Need help with pinging '89TII
03-23-03, 08:55 PM
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Need help with pinging '89TII
Guys,
Specs:
100% stock '89 TII with 47,000 miles on it.
It still has all the ORIGINAL parts on it...except the brake pads.
The P.O. maintained it unbelieveably well (1000 mile oil changes etc. etc. etc., he had all the receipts)
Runs/starts/idles perfectly except the following:
1.) There is a very rare hesitation (not 3800 RPM related). About once a month it will hesitate once when lightly accelerating and then be fine for a long time. It has never happened when accelerating hard.
2.) Sometimes when I accelerate hard from a cruise (like when entering a freeway from the medium speed ramp), the boost will go up to the top of the gauge, you hear the turbo spool up (whine), the car pulls hard, then the boost and pull drop off (you hear the turbo spool down a bit and the pull lessens) and then the car starts pulling hard again and the boost gauge goes back to the top. All of this occurs in the same gear. The lessening of power and boost is very smooth as is the pickup of power afterwards. It does not do this all them time. Is this the wastegate opening up? Knock sensor? Normal?
3.) I THINK I hear it pinging on the interstate and during light acceleration (normal city driving). It will cruise fine on the interstate and start a very low (muffled) pinging sound when going up a hill (engine under load). You can't hear this at all when accelerating hard only at light throttle. Premium gas makes no difference that I can tell in this noise. Is this ping? Why only at light throttle? Most people probably would not notice this noise...I've got the stock exhaust and I listen for every little thing but it's not very loud at all. Any ideas? It's been doing this since I bought it.
I know that's long. Thanks for reading and suggestions.
Todd
Specs:
100% stock '89 TII with 47,000 miles on it.
It still has all the ORIGINAL parts on it...except the brake pads.
The P.O. maintained it unbelieveably well (1000 mile oil changes etc. etc. etc., he had all the receipts)
Runs/starts/idles perfectly except the following:
1.) There is a very rare hesitation (not 3800 RPM related). About once a month it will hesitate once when lightly accelerating and then be fine for a long time. It has never happened when accelerating hard.
2.) Sometimes when I accelerate hard from a cruise (like when entering a freeway from the medium speed ramp), the boost will go up to the top of the gauge, you hear the turbo spool up (whine), the car pulls hard, then the boost and pull drop off (you hear the turbo spool down a bit and the pull lessens) and then the car starts pulling hard again and the boost gauge goes back to the top. All of this occurs in the same gear. The lessening of power and boost is very smooth as is the pickup of power afterwards. It does not do this all them time. Is this the wastegate opening up? Knock sensor? Normal?
3.) I THINK I hear it pinging on the interstate and during light acceleration (normal city driving). It will cruise fine on the interstate and start a very low (muffled) pinging sound when going up a hill (engine under load). You can't hear this at all when accelerating hard only at light throttle. Premium gas makes no difference that I can tell in this noise. Is this ping? Why only at light throttle? Most people probably would not notice this noise...I've got the stock exhaust and I listen for every little thing but it's not very loud at all. Any ideas? It's been doing this since I bought it.
I know that's long. Thanks for reading and suggestions.
Todd
03-23-03, 09:01 PM
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Re: Need help with pinging '89TII
Originally posted by akageals
Guys,
Specs:
100% stock '89 TII with 47,000 miles on it.
It still has all the ORIGINAL parts on it...except the brake pads.
Guys,
Specs:
100% stock '89 TII with 47,000 miles on it.
It still has all the ORIGINAL parts on it...except the brake pads.
03-23-03, 09:09 PM
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Scott,
I guess I should have mentioned the following.
The plugs, air filter, fuel filter, oil and oil filter, are all new. All the regular maintenance items are new and have been regularly changed. I checked the timing, it's right on.
Todd
I guess I should have mentioned the following.
The plugs, air filter, fuel filter, oil and oil filter, are all new. All the regular maintenance items are new and have been regularly changed. I checked the timing, it's right on.
