North American Turbocoupe Organization



Camshaft 180 degrees off? Is that possible
94VERTiGO Offline
Junior Member
#1
So, my newly acquired 88 turbocoupe will not boost past 10 and the revs would not run out past 4500RPM.  I confirmed the fuel switch is in PREMIUM so the turbo should spool up past 10.  The car also overheats.  The gauge goes past H, but it will drop below H as if the thermostat is cycling.  When I purchased the car the PO stated that he had changed the timing belt at 60k miles, and he mentioned something about possibly off-setting the cam gear a tooth or 2 to gain more performance.  So, I decided to check the timing of the cam against the crank pulley and see where it was.  Turns out the cam gear was 180 degrees off.  I wouldn't think it was possible to run an engine with the cam 180 off.  I put the crank at TDC prior to pulling everything apart to see the cam gear.   The cam gear should be at the bottom with the crank at TC, but, the pointer is at the top.   
Would running an engine with the cam 180 off cause overheating? I tried to post a picture but it is more that 1024K so it won't post. 
Thanks
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firebirdparts Offline
Member
#2
You will find 100,000 internet posts on having the camshaft 180 degrees out, but there's no such thing.  No matter who tells you its real, don't listen.  The cam gets 180 degrees "out of time" and then comes back "in time" with each crank rotation.

Some alternative explanations to having it overheating might be that the ignition timing is a little behind.  The suggestion that you were 1 tooth off certainly made sense.

What year is your car?  If you have original computerized boost control, then you should not have over 10 psi boost until you get over 4500 rpm, and you claim you haven't done that.  So the whole 4500 rpm thing needs to be figured out.
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Mikey97D Offline
Member
#3
I will echo firebirdparts comments, turn the motor over one rotation and the cam and TDC should be close to lining up to the marks. That will let you know if the cam is timed/aligned to the crank correctly.

I don't believe the boost and 4500 rpm are connected unless you have a vacuum leak (needs to be checked on these old cars). My vacuum lines were in very bad condition from the boost controller on the passenger inner fender to the turbo and waste gate diaphragm actuator (CRS moment and can't remember the name of that thing). I wouldn't try increasing the boost until you have the overheating and rpm stuff figured out.

Do you hear the motor pinging? How much vacuum do you have at idle? Is the cam pulley lining up after rotating?
Turn the ac on to see if the radiator fans turn on?
1988 TC, 5 spd, Stinger 3" Exhaust, Schneider Roller Cam, -4° Cam Pulley, Cone Filter, Gilles Boost Control Valve set at 17 psi, CHE Rear Lower and Upper Control Arms, Braided Brake Lines, Hawk HPS 5.0 Front and HPS (F) Rear, CRES Inserts in front calipers, and '93 Cobra Wheels with General 235/50R17 Tires.   
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94VERTiGO Offline
Junior Member
#4
Firebird and Mikey, 
Thanks so much for the input.  

I had rotated the camshaft 180 deg because I thought it was 180 off, I will return the cam to its original position and spin the crank around 1 more time to ensure they line up...the second time around... 

No motor pinging, idles smooth up around 1000rpm maybe a little high.  The A/C does not work when I turn it on, nothing happens, no A/C clutch engagement, no fans come on.  

The car is an 88 model.  I wasn't aware that it would not boost past 10psi while under 4500 rpm. 

I will double check vacuum lines and put a timing light on it and see what the base is set at with the spout disconnected. 

I will report what I find thanks again for the advice.
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Mikey97D Offline
Member
#5
(07-25-2019, 06:09 PM)94VERTiGO Wrote: The A/C does not work when I turn it on, nothing happens, no A/C clutch engagement, no fans come on.  

One or both fans should come on when you turn the AC on.  Does it run hot going down the road or just sitting idle in the driveway?  (Not sure where you are roadwise with the car)
https://turbotbird.com/old/techinfo/Cool...ingFan.htm

And just in case you need to disassemble the AC clutch fan
https://turbotbird.com/old/techinfo/ac_c...sembly.htm

Timing Belt for reference:
https://turbotbird.com/old/techinfo/CamT...t%20Up.htm

I believe all these articles have been converted by Andrew into the new FAQ forum.  I just saved the old spot so not sure how long they will be available.

Does the car still have the bottom valence (black) under the front bumper?  The '87-88 are bottom breathers so they get all the cooling from down under the bumper and need that valence to scoop air through the radiator.
1988 TC, 5 spd, Stinger 3" Exhaust, Schneider Roller Cam, -4° Cam Pulley, Cone Filter, Gilles Boost Control Valve set at 17 psi, CHE Rear Lower and Upper Control Arms, Braided Brake Lines, Hawk HPS 5.0 Front and HPS (F) Rear, CRES Inserts in front calipers, and '93 Cobra Wheels with General 235/50R17 Tires.   
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JT Offline
Posting Freak
#6
(07-26-2019, 12:19 PM)Mikey97D Wrote:
(07-25-2019, 06:09 PM)94VERTiGO Wrote: The A/C does not work when I turn it on, nothing happens, no A/C clutch engagement, no fans come on.  

One or both fans should come on when you turn the AC on.  Does it run hot going down the road or just sitting idle in the driveway?  (Not sure where you are roadwise with the car)
https://turbotbird.com/old/techinfo/Cool...ingFan.htm

And just in case you need to disassemble the AC clutch fan
https://turbotbird.com/old/techinfo/ac_c...sembly.htm

Timing Belt for reference:
https://turbotbird.com/old/techinfo/CamT...t%20Up.htm

I believe all these articles have been converted by Andrew into the new FAQ forum.  I just saved the old spot so not sure how long they will be available.

