BaySHO Performance
SHO Member
PFE sensor from the deleted EGR system.
Frustrated
- Thread starter SHOYAY
- Start date
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So doing some testing found I have @22hg vac at idle, drops when I rev...
Fuel pressure funky...@35psi at idle a few times, one time 50psi...each time disconnect regulator psi went up @5psi... and a few times when revving the psi would go up it would stay up and didn't come back down...when shut car off it holds around 30psi every time.
Also, when it is idleing good and I mess with pulling any vacuum hose and putting it back on, it surges then dies every time.
Fuel pressure funky...@35psi at idle a few times, one time 50psi...each time disconnect regulator psi went up @5psi... and a few times when revving the psi would go up it would stay up and didn't come back down...when shut car off it holds around 30psi every time.
Also, when it is idleing good and I mess with pulling any vacuum hose and putting it back on, it surges then dies every time.
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BaySHO Performance
SHO Member
Nothing really strange about the fuel pressure. FPR good.
When it's warmed up it idles decent, cold it surges and sometimes idles.
Big thing to me....when it's idling good and I unplug ANY vacuum line, the rpms go up a little BUT as soon as I put vacuum line back on, it stalls out and dies.
Big thing to me....when it's idling good and I unplug ANY vacuum line, the rpms go up a little BUT as soon as I put vacuum line back on, it stalls out and dies.
sperold
Last to Know
Check your Power train Control Module (PCM).
Your best option is a X2J which is the manual transmission model computer. You may have the W2Z which is the California model.
At first the code reader could not get any codes. The paper clip method seemed to jog its memory. Then it threw a pump pressure CEL. Something is up, no matter which one you have.
If it still has the W2J, who know what it does to compensate for a missing signal from the exhaust by pass, maybe it pulls the timing, or dumps in more fuel, or whatever. Or it is a X2J that has suffered somehow.
You seem to have done everything that is possible without getting into the electronics, so this would be a start on that path. It is time to swap in your 94 PCM into your 92.
Your best option is a X2J which is the manual transmission model computer. You may have the W2Z which is the California model.
At first the code reader could not get any codes. The paper clip method seemed to jog its memory. Then it threw a pump pressure CEL. Something is up, no matter which one you have.
If it still has the W2J, who know what it does to compensate for a missing signal from the exhaust by pass, maybe it pulls the timing, or dumps in more fuel, or whatever. Or it is a X2J that has suffered somehow.
You seem to have done everything that is possible without getting into the electronics, so this would be a start on that path. It is time to swap in your 94 PCM into your 92.
I'd have to pull it to see what it is but according to original owner it was sent out and remanned ...not sure which one 94 has
NoSlo
SHO Owner
Have you done the faulting firewall oxygen sensor yet? O2 sensor can give symptoms like hard missing and underpower, surging. It may cycle the CEL on and off if there is no other code. These codes are unlikely to be falsely set.
The MAF measures the air flow and adds an appropriate amount of fuel, so there is no such thing as "low vacuum" or "vacuum loss", unless something is letting in unmetered air. One source of unmetered "air" is excessive blowby gasses through the crankcase ventilation, but that won't upset fuel stochiometry since it has no oxygen (unless you left the valve cover breather tube unconnected), it will just displace intake airflow.
It is normal for engine vacuum to drop when you open the throttle and allow airbox air in.
The engine has to learn replacement management parts, you can't just pop them in and expect immediate results. It is best to adjust the TPS to 0.95 volts at idle position, and then do an idle relearn (by disconnecting the battery with lights on for 10 minutes), and then when you first restart the car, let it idle for at least two minutes, then turn on AC and turn wheel for another minute, all without touching the gas pedal, and then take it for a short drive.
The throttle position sensor and oxygen sensor are there to anticipate and fine-tune the fuel mixture.
The MAF measures the air flow and adds an appropriate amount of fuel, so there is no such thing as "low vacuum" or "vacuum loss", unless something is letting in unmetered air. One source of unmetered "air" is excessive blowby gasses through the crankcase ventilation, but that won't upset fuel stochiometry since it has no oxygen (unless you left the valve cover breather tube unconnected), it will just displace intake airflow.
It is normal for engine vacuum to drop when you open the throttle and allow airbox air in.
The engine has to learn replacement management parts, you can't just pop them in and expect immediate results. It is best to adjust the TPS to 0.95 volts at idle position, and then do an idle relearn (by disconnecting the battery with lights on for 10 minutes), and then when you first restart the car, let it idle for at least two minutes, then turn on AC and turn wheel for another minute, all without touching the gas pedal, and then take it for a short drive.