Todd
03-23-03, 09:48 PM
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Hi Todd,
The boost change you describe is very normal. My '89 T2 does the same thing. When the gauge is at the very top you're actually close to fuel cut so the factory computer turns down the boost by decreasing the duty cycle on the wastegate control solenoid. It always overcorrects and hence the car looses power as the boost falls below spec. The ECU then increaes the duty cycle on the wastegate solenoid more slowly this time bringing you back up to 'normal' boost.
I see this happen most often on cool mornings in third gear or higher. Specifically when you're holding the car in a gear and then punch it. Not so much when you're accelerating through the gears.
The factory wastegate control always favors engine safety over smooth power delivery. I don't think this is entirely a bad thing, but sometimes it's a bit overzealous.
As for the pinging, I would pull the plugs and check them anyway. Maybe some anti-seize has found it's way into the trailing plug cavity.
I had a sporadic detonation event happen to me with plugs only 4,500 miles old. I did have a lot of extended idle time on them (testing) and they just went away on me. Howver my det was under WOT acceleration, not cruise.
The best way to check for ping/det on an Rx is to hold the gear shift lever. If you feel it on the stick when you hear it LET OFF!
The boost change you describe is very normal. My '89 T2 does the same thing. When the gauge is at the very top you're actually close to fuel cut so the factory computer turns down the boost by decreasing the duty cycle on the wastegate control solenoid. It always overcorrects and hence the car looses power as the boost falls below spec. The ECU then increaes the duty cycle on the wastegate solenoid more slowly this time bringing you back up to 'normal' boost.
I see this happen most often on cool mornings in third gear or higher. Specifically when you're holding the car in a gear and then punch it. Not so much when you're accelerating through the gears.
The factory wastegate control always favors engine safety over smooth power delivery. I don't think this is entirely a bad thing, but sometimes it's a bit overzealous.
As for the pinging, I would pull the plugs and check them anyway. Maybe some anti-seize has found it's way into the trailing plug cavity.
I had a sporadic detonation event happen to me with plugs only 4,500 miles old. I did have a lot of extended idle time on them (testing) and they just went away on me. Howver my det was under WOT acceleration, not cruise.
The best way to check for ping/det on an Rx is to hold the gear shift lever. If you feel it on the stick when you hear it LET OFF!
03-24-03, 08:44 AM
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By to the top of the guage, do you mean the needle goes to where the needle is in inboost's avatar, or above it? If its above, you're overboosting and need to stop driving until you figure out why.
03-24-03, 09:39 AM
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When this happens to me in my 89 T2 the boost gauge does indeed go to the very top of the guage, but only for an instant. Then the ECU wicks it back and then it returns to approximately where it is in my avitar.
As an interesting note, this spike turns out to be a little over 9 psi sometimes according to independant datalogging I have done. This leads me to believe that the S5 fuel cut at 8.6 psi has some kind of time qualifier. For instance, "cut rear rotor when boost exceeds 8.6 psi for 2 seconds".
Here's a screen capture of what I mean:
Data Snaphot
You can see the boost went to 164kPa (9.2 psi) for a short period of time and then went to a normal 152kPa (7.5 psi). This was done in 5th gear on the freeway.
As an interesting note, this spike turns out to be a little over 9 psi sometimes according to independant datalogging I have done. This leads me to believe that the S5 fuel cut at 8.6 psi has some kind of time qualifier. For instance, "cut rear rotor when boost exceeds 8.6 psi for 2 seconds".
Here's a screen capture of what I mean:
Data Snaphot
You can see the boost went to 164kPa (9.2 psi) for a short period of time and then went to a normal 152kPa (7.5 psi). This was done in 5th gear on the freeway.
