RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   2nd Generation Specific (1986-1992) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/)
-   -   Confused!!! (intermitent hesitation?) ...wayne.... :) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/confused-intermitent-hesitation-wayne-343299/)

hondahater 08-29-04 09:51 PM

Confused!!! (intermitent hesitation?) ...wayne.... :)
 
What would cause this? Here is what happened, I connected my pressure sensor up and I started getting the hesitation again then I disconnected it and caped the vac line and no hesitation at first then after about 10 to 20 minutes of driving it started coming back but only sometimes other times I would boost to 13-15psi and there was no problem. I'm getting so close to finishing but damn it the end keeps eluding me or maybe I'm just eluding myself into thinking there is an end :)

ilike2eatricers 08-29-04 09:55 PM

Do you have the restrictor pill in the pressure sensor line? I still dont think that it would make it hesitate that badly though. I'm guessing it's the TPS.

WAYNE88N/A 08-29-04 09:58 PM

Did a PO put that damn extra ground wire on the boost sensor? Follow the wiring down from the plug & make sure nothing is spliced in...

Very well could be a bad TPS, as ricers stated, although they don't go bad very often. Are you sure it's a turbo boost sensor, not an NA?

hondahater 08-29-04 10:02 PM

um don't know if its n/a or tII I'm going to buy a good pressure sensor from another forum member just to see if thats it. Also the tps is one I just got from another forum member and seemed to check out fine. I set it and everything. Anyways I'm not to sure what you mean by PO??? But I put an extra ground on there :) I guess I could take it off if you think that will do something. could I just take the ground off of the chassis and tape the end and try it that way before unsoldering the connection??? no I don't have the restrictor pill. I don't know if it is needed or not? Man I'm just full of questions aren't I lol!

ilike2eatricers 08-29-04 10:06 PM

PO=previous owner

hondahater 08-29-04 10:10 PM

AHHH!!! makes sense :) thanks man!

WAYNE88N/A 08-29-04 10:15 PM

Without the "pill", you're going to get erratic voltage spike inputs to the ECU, but heck, I do that with my NA (boost sensor code comes on everytime I romp in any gear, even with the pill in) because of the exhaust (I'm guessing)...I've run without the pill before, back when I was near stock, and it didn't seem to do anything funky, so???

Yeh, take that boost sensor ground off, just remove the bolt for now, and keep the terminal from hitting ground (tape it up if you want). You got so many dang problems, that could be one of many, lol...

Is your rear rotor housing ground in good shape? And your tranny-to-firewall ground wire?

hondahater 08-29-04 10:32 PM

yeah both are in good shape and I will take the extra ground off as well as get another pressure sensor, and thanks for reminding me that I have a bunch of problems :P :) Anyways I gotta try this tomorrow because my neighbors are sleeping and my 7 is kinda loud! I'm also going to lower my idle tomorrow via the idle possisioning screw, wish me luck, lol.

WAYNE88N/A 08-29-04 10:40 PM

Wish you luck??? I just wish you were sane :)

hondahater 08-29-04 10:44 PM

man one day you need to come down here and fix all my problems, beer and food would be provided :)

Rx7MPGUY84 08-29-04 11:07 PM

dude its on the way to my house in fl. hell yeah. its a conquest. wayne goes state to state for free getting food and beer for fixing mine and hondahaters 7. Sorry your having problems again. i thought u were working out good. guess ur back in the boat with me. good luck hondahater.

hondahater 08-29-04 11:08 PM

lol thanks man. It's not anywhere near as bad as it was but it is still there sometimes. Good luck to you to :)

DerangedHermit 08-29-04 11:10 PM

Let's not forget a side trip to Tennessee :).

WAYNE88N/A 08-30-04 12:57 AM

Lol, you guys are killing me...A traveling rx-7 repairman, that's a good one. I do plan on "semi-retiring" at 45, but you're gonna have to wait another 6 years for that one, unless a particular airline goes kaput first :)

87RX7TII 08-30-04 08:11 PM

are these the same boost hesitations?