The throttle position sensor and oxygen sensor are there to anticipate and fine-tune the fuel mixture.
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NoSlo
SHO Owner
You use a multimeter, connect negative probe to ground, and with ignition on but not running, poke into the back of the TPS connector and find the pin that measures around one volt. Loosen the two screws and twist until the reading is 0.95V and tighten back up. On some this may take enlarging the screw holes, on others, you'll already have the correct reading. If it is too high, the ECU may think you have your foot on the pedal.
If you don't want to buy another O2 sensor for the obvious fault, but instead have lots of time, you can swap the oxygen sensors front-to-back, and see that the 172 code changes to a 176. Then at least the problem sensor will finally be on the front where it is easy to change.
Engines like to maintain their vacuum. If you pull a vacuum line, you are letting a lot of unmetered air in, making the engine go lean. It probably then tries to figure out what the **** is going on to try to keep the engine running and maintain idle, such as closing the IAC, and then you go and stick the hose back on again.
Just for giggles, clean the IAC. Soak both of the openings in carb cleaner, and let it stew, and then dump out the carbon and oil. Also spray the electrical contacts clean. If this control is reluctant, the idle speed can't be maintained, which is a little different than your main symptom, which can definitely come from O2.
We assume that you've checked for idiot problems, good spark plugs and wires and no oil in the plug wells. Changed your fuel filter. You could have something as completely unrelated to your haphazard troubleshooting as a glitchy coil or crank sensor, or even ECU ground wire. Check fuses for engine controls, like the heater power for O2 sensors. Even something as bizarre as a blown alternator regulator can make for glitchy overvoltage when you rev up the engine.
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I'll try that with the tps. I have changed over tps, iac,maf, from a good running parts car. New fuel filter. Motor has 10k since rebuild so plugs, wires etc are all relatively new, just put another set of new plugs in too.
When revving the engine from under hood, I think I hear clicking from around the ccrm area, sounds like 3 quick clicks. Hard to tell exactly where cause it's a little loud at the moment cause there's a bit of an exhaust leak from the y-pipe gasket.
And when test driving, it totally sounds like there's a noisy collapsed lifter ticking noise on acceleration and not there on deceleration or when putting any load on the engine just to move it.
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BaySHO Performance
SHO Member
That may be rod bearings. Try to pinpoint where the noise is coming from.
Needing rod bearings with only 10k on engine?! Oil pressure is great, 60psi cold idle, 20 hot idle
BaySHO Performance
SHO Member
Must be something else, then.
I try to upload a vid of the noise but always says too big a file.
The noise is most pronounced on acceleration or engine under load... disappears on deceleration... slightly there revving from idle
NoSlo
SHO Owner
That totally sounds like a bottom end bearing, heard from inside the passenger compartment. You first video shows the sound lessening when the engine is unloaded between shifts. Sorry.
It can sound like it is coming from elsewhere, a recent thread saw the owner opening the top and front, only to finally find the spun rod bearing. The tick of a rod bearing is transmitted into the rod and piston, and into the crank. You need to roll it up on ramps and get near the oil pan to not be deceived.
Cam chain tensioner sounds like you'd expect a belt slapping around to sound. A valve that shot out a shim, making a cam tap, or is wedged, hitting on the piston carbon that could also sound like that are long shots. These wouldn't care how much gas you gave the engine.
(The flappy slappy of an ATX timing tensioner is a sound I also hope not to hear again...)
A wishful far in left field is you got terrible octane gas or mixed with diesel, and a high compression cylinder from carbon etc, along with a bad knock sensor...and maybe slipped a timing belt tooth or poor injector.
It can sound like it is coming from elsewhere, a recent thread saw the owner opening the top and front, only to finally find the spun rod bearing. The tick of a rod bearing is transmitted into the rod and piston, and into the crank. You need to roll it up on ramps and get near the oil pan to not be deceived.
Cam chain tensioner sounds like you'd expect a belt slapping around to sound. A valve that shot out a shim, making a cam tap, or is wedged, hitting on the piston carbon that could also sound like that are long shots. These wouldn't care how much gas you gave the engine.
(The flappy slappy of an ATX timing tensioner is a sound I also hope not to hear again...)
A wishful far in left field is you got terrible octane gas or mixed with diesel, and a high compression cylinder from carbon etc, along with a bad knock sensor...and maybe slipped a timing belt tooth or poor injector.
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