GoldenRexasaurus[fc]

Hi im new to doing anything with an rx7 and also have little time to fix up my rx7 due to college and all, but last week i took it in for a diagnostic and they said I need to replace the upper intake gasket.
Seems like something i can do but i will have to note down what i do to put everything back correctly.
Or is there things that i need to know before i do anything? Should I get a mechanic or someone who knows alot about cars to do it?

Jager

iTrader: (10)

Double check your TPS and make sure everything is plugged back in the way you got it.

My5ABaby

iTrader: (7)

Is your car acting funny? Telling you to replace the UIM gasket is kind of a random thing to tell you.

Did you take it to the dealer? If so, ignore whatever they said

Taking off the UIM (upper intake manifold) isn't very hard to do. The hardest part is the vacuum lines because they're easy to confuse.

Considering it's your first time, I would color code everything (or some other type of system). Such as, if you take a vacuum line off, mark the vacuum line with a color, then mark where it connects to with the same color. You can use little colored stickers, paint (something crappy that will just stay on there temporarily), etc...

There's also probably a diagram on the hood of you car to show you where the vacuum lines go. Additionally, the FSM and Hayne's manuals both have diagrams.


While you have it off, I'd replace the vacuum lines, fuel lines, and check basically everything you can see. There's a coolant hose on the backside of the UIM (by firewall) that has a tendency to leak over time. That's something good to check.

GoldenRexasaurus[fc]

Thanx for your reply,
Well when i took it in for diagnostics(not at the dealership, i had it done at a autoshop->bumber2bumber), he said air was leaking out.
When I drove half way to the shop it was fine, but the rest of the way everytime i stepped on the gas pedal it wouldnt do anything at all, only rev up and down. The engine starts up fine but even now if i start it up and press the gas pedal, it revs up and down really quick like there is no air going into it.
So thats y i assume they must be right about the upper-intake-gasket but is that right u think?


And also if I start up the car and let it sit there for about 10-20 minutes later the engine overheats. First thing I did was buy a thermostat but that did not resolve it, I dont want to buy everysingle part so if anyone has a clue i would appreciate it if u can help. Otherwise i will buy a new radiator cap to the best i can think of.

My5ABaby

iTrader: (7)

Whoa whoa whoa. You overheated it?

I really doubt an upper intake gasket would have that much effect especially since it's just old, not left off or something. It might be old and causing a vacuum leak, but not that big of one.

What happens when you put it in gear? If you're driving and you hit the gas and absolutely nothing happens except reving up and down, sounds like you're in neutral.

Anyways... here's some info on fixing idles.

Looping idle
99% of the time "looping idle" , or jumping idle is caused by the following:
Vacuum leaks. This is number 1! These cars are very old and prone to developing leaks. Check and check again for leaks. Check Intake manifold, intake piping, and the EGR
The other cause is the TPS sensor. Be sure to set the TPS when the car is at full operating temperature.

Bad idle speed
If you idle speed is incorrect IE too low or too high, you should try to adjust it. Here’s how:
1. Warm the car up, check your TPS sensor adjustment.
2. Jumper the initial set connector (green socket on drivers side fender near ignition coil with 2 connectors)
3. Start car up.
4a. If the idle is smooth with jumper in. pat yourself on the back. That’s an easy fix.
4b. If it does NOT smooth out, proceed to check for vacuum leaks.
5. While the initial set jumper is in, set your timing to spec. Adjust your idle speed to 700-800 rpm.
6. Adjust your variable resistor (mixture settings) until the engine is idling as smooth as it can. Re-adjust idle speed back to 750-800 rpm.
7. Now is a good time to check your timing. Check and adjust your timing, then repeat the above steps to get idle speed back to 750-800 rpm.
8. Remove initial set jumper. You're done.

Do all this first to verify your idle setting are correct.

If after you pull the initial set jumper the car begins to have a surging idle again, the culprit is probably a clogged/bad BAC. Remove your BAC, clean it well with carb cleaner. Reinstall the BAC and try again.

Idle speed wont hold after adjusting idle speed
Try resetting the idle again, but set it with engine on full load. adjust the BAC and idle mixture with all your lights on and the AC on, it helped a lot with mine.
If I tried to set mine with no load it would do a fine 750 idle with the initial set jumper in, but when i pulled it, it would creep back up to 1200-1300 rpm with no load.

Idle rough at load/ with AC on
Same as above. Set idle with engine at full load with initial set coupler in. You might need to adjust your idle mixture by using the solenoid resistor which is on the passenger side right by the pressure sensor. You will have to remove the factory plastic covering the screw before you can adjust it.

Car will not idle under 1500 rpm
Vacuum leak vacuum leak vacuum leak. You have a vacuum leak. Check EVERYTHING. Start with the Intake manifold joints, intake piping, and the EGR which is prone to leaking.
One of those pages (from teamfc3s.org) mentions putting a 10k resistor in the BAC plug, and with the ignition ON but not started check the voltage across that resistor to see what the ECU is outputting. They say less than 5V is a Bad Thing.

GoldenRexasaurus[fc]

Thanks for the help My5ABaby.
-Yes it overheated and it seems to be doing so everytime i start it up after a while.
-When i put it in gear it does nothing as I press on the pedal it jus revs up and down and i can hear/feel the engine shaking like air leakage.
-If I start up the car the rpm is at 3000 for a few seconds (but its a normal startup to warm the car right?) and then it normally idles at 1000 to 1500 so that is a problem i will try to fix.

BUT WHATS WIERD is that jus now when i started up the car, i can press on the gas pedal and drive it, BUT every other time when i start the car up it wont do anything but rev up and down with engine shaking.

-oh and should i forget about the upper-intake-gasket?

GoldenRexasaurus[fc]

ACTUALLY, when I try to drive it, 1st and reverse gear works fine, but when I try to shift to 2nd gear it wont go any faster and the car shakes until i put it in neutral

My5ABaby

iTrader: (7)

Yeah, you probably fucked over your coolant seal. Do a test and see if you did.

I wouldn't say that exactly, but it wouldn't be the first thing I check.