toddmac

i am new to rx7s but already love my rotary. but the problem is that my car will start and run for a while and then hesitate for a couple seconds like it is starving of fuel. this usually only happens when it is cold but sometimes happens when it is warm. ive read it could be the bac, afm, injectors, vaccum lines, alternater, and a whole bunch of other crap. my alternator squeals and ive heard that it could do this. tell me what you guys think, anything will help.

Mark S

iTrader: (1)

Need more info, does it do it when idling, or when you accelerate? How long is the stumble... etc.

silverrotor

iTrader: (1)

You can rule out alot of potentials buy doing a Major Tune up before you start assuming It's the BAC Valve, Injectors etc.

The squeal? Replace the belt, It's worn out.

rico05

What are the EXACT conditions of the hesitaion? What RPM? How much throttle is it at? What gear? Any sounds associated with it? You gotta give us more info than that man!!! I agree, just a worn belt. Autozone for like $8.

GLHS

Could be that loose belt causing the problems.

giving you voltage drops and causing a miss fire.


tighten the belt and give us a update

toddmac

well the stumble usually happens at 2000 to 4000rpm. I replaced the alternator yesterday and it stopped for a day. i guess it could be the belt but it isnt belt squeal, it sounds like the bearing on the old alternator was going out. oh and it usually happens when it is not at full operating temperature. and now its idling at about 1100 rpm except when i stop, where it drops to about 500-700 rpm. it also, when cold, just shuts off. it will start back up instantly when i turn the key but i dont like it doing it. dad says i should junk it but i love my rx7. the rotary kicks a$$

wickedkin6s44

Damn dude,

I would start out with a tune up...and then look at it from there. If it still happens let us know on here and hopefully we can help out.

wickedkin6s44

Angel Guard Racing Team

I would check the water thermo sensor (The square plug on the neck on the water pump)

Amur_

BAC! Get the car running and unplug the BAC. The idle should change. If it doesn't (remains steady) then replace the BAC.

Doubt it. I killed my water thermo sensor last winter and it didn't cause this. The car was nearly impossible to start when cold and ran like **** until it got up to temp. Once she was warm she was 100%.

toddmac

GLHS said could be a misfire, wouldnt i hear a misfire. i just drove it and it doesnt make a sound it just shuts down like the fuel pump or ignition ciols are going out, but then i think (not sure yet) but it only happens when at full operating tempurature. so the water thermo sensor might be it, but what does that sensor do, what is its purpose? because it starts semi ok but then it just runs like crap. the bac probably needs replaced or cleaned cuase it also shuts off when i brake or turn the tunes up loud, or lights on. i dont know, it could be a number of things, what would be the first thing to fix???
hey thanks alot though guys, your all freakin awsome!!!

Amur_

The water thermo sensor checks out your coolant temp when you start the car and the ECU uses this to adjust the start up. If the ECU is trashed and there's no signal (like the way mine was) then the car goes into limp mode during start up.

Limp mode= configured for hot start.

Not good in January in Canada.

If you have a multimeter you can check the BAC for proper resistance. DOn't have the FSM in front of me... But do the unplugging check - my BAC had proper resistance but I didn't know it was bad until I unplugged it (my revs drop a litttle under eletrical load - not like yours but noticeably.)


Btw, there's no quicker way to get on my black list than to ask for help, get a bunch of suggestions, and then post asking for more help like you haven't tried any of what's been suggested... GLHS also said to tighten the belt. Have you? Or have you replaced it, as suggested? Have you unplugged the BAC with the car running?

toddmac

sorry

Tec

Todd,

If you need help working on your car? Your more than welcome to bring it over to or garage! It's right off of link lane, the shop is 5,000sq feet of heated garage with airtools! We even have a pool table and some old school video games

Anyway, I'm leaving for San Antonio today for IDRC Lone Star Nationals this weekend. PM me your # and I'll give you a call on tuesday when i get back.

Brian

Amur_

Make that, "If the water thermo sensor is trashed..."


And that wasn't a grrr reply - shoulda put a smiley at the end.

Go try the suggestions you've been given and then come back with the results. We'll still be here and we'll help you go from there.

toddmac

hey amur the help was greatly apprecitiated. i did replace belts, tested my alternator and bac valve. messed with the water thermo sensor, played with the AFM wires and did kind of a all around look at the engine compartment, making sure everything was connected, and intact. thanks to you and everyone who posted the problen is now fixed. i am still going to replace the bac valve and water thermo sensor. but hey you all kick *** here.

Todd

Amur_