Hey im wanting to update/upgrade the old worn our factory crap in my 85 GLHT but dont really know what i need aside from a vac block.
Hey im wanting to update/upgrade the old worn our factory crap in my 85 GLHT but dont really know what i need aside from a vac block.
What are your goals?
At the moment, just to update the bad factory parts. Wouldnt mind upgrading but to do what im wanting i need more money.
If i had the money id do a dodge stealth v6tt swap maybe rwd or awd with respecting engine mods for a street+track car.
www.rockauto.com
Replace what's broken.
For now, just give it a "full" T-M tune-up.
My definition of this is this: 1. first, go over the vacuum lines. They like to split, break and turn to dust when you look at them wrong, this will have you chasing your tail and wanting to do a "gas can tune-up" (pour can of gas on car, light match!). But, you'll find that many if not all of the drivability problems, mileage, etc go away once you complete this step, but you're probably very aware of this... A vacuum block might help, but until everything is "factory fresh" so to speak, I definitely would not do any "performance mods".
Also check the wiring on the back of the engine. There is a very important ground that goes from the passenger side fuel rail to the body, much weirdness will be had if it is not connected or is in poor shape (if it's running ok, it's probably fine, but it's good to know where it is and what it looks like). Also the wiring gets pretty roasted back there so you may have future wiring to attend to. The one I'd make sure is OK and still attached is the detonation sensor, it's the round deally in the middle of the intake with just one wire going to it.
Next do a "normal" tune-up. Replace the plugs, wires, cap/rotor and set ignition timing (remember to disconnect the coolant temp sensor on the side of the thermostat housing when you do!).
Run some Lucas Injector cleaner (or whatever brand you find works best for you) though it for a couple of tank fulls, replace the fuel filter after this as you may break loose crap that's been waiting to plug the filter that the cleaner will help along, otherwise you'll likely need to do it again shortly.
Install an new air filter and PCV valve.
New oil and filter.
A new, quality O2 sensor, either Mopar Or NTK will get you the best results, the cheap Bosch units will work, but many have had disappointing performance from them (I don't know why, but that seems to be the case)
This is pretty much just normal maintenance that most of our cars don't or haven't had in a long time, and you will be surprised at just how good it will run once you've got it caught up!
While you have the timing light out to set the ignition timing, set it to zero (if it's adjustable), and shine it into the inspection hole in the top of the timing belt cover, it should "freeze" the mark right in the middle of the circle. If not, check to be sure you're light is at zero, then adjust the light until it is aligned, this will tell you about how far off the guy who last changed the timing belt miss-phased your camshaft. A little bit advanced can bump up the low end and you might actually like that, but it does take away from the top end, though these engines (especially the T1 Log engines) don't have much going on up high, so that's not a big loss to most.
While you're at it, remove the two 10mm nuts holding that cover on and visually check the belt to see if it needs replacing too, these aren't interference engines, so if it breaks you won't destroy the engine like a Honda would, but it will stop you dead in your tracks...
While the cover is off, you can check the belt tension by running the car at idle (make sure the coil wire is secured out of the way), the belt should run in the middle, too far either way will indicate too much or too little tension... there's other threads that cover that as well as correcting the cam timing/phasing. In fact, Cordes (his website is in his signature above) has a number of well-done and good-humored YouTube videos that cover those very things, check them out, if nothing else they'll get you familiar with what you'll be looking at.
Once you've gotten this stuff covered, if you want to make even more power, the easiest (and safest) mod would be to install a Mopar Performance computer (also called Direct Connection in it's earlier days), there were a few floating around here for less than $100.00, possibly much less as the 85's electronics are different from all the newer stuff, but that gets a bit more complicated (changing to "modern" electronics, though Cordes does cover that somewhat too).
Best of luck!
Mike
PS Sorry for the novel, it kind of morphed into a "how to" thing and I can be a bit "thorough"!
Last edited by zin; 09-06-2014 at 08:10 PM.
"The Constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government - lest it come to dominate our lives and interests." - Patrick Henry
Bad laws are the worst sort of tyranny.
- Edmund Burke
Thanks Mike.
No problem, hope it is helpful!
Mike
"The Constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government - lest it come to dominate our lives and interests." - Patrick Henry
Bad laws are the worst sort of tyranny.
- Edmund Burke
Plug in a scanner and check for error codes.
Repair acording to any codes reported.
Do a tune up.
Change the fuel filter and check the rubber fuel hoses. Replace as needed.
Check fuel pressure. It should be around 50 psi at idle. 55 is optimal.
If you have good fuel pressure, you can start to consider increasing boost. If your fuel system is weak, you run the risk of going lean under boost. That's not good for your engine.
Best power mods for your money:
Upgraded logic module
Free flowing exhaust
2 1/2 inch swingvalve
"The Constitution is not an instrument for the government to restrain the people, it is an instrument for the people to restrain the government - lest it come to dominate our lives and interests." - Patrick Henry
Bad laws are the worst sort of tyranny.
- Edmund Burke