a KOER test. This is normal with no smog pump and is confirmation that the O2 sensors are in fact working.

If both o2 sensors were bad, he would remain in open-loop. Since the EEC will switch to closed-loop after 100-seconds on a warm start, which coincides with his remarks about it running well for about "90 seconds", the EEC believes at least one of his o2 sensors is good. It starts off rich, begins to slowly lean out the mixture of both banks until the o2 pegs full-lean, then slowly richens the mixture until the sensor shows richer than 14.7:1 again. If one o2 sensor is bad, it will perform the slow richening, then slow leaning-out a second again before marking one o2 sensor as failed, and begins to use the good one for fuel trims on both banks. I know it won't go into closed-loop without any sensor plugged in, but I haven't observed the AFR behaviors when this is happening so I can't comment on those.

The EEC will only compensate for a tune that's off by 12.1% lean or rich. Any more than that, the stock tune will not compensate further. Vinnie may have one, or both, banks outside of this adaptive range. A vacuum leak may make one bank reach its full 12% richening, and still be running lean. Reasons could be many. A KOER test will of course show a bad sensor. Slow/old o2 sensors shouldn't have too much of an effect on hitting the limit of the adaptive system.

Shooting for 14.7:1 in closed-loop but being one point leaner at 15.7:1 would cause the motor to run very poorly. Shooting for 11.6:1 in open-loop, but reaching 12.6:1 actual would make the NA motor feel like it has great power. All of this can typically be seen with a $150 wideband that Tom is suggesting. That's a good $200 in parts and bung installs that Vinnie may not have atm. Diagnosing things can get expensive. I hope we can help him narrow this down without buying hundreds/thousands of dollars in gauges and other parts/labor. They are good tools to have on hand though.

There are many other variables in how the EEC decides AFR, but this illustrates why open loop "could" run well while closed-loop had problems.

Rocker adjustment....

Reply #170 – November 13, 2014, 08:19:33 PM

He can read the O2 sensors with a meter if he likes while driving the car. If he is stock he has a MAP. Is he modified in this regard. Once again he needs bacic trouble shooting and basic plug readings. Or at least a wide band to shoot this lean condition.

Is pin 49 grounded properly on the ECM. Normally it goes to the manifold near the DIZZY. Just a stretch but check it

Rocker adjustment....

Reply #171 – November 13, 2014, 08:28:15 PM

The cam specs are as follows....

0.573 in. 0.557 ex. lift at valve

215 in. 223 ex. duration

Didn't get to unplug the O2 sensors. Bloody dark after work. Hospital work can SUCK !!! Never know when you're ACTUALLY getting off work. Anyway, I'll do my best to do what I can. Can't get to a mechanic shop for quite some time due to my hours Monday through Friday. Not off any weekdays anymore. Everybody is closed when I go to work, closed when I get off.

On to the car. When I press the throttle, it hangs a wee bit, Not instant rpms. Like a quick pause then the revs. And it can take a second to come back down

Rocker adjustment....

Reply #172 – November 13, 2014, 08:29:16 PM

What is the LS numbers of the cam?? Cam sounds Ok for your ECM

You have an 88 so you should have a MAP. Unless CALIFORNIA. Is your California emissions???

Depending on it's configuration, it's either a MAP sensor ('86-'87 and '88 49-state) or it's a BP sensor ('88 CA only, '89+ 50-state). You should have a MAP. Once again someone posting wrong info. unless you are modified. Not sure if you are.

You need basic tests as i explained. Start with the basics > Compression fuel pressure leak down idf possible and a smoke test. Without the basics out of the way you are chasing balloons. Best thing is a wide band for AF numbers. Good luck my friend you are most likely Closed loop lean' Hang in buddy

Rocker adjustment....

Reply #173 – November 13, 2014, 08:43:26 PM

Quote from: TOM Renzo;440577

What is the LS numbers of the cam??

You have an 88 so you should have a MAP. Unless CALIFORNIA. Is your California emissions???

Depending on it's configuration, it's either a MAP sensor ('86-'87 and '88 49-state) or it's a BP sensor ('88 CA only, '89+ 50-state).

Vinnie has the 1988 Tbird in his signature, converted to mass air. That sensor is acting as BAP.

Vinnie, you left the vacuum hose off of the BAP sensor, correct?