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03-24-03, 09:43 AM
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Inboost,
That sounds right on the boost change. That's exactly when I experience it....hold the car at about 3000RPM then flooring it when blending with traffic. I have not experienced the boost fluctuation when accelerating up through the gears. As for the boost gauge reading...mine pretty much reaches the max value on the guage then backs off. According to the owners manual...that's the maximum normal boost. I don't feel the ping at all...not in the stick or anywhere else. I just hear the rattle. I'd think it was not ping but it happens at exactly the times that ping would in my old Grand Cherokee. Can I unplug the narrow range TPS to see if it still pings? I once read that unplugging the TPS causes the ECU to assume wide open throttle.
That sounds right on the boost change. That's exactly when I experience it....hold the car at about 3000RPM then flooring it when blending with traffic. I have not experienced the boost fluctuation when accelerating up through the gears. As for the boost gauge reading...mine pretty much reaches the max value on the guage then backs off. According to the owners manual...that's the maximum normal boost. I don't feel the ping at all...not in the stick or anywhere else. I just hear the rattle. I'd think it was not ping but it happens at exactly the times that ping would in my old Grand Cherokee. Can I unplug the narrow range TPS to see if it still pings? I once read that unplugging the TPS causes the ECU to assume wide open throttle.
03-24-03, 11:00 AM
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Unplugging the narrow TPS, like many of the sensors, will put the ECU in safe mode. Under this condition the wastegate controller will shut down thus running the boost at wastegate spring pressure only (about 6 psi).
03-24-03, 12:13 PM
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The needle going to the very top, then going back down to where it is in your avatar is normal, i believe its the waste gate opening, but I'm sure you're not hitting fuel cut, that feels like running into a brick wall and it doesn't happen until the needle gets well above the 45 mark. As far as Todd's question goes, i was wondering if he's pegging his guage. i.e. the guage going well above the 45 mark, at least as far above as your needle is below.
03-24-03, 07:58 PM
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my old 89 TII had 3" dp and 3" mp and stock catback. IT NEVER did that. i think you might have a problem. any detonation what so ever is bad. max boost was around 10psi and dropped off to 7psi at redline. i am not sure what the problem is but i would be very careful............
03-24-03, 08:09 PM
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I would say that you had a fuel cut defensor Vosko, as this fools both the ECU and the gauge as it intercepts the signal before either device. Remeber that 450mmHg, the max reading of the stock gauge, is 8.7 psi.
If not then I would say that S5 cars don't have fuel cut at all as 10 psi is way abouve the suposed limit of 8.6psi.
I would guess that your turbo's exhuast side (turbine/housing) was stock hence the boost tapering off as you approached red line. The turbine section is a bit too small for the top end of these cars and tends to choke the engine.
You're absolutley right about the danger of detonation, we should all avoid it like the plague!
If not then I would say that S5 cars don't have fuel cut at all as 10 psi is way abouve the suposed limit of 8.6psi.
I would guess that your turbo's exhuast side (turbine/housing) was stock hence the boost tapering off as you approached red line. The turbine section is a bit too small for the top end of these cars and tends to choke the engine.
You're absolutley right about the danger of detonation, we should all avoid it like the plague!
03-24-03, 09:42 PM
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after reading your posts in teamfc3s and here i'm still thinking it is not detoniation... but i would strongly recommend you get higher octane gas... its just a safety margin.
one possible way it could be detonating is because your car has such low mileage, carbon may have built up inside your engine thereby causing detonation when little flakes of hot carbon meet the front of the air/fuel mixture being compressed.
one possible way it could be detonating is because your car has such low mileage, carbon may have built up inside your engine thereby causing detonation when little flakes of hot carbon meet the front of the air/fuel mixture being compressed.
03-25-03, 12:29 PM
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Originally posted by inboost
I would say that you had a fuel cut defensor Vosko, as this fools both the ECU and the gauge as it intercepts the signal before either device. Remeber that 450mmHg, the max reading of the stock gauge, is 8.7 psi.
If not then I would say that S5 cars don't have fuel cut at all as 10 psi is way abouve the suposed limit of 8.6psi.
