toxindm

Okay hey guys I have a 1989 rx7 gxl it had an automatic to manual swap long ago before I bought, I have had some problems with this car though, sometimes when I go to places the car turns off just as an example, say I am going 40 and I hit a big bump and then the car will turn off, I can turn it on with the clutch or with the keys, but it does it every so often. Not sure if it's the fuel pump or because the tank is dirty. It will jerk/hesitate sometimes too while I am at a constant speed as well only sometimes but my main concern is why it turns off. Thanks if any help

Aaron Cake

iTrader: (1)

Battery cables loose?

satch

iTrader: (1)

You could also have a loose connection at the engine fuse box, Main Relay or the cable which powers the Ignition Switch. You can unplug the four wire plug at the Main Relay and jumper the B/G wire to the B/Y wire as well as jumpering the W/Blue wire to the Black/White wire. Doing so will bypass the relay and narrow down your possible causes.

toxindm

Thanks guys ill update. So far have checked all groundings and right now cleaning the gas tank since that may be the problem as it is very dirty. The car does buck sometimes even at regular speed could be a gas problem right?

satch

iTrader: (1)

Bucks at a steady speed, decelerating, accelerating?

toxindm

Yeah ^ does it pretty randomly.

toxindm

Okay now that I'm on a computer I'll be able to reply good. No the battery cables are not loose at all as I did check all the grounding spots and took off the battery and put it back on. Now today I checked and cleaned the tank. So far it hasn't done it all today we will see by tomorrow if that fixed it. Btw I do have the check engine light and I know what codes I had gotten. It was code 1, 9, and 13 I will recheck if 13 is gone as I did change the pressure sensor. Code 1 is the trailing coil I am not sure if that could be causing the problem. And 9 is only the sensor from the radiator for the water which had broken off from being old.

satch

iTrader: (1)

You want to make sure the Water Thermosensor is working and connected properly as it provides feedback to the engine what the coolant temp is and this helps the ECU to decide how much fuel is used at start up and during driving conditions. The car does not really require the trailing coil to work to run the car but if it is working intermittently that could affect the overall drivability aspect. And the Pressure Sensor being problematic would also cause driving issues as the response would be somewhat jerky.

Aaron Cake

iTrader: (1)

Start by checking all the grounds:
Proper RX-7 Grounding Procedures

toxindm

Yeah the thermosensor is just connected to a ground so the car can shut up because of the noise in the inside. So I should probably get one soon I've looked through MazdaTrix and it's pretty cheap. And I think the trailing coil is marked as a code because the rpms are not connected correctly. This car was auto before and the previous owner switched it to Manual. The car hasn't turned off anymore so far today for the 13 miles I've driven it but it does do the Jerk mildly. I will have to recheck if the pressure sensor I bought as I got it from the Junkyard about a month ago. And Aaron, that is how I started by checking all the grounds and cleaning them and reconnecting them.

satch

iTrader: (1)

The Water Thermosensor is found at the back of the water pump. The sensor on top of the radiator is a coolant level sensor and not a thermosensor. You have these two sensors confused.

cab91089

iTrader: (3)

There is one ground wire from the battery to the main fuse box on the drivers side strut tower. About a foot before the main fuse box on that wire there is a ground on the strut tower. The 10mm bolt that holds it in place sticks into the wheel well and gets really badly eroded and rusty. That one ground will cause the hesitation you are experiencing. Clean the ground and replace the bolt. Its hard to see if you still have A/C and P/S.

toxindm

Can you post a pic of what the water thermosensor looks like and yeah guess I had the names confused. Thanks though. And Cab I will check that out as well then Thanks for that. And yes the car has power steering and Ac. So maybe that's why I didn't see that wire I will give it a check asap and Update.

satch

iTrader: (1)

I don't have a pic (Mazdatrix site has a pic), but at the top of the water pump and behind it lies the Thermosensor which should have a Green plug that looks exactly like an injector plug and it has two wires to it though they should be shielded. The alternator is poised right above it ( at least it is on an S4).

cab91089

iTrader: (3)

On the s5 there are 2 plugs into the waterpump but the thermosensor is still a green plug.