The throttle issue initially sounds like a vacuum leak also. It COULD be tps, but vacuum leaks will allow more air into the engine, making it take longer to spin up (get rid of the excessive lean condition), and less vacuum available to drag the motor down. The IAC will smooth out the dropping idles as it approaches idle though. Of course, a larger TB than the EEC expects will also make the TPS values matter less - the TB is already allowing in more air than the TPS would suggest it is. Mass air cares more about the MAF though.

My initial thought is again, vacuum leak. Still doesn't explain black smoke at lower base timing, but one thing at a time...

Rocker adjustment....

Reply #174 – November 13, 2014, 08:52:28 PM

SO! Seek yopu are talking Vacuum leak and said a wideband is not in the MIX. That is news to me. How would you explain that??? I am all ears because when tuning a Wide band is Mandatory. No tuner will tune without one PERIOD. How do you know where you AF is???. I did not know he was mass air. maybe he has a vacuum line connected to the MAP BARO. Got it he is MASS AIR. I never red his build EXCUSE ME!!!!!!!!!!!!!

He is closed loop lean . All his symptoms lean twords a lean condition. Without a wide band he is chasing BALLOONS. He is modified and absolutely needs AF readings to fix this condition. Just me could of course be dead wrong SEEK But i do not think so Thoughts SEEK. By the way a to big Throttle body acts like a to big CARB. To much air and not enough engine. Sometimes people build in Troubles. Do we agree on that. Now i would suggest for whatever it is worth to do basic trouble shooting and checking with smoke for vacuum leaks. Do we agree on this YES NO???

If he has an adjustible fuel pressure regulator he can crank up the pressures and leave the vacuum line disconnected to see if he needs more fuel. simple tests like this cost nothing and can help if he does not have access to a dyne or an AF reader. If he cranks up the Fuel pressures he can determine if he is in fact LEAN. Also he can monitor or trick the O2 sensore rich and see what happens. modifying an engine especially a OBD1 ford is not for the novice. I spend endless hours on the dyne tuning the dinosures. naturally a Stand alone is the ticket ,But expensive, And of course he just might have more air then he needs for that engine and needs to down grade his TB. just a thought

Rocker adjustment....

Reply #175 – November 13, 2014, 09:19:56 PM

http://www.ebay.com/bhp/wideband-air-fuel-meter

Rocker adjustment....

Reply #176 – November 13, 2014, 09:33:25 PM

A wideband o2 sensor is much more sophisticated than a narrowband sensor, and can be relied upon to be used as a tuning tool. Wideband sensors not only are a lot faster acting in the reading, but can tell you the exact a/f ratio that the motor is currently at. So instead of just telling the ECU that the motor is running rich, it will read a voltage that correlates to an actual value, like 11.2. One thing to remember with a wideband sensor is that it has a heating element that needs to be heated up before the sensor will be accurate in its readings. This usually only takes a few seconds, but just remember that for those first few seconds the gauge is not useful. Wideband sensors give the ECU the ability to tune exact A/F value’s to a tenth of a decimal instead of just richening and leaning the mixture till a stoic value is seen.

Rocker adjustment....

Reply #177 – November 13, 2014, 10:34:50 PM

Tom, lobe separation is 111.

I have mentioned it smokes a bit. Looks like a dark gray maybe. Hard to tell on the road, tinted windows, and traffic. That's only under hard acceleration. Not under normal driving at all. The throttle body is a 70mm.

SEEK, yes, Sir, I left the vacuum off ages ago when i converted it to Mass Air. I got my NOS Motorcraft TPS today. It'll go on (simply because the one I put on for now was over 20 years old), and it certainly can't hurt anything.

I appreciate all the time and effort you guys. More than you know. But no conflict please. I'm seeking ideas to figure this out, as simple as possible due to the lack of Mechanic shop equipment and such.

Tom, I wish I had the means that you do to build cars, mod them, check them out and the rest, but my reality isn't yours. It sucks, but it's true. Not one single penny from my paycheck ever goes into this car. Big limitations, so as you can see, I'm on a much smaller budget.

Rocker adjustment....

Reply #178 – November 13, 2014, 11:16:36 PM

I don't think Tom and I are looking for different things - I know he simply doesn't follow this build, or look into the details or this specific combination. FOr example, we don't even know which gaskets have been used - there are certain ones that seem to simply not seal well. I don't know how flat all the gasket mating surfaces are - as I mentioned in another thread, my new accufab throttle body came not-quite-flat at the IAC. Vinnie has stated what tools he has and the limited budget. Recommending a wideband for someone is pointless if they won't buy one.

