i just picked up a GSL-SE last night for $1000. it has a rebuilt motor with 200 miles on it. just got a paint job not long ago. pretty clean. Anyways the motor starts up like a champ, but the idle is sluggish and the motor rocks back n forth real bad. when i give it gas it tends to hesitate . does anybody know whats wrong with this car. im not use to it cause my first 7 had some R.E. dual weber carbs on it, and i got use to it. now that the GSL-SE is EGI im just lost and don't know where to start. some one please help. thanks

 

vacuum leak , check all hoses.

 

all the vacuum hoses are all new. the timing is right on the dot 5* atdc

 

did you put a vacuum gauge on it?

 

Checking vacuum after the throttles wont tell you if there is a vacuum leak between the AFM and the throttle plates.Almost all EFI rotaries are metered air type EFI,so its critical that there are no air leaks after the flow meter(the silver box near the air filter)

Get a service manual and check the TPS adjustment,idle bypass,and other electronics, and do a regular tuneup.Just because the engine was replaced doesnt mean the last owner remembered to change the fuel filter,or what-not.

The Mazda EFI can be finnicky,but its pretty reliable once you get it all figured out.Probably the most common problem is hot shut-down flooding caused by leaking injectors.Sometimes a professional injector clean/balancing will fix it,other times they just need to be replaced.

 

the car has new fuel filters and new oil. basically it had a tune-up done to it. i got the car from my bro's friend. he builds his own motors and what not. even he can't seem to figure this out. maybe he's just use to his FC's and FD's. i wish someone in san francisco or around the bay can take a look at this thing. everytime i go and try to fix the problem, i just get more n more pissed of. i think sooner or later i might just tear the car into pieces, if i can't get it to run right

 

sell it to me for 5 dollars

 

i swaped out the old injector and put in another pair i got from a friend. the car starts and don't rock back n forth as hard no more. the idle is very bad. its at 400-500, it jumps up n down. i tried to adjust the idle from the air valve thats on the dynamic chamber, but it didn't do nothing. can someone please tell me what you think the problem might be. thanks

 

If you haven't looked at this site it may be helpful:

http://www.nellump.net/peri/epi/firs...gslseIdle.html

Give it a chance and go thru this troubleshooting.

HTH,

Scott

 

Oh and the very BEST way to find any vacuum leaks are to make an adapter to fit the end of the AFM and pressurize the intake system with compressed air. Only 3-5 psi is necessary and you will find every leak.

 

After the vac leak, you'll want to check the plugs. When I bought my GSL-SE the plugs were shot as were the coils and the car exhibited the same symptoms as you.

 

Have you adjusted the TPS yet? I'd start from there.

 

Yeah, a "hunting" idle with a fuel injected car is many times a problem with the TPS (throttle position sensor).

 

From an SE owners/tuners perspective, some things have already been mentioned here that may improve your SE idle quality, but there are others that can be just as likely a source for idle inconsistency.

The 'hunting' idle is usually experienced about this time of year when the weather turns colder, because the throttle rods start sticking in the TB. Simple oiling will usually fix this, best to remove the TB and oil rods (primary and secondary) with one end up, then the other. This ensures that the TB rods turn freely when the secondary throttle valves are choking airflow during a cold start. Does your engine idle get any better after it warms up???

TPS is another often overlooked thing that dramatically impacts, both idle and driveability. Test this with either a 2-light fixture (homemade), or a 2 voltmeter setup. It is a binary system (on/off), so 2-lights work equally well for tuning at idle.

If all else is done, and no improvements - there's one last thing to do to improve idle Quality; the Variable Rheostat. The VR controls the idle mixture which affects both idle speed and idle quality. An overly rich mixture will cause a 'bumbling' idle, where the exhaust pulses seem uneven and the engine may have poor off-idle acceleration. An overly lean mixture is hard on the rotors and bearings and will cause the engine to 'hunt' or move up and down 50-100 rpm. The VR is located at the passenger side strut tower and has a purple connector going to it. The VR may have some paste stuck in the top hole, but grab a small blade screwdriver and remove the paste to reveal the slotted head screw, below. Notice the indications on the VR for L (lean) and R (rich). Adjust in very slight movements on an engine that is already warmed up. Move no more than about 10 degrees at a time, and give the engine about 15-20 seconds to adjust.

This may help you to obtain a nice steady idle condition. HTH, and reply back,

 

i just got thru making the 2 light tester for the tps. on the adjusting tps for dummies page it says to warm up the engine. well get home from school and tried to warm up the car. it starts but don't hold idle. everytime i go n start the car it stays on for like 5-10secs and then dies out. it just keeps dieing out everytime. last night the car was idleing shitty but it stayed on. i don't know whats going on. but i'll figure it out. might take awhile though. i will post again when i get the car to stay on.

 

mite sound goofy but have you checked the fuel pump.

 

adjusted the TPS, got the car to idle at 800RPM for about a min. after that it started to act up again. checked the BAC valve its opening and closing all the way. I'm thinking its one of the VSV. what do you guys think

 

alright guys, this might sound crazy but i think im going to make my own wire harness for the car. this might take awhile but im not tripping. i can't drive the damn thing anyways. can someone please tell me what sensors i need and don't need thats hooked up to the ECU (i.e. all the important sensors, selenoid, etc...) another thing is the TPS. yesterday i adjusted the TPS using the 2 light tester, it was correctly adjusted. when i turn the car off and turn it on again it was out of sync. does this mean the tps is messed up? any help is greatly appreciated. thanks

 

Check the flap inside de air flow meter it must be free and easy to... well, flap. On my GSLSE it was not moving freely and the car was idling and running very poorly, I have that car for the last 10 years and I'm still learning Gimmicks on the car.

 

air flow meter is good. flap opens and close smoothly. today i started up the car and it idled at 1200 rpm for a good 5-10 mins. i tried to turn the idle down by adjusting the Air adjust screw and it didn't help alot. drop the idle to about 1050 rpm. all of a sudden the idle drops to 600rpm and stayed there. Standing on the driver side of the car i notice the green plug was clicking and bleeding off air when the car is getting ready to die out. that got me thinking. i did a search and it said something about that selenoid or valve is for the advance on the distributor or something. when i go and plug up the hole with my finger i can feel it suck in air and bleed out air. if i cover the hole up completely the car dies out. WTF? why won't the car just idle at 800rpm? i switch out the injector, helped out a little motor don't seem to b rocking back n forth as much. took off the TB and cleaned it (very dirty) cleaned the BACV, checked all the vacuum lines everything is okay. what am i doing wrong? i wanna get the car running right so i can feel how a fuel injected 13B runs. HELP ME PLEASE!!!!! I didn't spend a grand for nothing.

 

When I bought my -SE last year it was doing the same thing. I bought a manual for the car and was reading it and for some wierd reason I wanted to check the coil wires going to the distributor. I found that the leading and trailing coil wires were crossed. After that the engine ran smooth. When I drove it down the street before fixing the mixed up wires it also hesitated before accellerating.

 

thanks for the info. i'll check the coil wires as soon as i get home from school.

 

got home from school and spent the whole day messing with the car. at around 7 sumthing pm i got the car to idle smoothly at 800 RPM. when i go and take the car around the block it starts acting up again. while driving down the street, the car runs really poorly from idle to about 3,500 RPM. hesitates, boggs, doesn't pick up smoothly. when i go and open the throttle all the way it seems to run fine. anyways, I get to the end of the block and the car dies out. I had to crank the car for awhile for it to start up again. any ideas on whats going on?