I would guess that your turbo's exhuast side (turbine/housing) was stock hence the boost tapering off as you approached red line. The turbine section is a bit too small for the top end of these cars and tends to choke the engine.
You're absolutley right about the danger of detonation, we should all avoid it like the plague!
I would say that you had a fuel cut defensor Vosko, as this fools both the ECU and the gauge as it intercepts the signal before either device. Remeber that 450mmHg, the max reading of the stock gauge, is 8.7 psi.
If not then I would say that S5 cars don't have fuel cut at all as 10 psi is way abouve the suposed limit of 8.6psi.
I would guess that your turbo's exhuast side (turbine/housing) was stock hence the boost tapering off as you approached red line. The turbine section is a bit too small for the top end of these cars and tends to choke the engine.
You're absolutley right about the danger of detonation, we should all avoid it like the plague!
i have some video of it if anyone cares but back on track here. if you are detonating you might be triggering the knock sensor and it might be causing it. i would not drive it around like this. have you ever checked your timing on the car ?
03-25-03, 02:17 PM
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Vosko,
Those three days must have been a blast at that boost level!
So it sounds to me that 1989 S5 cars have no fuel cut. I say this becuase you seem to have sucessfully run a 3" down pipe and mid-pipe (eliminating all cats) on a stock ECU. In this configuration you say you ran 10 psi of boost. The 'published' fuel cut for Turbo II cars is 8.6 psi. You were able to always run above this pressure with no fuel cut defensor. You never experienced fuel cut. Do I have this all right?
As for timing, I can vouch for my car being spot on. No problems with any sensors or stored codes. It has 73,500 miles on it now and I got it with 68,000 on it. It has always behaved well, gotten good gas mileage, and has good compression. The boost is always regulated to 7.5 psi in the higher gears. Most of the time it just goes there. When I 'load' the car in a higher gear the turbo will overshoot and the control system wicks it back right away, putting it at 7.5 psi.
If I purposely set a code in the ECU on a device like the boost solenoid or trailing igntion the boost control system shuts down and I only make a solid 6 psi.
The only time my car has ever detonated was on worn out plugs (I let it idle for about 5 hours once and it destroyed the plugs! I was o-scoping various engine signals and plotting relationships. I should have shut the car off when I was crunching numbers...)
When data logging factory control signals I don't see igntion timing going away due to knock. It certainly retards more as the boost goes up, but no more or less under any condition I have put the car in.
What I do see is the duty control signal to the wastegate control solenoid increasing to raise boost and decreasing to lower boost. The facotry S5 solenoid is set so that when it's ON then boost goes up. When it's OFF boost goes down. This is becuase when it's ON it bleeds the pressure signal between the output of the turbo and the inlet of the wastegate diaphragm reducing the signal that would normally open the gate. The valve operates at a fixed frequency and increases or decreases duty cycle to change the boost level.
To sum up my opinion, the boost fluctuation is totally normal and not a concern. Detonation, pinging, pre-ignition, or misfire are all destructive to our engines and must not be allowed to continue at any cost.
My conclusion FWIW: The boost fluctuation and pinging are not related. Fix the ping, enjoy the boost!
Those three days must have been a blast at that boost level!
So it sounds to me that 1989 S5 cars have no fuel cut. I say this becuase you seem to have sucessfully run a 3" down pipe and mid-pipe (eliminating all cats) on a stock ECU. In this configuration you say you ran 10 psi of boost. The 'published' fuel cut for Turbo II cars is 8.6 psi. You were able to always run above this pressure with no fuel cut defensor. You never experienced fuel cut. Do I have this all right?
As for timing, I can vouch for my car being spot on. No problems with any sensors or stored codes. It has 73,500 miles on it now and I got it with 68,000 on it. It has always behaved well, gotten good gas mileage, and has good compression. The boost is always regulated to 7.5 psi in the higher gears. Most of the time it just goes there. When I 'load' the car in a higher gear the turbo will overshoot and the control system wicks it back right away, putting it at 7.5 psi.