Tom, can you provide suggestions to Vinnie that do NOT require buying various tools? Yes, a wideband would show a lot into what is going on (preferably a bung on both sides of the exhaust so you can check both banks). A wideband may show lean, but then you have to go to the next tool purchase to start narrowing it down. It doesn't matter to recommend something if it won't be purchased. What can Vinnie do with the car he as now, AS IT IS, without buying more tools? I'm all for buying the right tools for the job. I have way too many tools in my garage for a hobbyist, but I understand the usefulness of them all. Suggesting them in this thread I think is fine, but the purchases won't happen, so let it go. He has a compressor - he can check for leaks by using a hose barb attached to the line going to the vacuum tree, and the right threads/adapters for attaching to his compressor's hose. Feeling around for air escaping can help pinpoint a leak. Using something like baby powder, "poofed out of the container to create a floating dust" around all gaskets will show turbulence if there is a leak. I don't think you want to try more than 30psi - I don't know how much pressure the gaskets can take. There is no "pressure equivalent for 20inches of vacuum" - they are different measurements.

What else can Vinnie do as a "backyard mechanic" to help him pinpoint causes of various problems? That is the most help that we can get Vinnie in this thread. Until a budget allows or Vinnie finds some local friends with shop tools, talking about widebands, smoke machines, leakdown tests, or even a simple compression gauge is useless if there isn't currently a budget.

My suggestions:
- Unplug o2's and see if problem goes away. If it does, we know it isn't something else completely unrelated. It gets us some data.

- To prevent damaging your factory harness, see if you can find a cheap o2 extension harness to install between the o2 and existing harness, and tap into the signal wires any way you can. Run wires, tapped into the o2 harness, into the cabin and use a voltmeter to see what voltage they read. I'm guessing you will see under 0.4V consistently on at least one bank when the issue starts to occur, in closed loop, indicating a lean AFR. If this is only one bank, it will help point to the next item to look for. 0.3V constantly would be a really bad lean AFR.

- Hook up compressor to vacuum hose going to vacuum tree and cap off throttle body. Pressurize intake and blow some type of powder around the outside of the motor. Watch for any weird movement of the powder, around egr blockoff, iac, tb, intake, injectors, upper to lower intake, lower intake on all sides (including front/rear where the rtv seals between the rubber and gasket, valve covers, and even the oil pan, front/rear seals, timing cover, oil level sensor, dipstick. The entire system, with the rocker arms on, should be pretty sealed. Leakage into the cylinders, past the rings, into the combustion chamber should still seal relatively well. You can back off all the rockers and disconnect the fill tube hose to get the crankcase out of the equation, if your pcv is good. You can also check the vacuum lines, although less likely to be a problem. Don't forget any plugs you have in the intake - mine are rtv'd on the threads. Basically, any place the motor could suck up unmetered air - even the oil dipstick, with all of its twists and turns, is still a small vacuum leak since it allows air in, up through the head's oil drain holes, through the fill tube to TB hose. Leaks down in the crankcase are unlikely to change the AFR any detectable amount though.

- Set timing to 10 degrees for further steps. I wouldn't try to fix a problem with the timing adjusted to fix a potentially different issue. You may also want to try this with the o2 sensor step above. See if one bank is going rich, and causing all the smoke at WOT

That's all I can suggest at the moment, for what we know, and what tools are available. Further data gathering is needed. Since this is a daily-driver, that makes testing things a bit more annoying. You can't simply test some things with parts removed, then come back later to test more/where you left off. The above can all be tested without making major changes to the vehicle - the car could be put back to where it was and driven in the matter of minutes (minus exhaust temperatures).

As you get a heavily modified engine, the need for a tune really does increase. Technically, this motor should be tuned. It is possible to ballpark the thing though, easily leaving up to 10% of the potential power still on the table. The computer never learns/adapts WOT fuel trims, since the o2's are always pegged rich. A wideband and tune is needed for that. Accurate mass air (basically, aftermarket accuracy is rarely good) readings also matter a lot (but not for this closed-loop issue). This is also why I am going Lightning 90mm sensor - not a high-flowing meter for its housing size, but it has good accuracy (when plumbed in correctly).

Rocker adjustment....

Reply #179 – November 14, 2014, 03:53:09 AM

Seek, I was wondering if perhaps his O2 sensors were switched and now reading g the wrong banks.