RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   Car is slow.... WTF? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/car-slow-wtf-176995/)

Terrh 04-16-03 12:47 AM

Car is slow.... WTF?
 
I gutted the cat today.. it looked decent, there was some minor cloggage but nothing major and no melting. got a bit more boost, about 1/2 way up the gauge regularly now. About 1/10th of the time (seems to do it far more often if the exhaust is cold... e.g. after light driving or just after starting it after it's cooled for a bit) I can get to nearly the top of the gauge, and can hear the turbo spool up... pfffffFFFFFFFFF...

The car is slow, tops out at ~105MPH... accelleration seems decent in the lower gears, but nothing that ~200HP should be like... Feels a quicker when the turbo spools right, but nothing stellar...

WTF is wrong here? anyone have any ideas?

No idea if these are connected but:
there is some general idle funkiness... sometimes it'll idle rock solid at 800RPM... most of the time at 1500.. sometimes pulsing between 1500 and 1800... any ideas here either?

my gas mileage seems to be horrible, I have about 130 miles on this tank of gas and I'm down to just under 1/4 of a tank....

Cosmo Donk 04-16-03 09:53 AM

Dunno. Check timing, your TPS (might be bad), injectors because that is pathetic milage. Are they stock injectors?

Strong spark?

Terrh 04-16-03 10:12 AM

TPS was recently set (2 oir 3 days ago)
the car doesn't flood, which leads me away from injectors... Timing was correctly set 2 or 3 days ago too.
New plugs and wires last weekend.

Cosmo Donk 04-16-03 10:23 AM

Well, 130 is downright miserable. How are your vacuum lines? Does the wastegate move easily? I think if you grab it with a ppliers or something you should be able to move it. Maybe it is sticking open?

YakATK 04-16-03 12:09 PM

Compression test. My NA was doing the same thing, felt real shitty for acceleration and was just terrible for top end power. It had characteristics of an engine that was NOT blown though, but compression test yielded extremely low compression on rear rotor. So get that checked just to rule it out.

CompuBob 04-16-03 06:54 PM

I allready checked both the wastegate and the compression.

compression is fantastic, wastegate moves easily.

-- Terrh

Bambam7 04-17-03 12:15 AM

Do you know what sort of PSI you're boosting at?
What about your twin scroll... is it functional????
Check the intake system too.... what sort of intake setup do you have??
Sounds like you have some nice vacuum leaks too.

Do you have a front cat or a DP??

It is definatly not running up to par. Topping out at 105 is sick.

What RPM does boost start to kick in at?? Maybe a leak in the IC piping.... that you cause your bad idling....

Terrh 04-17-03 11:06 AM

twin scroll... I dunno. Next warm day (tomorrow, maybe? ) it's getting wired open.

Cat and precat are gutted. Precat pretty much gutted itself... cat was a PITA and looked to be decent, though.. oh well

intake is stock, and I'm sure I have a vacuum leak somewhere..
in first or second I see full boost (well, as full as I get.. about 1/2 way up the stock gauge) pretty late - 4000RPM?

erp... come look at it :)

Roy James 04-17-03 11:11 AM

Yeah man, i say if your compression is good and turbo is fine then you have a vac leak or leak in your turbo intake lines somewhere (they are prone to cracking as are the vacume lines). Id go ahead and replace all the vac lines and see if you have a leak in your intake piping somewhere. Use a can of carb cleaner or starter fluid to see if you can find a leak, spray it and if the idle bogs or goes up you have a leak. Good luck.

Bambam7 04-17-03 12:06 PM

4K is waaaay to late to get boost... That eliminates the twin scroll pretty much.....
Maybe your intake is very restricted for some reason, or your turbo is pooched.
If you have a leak in your IC piping or other big boost leak big enough to loose that much power, than your car would most likely be running like total ass, and you would also HEAR the boost leak- the're LOUD!!!!!
I would be a little worried about your turbo unless you know 100% that it's good.

I'll look at it tomorrow!

Amur_ 04-17-03 01:04 PM

Terrh - get in on the silicone vac hose buy and use it for new lines. Two birds, one stone, nuff said (unless you've already got silicone in there...) :)

Terrh 04-17-03 01:07 PM

a fair amount of new vacuum lines, but none are silicone... $15 for 20ft of regular vacuum line :)

maybe if it came in black... :)

Amur_ 04-17-03 01:21 PM

That's what Tremclad is for. ;)

Terrh 04-17-03 01:29 PM

lol... thanks anyways :)


All times are GMT -5. The time now is 11:24 AM.


© 2024 MH Sub I, LLC dba Internet Brands