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Discussion Starter #1
I have a 1988 Toyota Supra Turbo with a 7M-GTE engine
My friend has just replace the head on the engine because it did not hold any air compression from 4 out of the 6 cylinders. when we start it up the car has a rough idling and engine hesitates, after about a minute or 2 the engine later dies. (This did not happen before we installed the new head) When we first started up the engine after installing the new head we heard a loud high pinch whistling sound constantly but it stop 20 minutes later and we never heard that since. Now all I hear is a hissing sound like there is a vaccum leak, I check the pcv hoses and all the air intake hoses but I was unable to pinpoint the sound. If anyone has any ideas on what can be the problem please let me know. Im really stumped on this and any kind of suggestions will be helpful. I'm gonna try to upload a video of the engine running and the tachometer to my website when I can.
 

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Did you follow the manual to set the timing? change the dowel pins on the cams? have the CPS on the correct tooth?

Bob
 

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OK, then is the airflow meter plugged in? Is the accordian hose from the AFM to the turbo in good shape (they tend to craks, allowing air leaks in...unmetered air).

Finally, check the little rubber link from the 3000 pipe to the throttle. They also become brittle and tend to break on the bottom only...can't see it till its off.
 

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Discussion Starter #5
bgrieger said:
OK, then is the airflow meter plugged in? Is the accordian hose from the AFM to the turbo in good shape (they tend to craks, allowing air leaks in...unmetered air).

Finally, check the little rubber link from the 3000 pipe to the throttle. They also become brittle and tend to break on the bottom only...can't see it till its off.
I bought that accordian hose brand new 2 weeks before I put the new head in, I also checked the rubber link and they are a bit brittle, but not enough to cause the engine that rough of an idling.

But I did think I found out the problem though, I opened up the dust cover on the CPS which broke apart in pieces as soon as I opened it up and notice there was oil and antifreeze inside! :eek: I also notice that a small hose above the cps has a antifreeze leak and thats how I suspect it got in there. But I have no clue how oil got in there, I'm assuming because the old O-ring I had before was really messed up and allowed oil to come in. I'm pretty sure that would mess up the timing pretty bad but I want someone's elses opinion if it would cause the engine to misfire and die out. I also would like to know if all I have to do to fix it is to replace the dust cover and dry out any oil/antifreeze in the CPS or would that have damage the CPS bad enough where I would have to buy a new one?

Any suggestions would be appreciated :)
 

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Got Hardass?
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Oil shouldn't harm the CPS at all, it uses magnetic inductive pickups to set the timing signal. Also, if this was not working, your car would not start, period.

If it was installed incorrectly, it could give similiar symptoms. Were you sure that you installed it correctly? Getting it a tooth off, or setting the TDC incorrectly could seriously mess up the basis for the timing.

Also, the Air Fuel Meter (as stated above) could cause rough idles.

As for the whistling, get some soapy water in a spray bottle and start soaking large airflow hoses, look for bubbles or listen for the motor to stall. The lower intercooler hose is well known to break or be damages due to age, couldn't hurt to look there
 

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Discussion Starter #7
I think I found the problem.
My friend messed up big time on installing the intake manifold, he did not removed the old gasket when he installed the new intake manifold gasket. I also discovered a hairline crack on it so it has to be replaced :(. That would explain the backfiring I've been hearing also.
How much does the intake manifold go for?
 

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It's not a commonly replaced item, however I'm sure there are plenty of "project motors" and dead engines that would work well as transplants. I suggest posting a "WTB" ad in the classified of SupraForums.com and SupraMania.com
 

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Discussion Starter #10
I got my chance on my day off to replace the intake manifold, put in new gaskets, and sure enough it solved the problem and engine runs smooth now! Thank you everyone for your help and expertise! Its very much appreciated :)
 
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