alright.

i just got my injectors back cleaned by cruzin performance. the reason i sent them out was because the car was bucking under acceleration, meaning it would accelerate then momentarily hit a wall and then accelerate then do it again until i got to either full boost or 4000rpms.

now, i have new injector clips, installed cleaned injectors, added a vacuum hose from the nipple b/w the oil injectors to the second nipple from the top in the row of four facing the firewall on the uim. the top one is for the ebc and the bottom is for the thermowax.

i tried to drive it the other day and the problem is much worse. i accelerated lightly and it wasn't too bad, then i went to give it some boost and right before it accelerated there were 2 backfires and a buck ...so im like wtf this is just my luck. funny thing is, the car idles like a champ at 800 rpms.

please help me out here. this is getting old and i don't want to have to get rid of what seems to be the "typical" rx7 now. my only guess is maybe too much fuel since the problem is worse after the injectors were cleaned.

thanks guys.

 

ECU error codes?


-Ted

 

TPS properly adjusted?

 

TPS was adjusted, no change in drivability
ECU code readout is the 02 Sensor, don't think that is related to the problem

thanks for fast replies already! ...by all means keep them coming because I am out of patience and answers.

 

How about a full travel resistance check of the TPS?

Can you disconnect the TPS and go out for a test drive?
Some cars can do this.
If yours can, try and see if this eliminates or changes your hesitations?


-Ted

 

I don't think it could hurt to run it with the 02 unplugged (unless you desperately need fuel mileage on your test run )

 

Alot of these types of symptoms, (bucking, missing, backfiring, lagging) can be attributed to either a way rich A/F, or timing that is way off. I would check the timing first.

 

Fuel filter?

 

check sparg plugs and wires

 

Again... thanks for the replies guys.

Wires are brand new and plugs were checked out to be clean.

I suppose I can check that, but I replaced it no more than 5k miles ago.

Timing was checked out and is in spec. I DO think it may be running rich, even more so since the injectors were cleaned, replaced, and then car hesitates more and in addition backfires. BUT the spark plugs should determine that and my mechanic said they looked to be good condition. He cleaned them and replaced them as well.

Your suggesting that the TPS may be faulty to the point where, and even though in spec, the car can run like this, potentially?

What does the TPS do? ...measure throttle position and send a signal to the ecu so that the ecu can modulate fuel and timing?

I suspect the fuel pressure regulator could be faulty as well. Anyone know if a datalogged wideband reading can give me any insight to a potential bug in the fuel system?

 

Slightly of topic, but where did you get the injector clips? One of mine flew off in to the nether regions of the engine bay and I cant find it. I know I could look at a junk yard, but I doubt they 7's there would have clips, theyre all pretty stripped.

 

injector seals? Once old and brittle, they will leak like mad.

 

i got the msd-2400 clips from summit $25 shipped i think. pm if you want install help. i mastered it

i got all seals, grommets, and o-rings on the inj replaced already.

 

did you replace ALL fuel filters? (in tank, etc)

 

When you replaced the fuel filter 5k ago...was that when the problem started? I remember awhile back someone installed theirs backwards and had VERY similar problems to yours.

 

Not all no. Just the primary fuel filter in the engine bay. I am replacing it this weekend anyway just to be sure.

Actually, when I changed my fuel filter ...I noticed the old one was on backwards. Needless to say I didn't feel the need to repeat my previous owner's mistake.

My plan this weekend is to test voltage at the pump, replace primary engine bay fuel filter and hook up a fuel pressure gauge. I think with all that diagnosing, one of those would fix it if there is actually a fuel problem, unless bad gas can do that.

 

Change the low pressure fuel filter (in tank), I dont see a need to change the high pressure fuel filter again (the one in the engine bay).

Recheck your TPS. Hook up the multimeter leads and then do a slow full range sweep to check for dead spots or spikes.

Have you checked the pressure sensor? Water thermosensor?

 

maybe your AFM is fubared........i had a buddy whos afm would partially jam up.. his car drove like yours..pooop ..ride the bucking bronco

 

I had a converter that the insides rotted out on and it plugged up and I had the same symptoms as you do

 

i second that mine did the same with clogged cat

 

i think its the cats too mine does the same thing because they are clogged. maybe see if they are red hot after a drive, like mine are.

 

the fuel filter... you say the old one was backwards? how did it drive before you changed it? did it start bucking after you corrected the backwards filter? maybe it wasnt backwards at all

 

I have never had a autozone/pepboys/etc salesman ask if i wanted either the intank one or engine one when I asked them for a fuel filter for my car. Do they carry them or would it have to be a walbro part or something?

I guess I could do a slow sweep check.

Pressure sensor is on my list of things to check as well. Don't know why the water thermosensor could cause a problem, or where it even is.

the afm was swtich out already and it didn't make a difference ...but i will check again.

it drove fine in both directions honestly. the bucking started recently, not 5k miles ago when i changed the filter.

I will check the cats as well guys. thanks everyone, i think i have a pretty solid list of things to check now. don't stop though!! i have 7 days to get her running smooth

 

I haven't commented on this, because none of the suggestions I can think of would cause the backfiring. But, since you're brainstorming, make sure you have good contact at the connectors for the AFM and the solenoid resistor (and coils, etc.).

 

I bought/added a restrictor pill AND swapped out the boost pressure sensor.
result: no change

the in tank fuel filter can't be purchased at a car parts store ...so tomorrow i will have the engine fuel filter replaced with a puralator and hopefully find someone to weld in a straight pipe in place of the catalytic converter