If I purposely set a code in the ECU on a device like the boost solenoid or trailing igntion the boost control system shuts down and I only make a solid 6 psi.
The only time my car has ever detonated was on worn out plugs (I let it idle for about 5 hours once and it destroyed the plugs! I was o-scoping various engine signals and plotting relationships. I should have shut the car off when I was crunching numbers...)
When data logging factory control signals I don't see igntion timing going away due to knock. It certainly retards more as the boost goes up, but no more or less under any condition I have put the car in.
What I do see is the duty control signal to the wastegate control solenoid increasing to raise boost and decreasing to lower boost. The facotry S5 solenoid is set so that when it's ON then boost goes up. When it's OFF boost goes down. This is becuase when it's ON it bleeds the pressure signal between the output of the turbo and the inlet of the wastegate diaphragm reducing the signal that would normally open the gate. The valve operates at a fixed frequency and increases or decreases duty cycle to change the boost level.
To sum up my opinion, the boost fluctuation is totally normal and not a concern. Detonation, pinging, pre-ignition, or misfire are all destructive to our engines and must not be allowed to continue at any cost.
My conclusion FWIW: The boost fluctuation and pinging are not related. Fix the ping, enjoy the boost!
03-25-03, 04:46 PM
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inboost you have it 100% correct. you have no idea how carefully i tested boost control when i got the dp/mp..... i was like hey its still going WOOHOOO 
i think it could possibly be a clogged fuel injector or even bad fuel injector. if you don't have the factory shop manual download or buy one and go through it and try to find the problem
i think it could possibly be a clogged fuel injector or even bad fuel injector. if you don't have the factory shop manual download or buy one and go through it and try to find the problem
03-25-03, 06:23 PM
#20
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Originally posted by Cheers!
after reading your posts in teamfc3s and here i'm still thinking it is not detoniation... but i would strongly recommend you get higher octane gas... its just a safety margin.
one possible way it could be detonating is because your car has such low mileage, carbon may have built up inside your engine thereby causing detonation when little flakes of hot carbon meet the front of the air/fuel mixture being compressed.
after reading your posts in teamfc3s and here i'm still thinking it is not detoniation... but i would strongly recommend you get higher octane gas... its just a safety margin.
one possible way it could be detonating is because your car has such low mileage, carbon may have built up inside your engine thereby causing detonation when little flakes of hot carbon meet the front of the air/fuel mixture being compressed.
James
03-25-03, 08:07 PM
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Well....I'm still not even sure that it IS pinging that I am hearing. The noise if very faint, it can't be heard at all with the windows down, the car does not hesitate or have reduced power when I hear it.....I'm not sure what it is. One other thing...the car developed a rather loud (when cold) electro-mechanical sounding buzz that rises and falls with engine speed but not throttle. It usually goes away when the temperatures go up but this winter it buzzed almost all the time. Any ideas on that one?
Todd
Todd
03-25-03, 09:38 PM
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have you checked the codes? maybe it would give a better insight into "something"...
http://www.1300cc.com/howto/how2/codes.html
my 91 T2 has that sort of electro mechanical buzz too...but after its warmed up at idle it goes away...i thought it was just the belts...
good luck with the problem
http://www.1300cc.com/howto/how2/codes.html
my 91 T2 has that sort of electro mechanical buzz too...but after its warmed up at idle it goes away...i thought it was just the belts...
good luck with the problem
03-26-03, 08:39 AM
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Erik,
Sounds pretty much like mine. Maybe that's just normal. I goes away once the engine is warmed up now that it is fairly warm outside. I have checked the codes, it shows none.
Sounds pretty much like mine. Maybe that's just normal. I goes away once the engine is warmed up now that it is fairly warm outside. I have checked the codes, it shows none.
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