blackedoutFC3S

iTrader: (7)

so i just bought my 89 GXL about a month ago, and i wasnt able to drive it much because the throttle body controller that was about the TPS had broken off so there was no place for a screw. so i bouth a TB from russainmob (grea seller) and put it on my car thinking that was the only real problem, then today i took it into this guy who used to be a mechanic for mazda who gave me a free 29 point inspection, and when he came out all he had was bad news... first of when i drive my car (which im not right now cuz i knew it has problems) when i stop accelerating and try and keep a consistent speed the car starts jolting back and forth and the check engine light comes on, next whenever the car idles, the idle bounces up and down a lil bit which is something i thought just needed tuned but i guess its more then that, and it needed an alignment and new belts, and its also been running really rich which i thought was from the TPS so i was going to replace that tonight. so i took it in knowing this and he came out saying one of my housing was running rich and that theres a chance one of my apex seals is broken or could break because of the jolt, he said but this could also be from a number of things which included leaky injectors, or just bad injectors on one housing, it could be a vaccum line, it could be the header is not on too tight, or possibly it could even be my car is low on coolant (was going to replace liquids tonight) so i need to check all these things.

i just wanted to know if someone has had this problem before or has any idea what it could be? its killing me because i thought my car was just about ready to be road worthy but its not looking that way now. if anyone has any suggestions of what it could be please let me know! im open to any ideas, specially if any of you have had this problem before! thanks a lot to any of you who read this!

matt

NJGreenBudd

iTrader: (1)

It could be any number of things, probably a combination of many different things, you already named a handful like vac leaks, improperly adjusted TPS or throttle body, fuel delivery issues or internal engine damage just to start with.

Sounds like you need a full tune up to start, change those belts and add coolant, change the oil and filter, check timing and TPS once warmed up. You nned to check the basics like fuel air and spark, check your compression.

blackedoutFC3S

iTrader: (7)

ya i literrally just changed the oil two days ago, tomorrow night comes coolant and hopefully those belts, then i think ill move on to the injectors from there... how exactly do i check to see weather the timing or TPS is off? and i think i might go ahead and grab some new spark plugs... alright i guess i better just start working my way through.... thanks alot NJGreenBudd! so far from what ive seen your one of the most helpful guys on the sites pretty sure youve helped me out before ha

NJGreenBudd

iTrader: (1)

Ha....I don't know about being the most helpful, but I'm glad you've benefited from the forum.

You should check the timing with a timing gun, there should be instructions in the downloadable FSM located here-
Index of /main/factory_service_manual/1986_1988

You can check/set the TPS by bypassing the the intercooler with pvc pipe and letting the car warm up, then check it's operation and resistances with a Digital Mulitimeter, specs can be found on here by searching. It's so much easier to adjust with the TMIC removed, the piping allows you to clearly see all of the throttle linkages and TPS while the car is running.

Pvc like this-


Look here for more TPS info - Mazda RX7 TPS Adjustment





But I would advise checking your compression of each rotor housing as a preliminary measure, get a "compression tester" from Advanced Auto or whatever and lets get an idea of the condition of your internals. If your compression checks out then you can move on to finding all of the vacuum leaks and bad grounds that are certainly there. Search for compression check for more info.

And have a nice day.

shadoe

its a gxl so its not a turbo'd app but that's still pretty cool ha

NJGreenBudd

iTrader: (1)

okay, it was late and I didn't catch that, your TPS will be visible since you don't have a TMIC, I believe the specs should be the same though, I have heard that the TPS are swappable between NA and Turbo, I am using an NA tps in my TII right now.

The manual that I linked to was for S4 but if you go to the parent directory you'll find the link for S5, look in the Fuel and Emissions section for NA-

Index of /main/factory_service_manual/1989_1991

04A_Fuel_and_Emission_control_systems_non_turbo.pd f

These are from www.teamfc3s.org.

Hope that helps, but check your compression first.

Roen

iTrader: (2)

If you do adjust the TPS system, you will have to reset the ECU by unplugging the battery's negative terminal while the car is off and leaving it off for at least 5 minutes.

It's the TPS that's at fault, the full sensor usually goes, and when it does, you have loads of bucking. The only way around it is to buy another TPS. You can adjust it to minimize the problem, but the problem is still there. I've posted a method on how to adjust both the narrow and the full on the S5's, you'll have to dig through my old posts to find it. TPS' retail for $360.