Does the car still have the bottom valence (black) under the front bumper?  The '87-88 are bottom breathers so they get all the cooling from down under the bumper and need that valence to scoop air through the radiator.

If the A/C compressor does not turn on, as the OP stated, then the fans also won't turn on with the A/C switch. The fans will simply operate based on engine coolant temperature.

Before diving into the Cooling Fan System (unless it actually is running hot and not just the normal factory gauge inaccuracy at play), checking the freon level in the A/C system would be a good idea because if it's too low or empty then the A/C compressor won't engage nor will it turn on the fans with the A/C on.
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firebirdparts Offline
Member
#7
My car also shows a little hot on the temperature gauge when I stop moving. I don't like this, but it hasn't done any harm. I checked my fans and they do come on, they just come on after the gauge is up there where I don't like it.

I did find this website's explanation of the fans (two stage) to be very helpful and mine do work. I have no freon in the a/c so they don't work when the a/c is on. There was at least the suggestion here on the club website that the temperature seen by the computer and the temperature seen by the gauge might be in disagreement because of hte senders. One might be wrong.

It also occured to me that you could have some sort of air/fuel issue that occurs when you hit 4500 rpm and the boost tries to go up. The way the system is set up, that would not be an obvious thing to happen. You may want to check your boost valve and see just what you do have there and whether it's plumbed up correctly. If it is, then the next question more or less has to be wether it actually works. When it's just sitting there doing nothing, you'd be limited to 10 psig.
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Jeff K Offline
Administrator
#8
If you are going to up boost and make other mods, especially with the stock EEC IV PCM, a wideband O2 is almost a necessity so you can see what is actually going on.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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anasazi4st Offline
Senior Member
#9
(07-27-2019, 09:44 AM)JT Wrote:
(07-26-2019, 12:19 PM)Mikey97D Wrote:
(07-25-2019, 06:09 PM)94VERTiGO Wrote: The A/C does not work when I turn it on, nothing happens, no A/C clutch engagement, no fans come on.  

One or both fans should come on when you turn the AC on.  Does it run hot going down the road or just sitting idle in the driveway?  (Not sure where you are roadwise with the car)
https://turbotbird.com/old/techinfo/Cool...ingFan.htm

And just in case you need to disassemble the AC clutch fan
https://turbotbird.com/old/techinfo/ac_c...sembly.htm

Timing Belt for reference:
https://turbotbird.com/old/techinfo/CamT...t%20Up.htm

I believe all these articles have been converted by Andrew into the new FAQ forum.  I just saved the old spot so not sure how long they will be available.

Does the car still have the bottom valence (black) under the front bumper?  The '87-88 are bottom breathers so they get all the cooling from down under the bumper and need that valence to scoop air through the radiator.

If the A/C compressor does not turn on, as the OP stated, then the fans also won't turn on with the A/C switch. The fans will simply operate based on engine coolant temperature.

Before diving into the Cooling Fan System (unless it actually is running hot and not just the normal factory gauge inaccuracy at play), checking the freon level in the A/C system would be a good idea because if it's too low or empty then the A/C compressor won't engage nor will it turn on the fans with the A/C on.

Agree 100%. If there is no A/C clutch engagement then there will no fans, they will operate as normal.

Harbor Freight sells a good set of gauges for $60. While some might argue that they are not the same quality as a $200 set, I will say I have used mine repeatedly since 2014. For that price my math tells me I could buy 3 for $200, should this one fail (they have a 1 year warranty.)

There are various articles here and on the Internet that will show you how to use them. Just remember to TURN OFF THE HIGH SIDE VALVES if you are going to charge the Freon from a can, it will explode in your face (no, I don’t know this from personal experience).

If you still have R-12 there is an excellent article here on conversion to R-134a. I converted mine in 2014 and it runs cooler than either my wife’s PT Cruiser (not a surprise) or our 4Runner; and it gets over 100 here every day in the summer, usually 110.
Another proud dues-paying member.

1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 1 T5OD full rebuild, 5 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
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anasazi4st Offline
Senior Member
#10
(07-27-2019, 12:51 PM)firebirdparts Wrote: My car also shows a little hot on the temperature gauge when I stop moving.  I don't like this, but it hasn't done any harm.  I checked my fans and they do come on, they just come on after the gauge is up there where I don't like it.

I did find this website's explanation of the fans (two stage) to be very helpful and mine do work.  I have no freon in the a/c so they don't work when the a/c is on.  There was at least the suggestion here on the club website that the temperature seen by the computer and the temperature seen by the gauge might be in disagreement because of hte senders. One might be wrong.

It also occured to me that you could have some sort of air/fuel issue that occurs when you hit 4500 rpm and the boost tries to go up.  The way the system is set up, that would not be an obvious thing to happen.  You may want to check your boost valve and see just what you do have there and whether it's plumbed up correctly.  If it is, then the next question more or less has to be wether it actually works.  When it's just sitting there doing nothing, you'd be limited to 10 psig.
 
Be aware that more than a few of the newer sending units give inaccurate readings. When I replaced my head gasket several years ago I decided to go with most everything new—temp sending unit, anything that was more easily accessible whilst the engine was apart. To my dismay the temp gauge now topped out near the top, when before it was halfway down when the fans came on.

I drove home during this first test drive at 15 mph, terrified that I had done something wrong in reassembly. I replaced the sending unit with a few other new ones from various sources, same results. I put the first one back on, it was back to normal. I then used an infrared thermometer to measure the coolant temp, it was fine. The sending unit was accurate.

**Also echo the thought that the engine should not run at all (or very poorly) if the camshaft is off 180 degrees. The engine would be attempting to vent the exhaust gas through a closed exhaust valve and receive air-fuel mixture through a closed intake valve.
Another proud dues-paying member.

1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 1 T5OD full rebuild, 5 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
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