snakebite662000

so my 88 rx-7 will cold start, then idle for about a min, then die.

my throttle position senser is out, and we thought that it was flooding, and it seems as if its not getting gas.

changed plugs, wires.

so this it the other thing. when it finally starts. say after 30 min of trying to start it. it runs fine.

HAILERS2

What happens when the engine is FULLY warmed up, and then you turn it off and try to start it up after a few minutes? Idle ok? Die after a minute? Or?

Just looking for clues. Speaking of clues, have you read the trouble codes yet? Most won't effect the start/idle of the car other than a fault for TPS or Water thermosensor or AFM.

http://web.archive.org/web/200805250...odes/main.html

snakebite662000

everything is just fine. starts back up. no codes. no CEL. nothing.

HAILERS2

Since it starts up and idle fine after fully warming up, I'd put my money on the water thermosensors plug being off the sensor or one of the contacts inside the electrical plug that goes to said sensor is pushed back not making contact.

Water thermosensor is on the back of the water pump HOUSING and is colored green and has a two wire electrical plug attached to it. If you look and think its connected.........don't stop there. PUll the elect plug off and look inside the elect plug to see if one of the contacts in the electrical plug on the harness is pushed back.

And or you might check the codes using the site I attached earlier.

The ECU defaults to a 176*F reading for the water themo sensor if the plug is off the sensor, that is why the car would start and idle fine once hot...........but not cold.

Then it could be another thing. Won't know til you check it out.

snakebite662000

ok i see what you are talking about. ill try to make the DCC sytem lights. LOL

I will let you know my results

matt87FC

iTrader: (12)

Id like to add some advice to.this as i used to have a pretty similar issue. Only after sitting all night in the cold would i have an issue. Check out your secondary injector connections. (i heard they aid in cold starting? I could be wrong) One of my secondary injector connectors was actually bent somehow on the inside of the connector and not connecting. I bent it back how its supposed to be and havent had a cold start issue ever since (about 3 weeks now).

NatAsRex7

iTrader: (5)

my car did exactly the same thing. it would take me almost 15 minutes to start. when it did start it would die while i drive it or after it idles for a while. after doing non stop deflooding procedures it was just a bad battery. my water thermo sensor was also bad so i changed that.

ty97206

So what snakebites car is doing is the following:

If you start it up it will run for about 2 mins then dies, you can get it started back up if you play with gas pedal while cranking it.

We have replaced or trial and error the following:

TPS (seemed to help a little with the new one in place)
bypassed the fuel filer-changed nothing
new fuel pump-changed nothing
check for crank shaft senor-changed nothing
mass air flow sensor-changed nothing
computer-changed nothing

When you take the car to about 4,000 rpms the rpms drop about 1,000 and pops in the exhaust.

We are going to try the O2 sensor still but we are kinda at a loss here. We have done a compression test and its good on compression.

Any advice here would be really appreciated

snakebite662000

Thanks Ty97206

the work is appreciated.

what r ur plans this weekend??

drifter_xs

change ecu and see if it works lolz ... happened to me

HAILERS2

Sounds just like the secondary injectors are disconnected from the harness. Might be just one disconnected.

Go to the ECU and backprobe the secondary injector wires in the ECU plug and with key on/engine off, they should read batt voltage. IF they do.........then I'm wrong about them being disconnected. IF they don't........then pull the intake and put the plugs back on the secondary injectors.

Sure as heck ain't no 02 sensor problem whatsoever.

How stuff works..........primary injectors are the only ones working til you reach 3800 rpm and put a LOAD on the engine. Then the duty cycle of the primary injectors drops in HALF and the secondary injectors come online to make up for the loss of primary duty cycle. IF the secondarys don't come on.........then the primarys still cut their duty cycle in half and the car falls on it's ***. Lack of fuel. EVen one secondary failing can give the same result.

Fried secondary injector drivers could cause the problem also. That's ECU related failure.

Cars that have a very hard time starting COLD but start fairly well when warmed up ................is almost always caused by a water thermosensor being disconnected. Common problem on this forum. Put the plug back on it after making sure the contacts inside the elect plug are not pushed back not making contact with the sensor. Or simply backprobing the water thermosensors wire at the ECU plug would tell if the circuit is being made or not. Hot engines show approx a half volt when backprobing the input to the ECU.. Cold engine would show b/t 2.3 vdc. Disconnected sensor would show 4.5 to 5 vdc.

LunchboxCritter

iTrader: (9)

If you end up pulling your UIM to check your secondaries, I would suggest that you check the ground wire on the top of the engine. If it looks to be in good condition then simply remove it and clean it really well before reattaching it.

snakebite662000

do you have a diagram so i could see what pins i need to backprobe. and how do i backprobe? pull the plug and testit???

satch

iTrader: (1)

Click on 88FSM. Wait for the download icon to appear. Then download the FSM. Then click on "Fuel and Emissions NA" section from the list and the info you need is in this section.

http://foxed.ca/foxed/index.php?page...nual#secondgen

snakebite662000

OK good news. there is a little sensor on the back of my intake manifold (S4) its the air thermo sensor. that was shot. now its back to running. it flooded this morning so im gonna add a kill switch!