New to me 91 talon AWD

[haddixjl]

Hi Just got a clean 91 AWD talon that will probably need a motor as I was told it had low compression in #4. I haven't checked it out yet, my cousin had the 3 car for a about years and hasn't one anything with it
I got in touch with the prior owner and he told me he had put a 92+ later trans and tcase in it (I have the paperwork) reman injectors, slow boy racing stage 1 short block in it and had a local shop do the head. he also said that when he was setting the timing it never lined up right, and maybe the head or block was milled to far?

Sorry for the rambling post but I will start asking questions once I tear into this

 

[hotrodssnova]

I have had several milled heads and never had issues with lining up the timing marks.

 

[haddixjl]

ok thanks, I will start pulling it apart in a few weeks and checking it out. What could cause the marks not to line up? How many CC's are these heads factory?

 

[LarryJoe]

When you pull it apart make sure the plate behind the crank gear with the timing mark on it isn't backwards. I made that mistake when I rebuilt my bottom end. You'll never get it in time right with it backwards.

 

[haddixjl]

How do I know which way is correct? Is there a pic somewhere on here? Thanks

 

[Ghost_92TSi]

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[haddixjl]

Awesome thank you. I will check the timing first then run a compression test

Is there a picture of the plate behind the crank gear that may be on backwards? The guy said it had a problem misfiring at idle. The smog test passed at the higher rpms but failed horribly at idle like 1700ppm hc

 

[ScuzziOne]

Well, assuming that diagram is correct then you should be able to tell by the position of the crankshaft key when the plate is set at the TDC marker position. Looks like a line of symmetry drawn through the camshaft and key would be approximately horizontal (key to the leftmost extent) if the plate is correct; otherwise, the symmetry line will be significantly off horizontal (Key below the left-most extent of the crankshaft).

Barring that, the only other obvious method I can think of would be to manually bring the #1 cylinder to top-dead-center by inspection through the spark plug hole and then verify that the plate is at the TDC marker once you know the piston is at TDC.

For a plate that's been used quite a bit, it's also pretty common for the plate to show a silhouette mage of the gears each side has been placed against. Don't know if that is due to rubbing, dirt, or what but that usually makes it obvious which way the plate goes when putting it back on after a timing belt service... so, this might also make it somewhat obvious if the plate has been put on backwards at some point.

Getting the cam gears lined up properly can be somewhat of a trick when you're doing the timing belt. The trick to making it happen is to pin the timing belt to the gears wth a clamp during timing belt assembly so that forces on the crankshaft gears cannot cause them to slip position once you've got them properly positioned with respect to each other. I believe the timing belt vfaq discusses this fact and shows a picture of proper clamp placement.

And to be clear, the plate being discussed is simply the flat circular disk between the balancer belt gear and the timing belt gear. This disk has the timing mark notch cut in it and is the notch shown in the posted picture. Will be obvious once you get to it.

 

[nwBryce89]

As far as your misfire goes and failing smog I would check your plugs, wires, coil, and transistor. Also make sure your cas is not 180 out, car may run ok like this but will cause misfire and horribly fail idle test. I learned that the hard way

 

[haddixjl]

Ok I'll look into all of it. How do I tell if its 180 on these motors? I'm used to Chevy motors. I have a 91 engine manual I got with it.

 

[Ghost_92TSi]

Awesome thank you. I will check the timing first then run a compression test

Is there a picture of the plate behind the crank gear that may be on backwards? The guy said it had a problem misfiring at idle. The smog test passed at the higher rpms but failed horribly at idle like 1700ppm hc

The beveled edge faces out, I have one on the floor of my garage, I'll snap a pic when I get home but I don't get out of class till 7:30 tonight. 9hrs away

 

[haddixjl]

Cool thanks. Also what is the transitor?

 

[nwBryce89]

Your Power Transister Unit(ptu) is what it is commonly called, correct me if there other names for it, it is located just under your fuel pressure regulator mounted to your intake manifold. It is what controls tach signal and spark. Make sure the plug is on tight. If you pull your cam angle sensor out while your engine is at top dead center there is a groove and a dot that should line up on the back of the sensor if it is in its correct position, if its not just spin it 180 degress to line the groove up with the dot and reinstall.

 

[haddixjl]

Ok cool thanks I'll add it to the list of stuff to check before I tear it apart