DerangedHermit 08-30-04 08:40 PM


Originally Posted by WAYNE88N/A
Lol, you guys are killing me...A traveling rx-7 repairman, that's a good one. I do plan on "semi-retiring" at 45, but you're gonna have to wait another 6 years for that one, unless a particular airline goes kaput first :)

Which airline? *evil grin*

hondahater 08-30-04 09:22 PM


Originally Posted by 87RX7TII
are these the same boost hesitations?

yes they are! I still need to set the idle correctly and hopefully that will help I'm also going to get a good pressure sensor and maybe even an afm. Hopefully this does something :)

WAYNE88N/A 08-30-04 09:47 PM

If you want to throw parts at it, be my guest, but this is why I wrote the "troubleshooting from the ECU" thingy for you guys. AFM and boost sensor inputs can be easily read from the ECU while doggin' her.

Hermit- impress me...which airline has a major hub in Houston?

hondahater 08-30-04 10:22 PM

I just find it hard to trouble shoot the computer while driving and some how right when it bogs for that split second you have to look down at your multi meter and somehow catch the problem in a split second. Maybe I'm just doing it wrong how would you suggest doing this???

WAYNE88N/A 08-30-04 10:36 PM

This is kind of deja'vu- I was checking my AFM on the way to work today, because I've got this weird "not quite a hesitation" going on when the car hits a shallow "bump" in the road and goes "nose down". It's a split-second thing, like a primary is not firing just once, then everything's normal again...You gotta have the meter in the seat next to you, at the very least, and this is possible using the "alligator clip" jumper wires and a small piece of wire inserted into the ECU pin I refered to in the ECU writeup. But you're right, it's tough to look at it exactly when the "problem" is happening, especially if it's an intermittent thing...

Anyhow, the AFM looked good, nice and steady reading the whole way, so I'm gonna do TPS tomorrow, then something else every day until I nail it. But that's the beauty of the process- I'm not wasting money and throwing parts at it...

Yours sounds much worse than mine, though, so should be easier to nail down. Just be patient and hit all the sensors you can at different times. Heck, if you have to, read one out & verify it's working, then pull off to the side of the road and put the wire/probe into another sensor's input, then take off again...If you have a copy of the FSM section that has all the pin locations & voltages, it should be a piece of cake. Remember to write everything down, so you can compare things later if need be...

hondahater 08-30-04 10:50 PM

sounds good I'll have to get aligator clips for my pos multi meter and a long enough wires for ground and power. See what I'm thinking is that when it bogs if it is something else telling the injectors not to come on intime wouldn't it tell you the injectors aren't firing however couldn't it be something causing the injectors not to fire like afm, pressure sensor??? What I'm saying is if I try the secondary injector location on the ecu first and sure enough it's the injectors not firing what do I do from there? couldn't it be a bad something else causing this problem???

WAYNE88N/A 08-30-04 10:56 PM

Lol, slow down...Even if you figure out the injector stops firing for 1/4 sec or whatever (the voltage on the meter will actually go UP for that), you still have to figure out WHY it's not firing, which means making sure the sensor inputs that have to do with fuel scheduling are all good...AFM, TPS, CAS, boost sensor, water thermo sensor, the intake air temp sensors, the atmospheric pressure sensor, you get the idea...Make sure all these bad boys are doing what they're supposed to be doing first, then jump to the injectors if you want...

hondahater 08-30-04 11:00 PM

ok sounds good thanks! I've got one more question, the air temp sensor I would emagine is the prong on the stock inlet duct under the tmic. Does it matter which way you put that sensor on??? or as long as its plugged in its fine??? When I pulled it off the first time I didn't check to see if green was on top or black was on top. Thanks.

WAYNE88N/A 08-31-04 12:37 AM

I don't exactly know where yours is, mine's on the left side of the dynamic chamber...

In any case, it's just a simple thermister, shouldn't be polarity sensitive, so it shouldn't matter which pin gets the power side, as long as it's dropping the voltage as it should for a good input signal to the ECU...Which you can read at the ECU, lol :)

Bad2ndgen 08-31-04 01:31 AM

This may sound way off but you should just check. Check you resistance across your plug wires. The first time I ran into this problem, I could not figure it out for days. I checked every sensor, every pin at the ecu ect. with no results. Sence I figured that out I have had 5 or 6 more cars with the same problem, all of them would hessitate right as you got into boost. Anyway its worth a shot.

Oh and just for your refrence, for testing sensors and ecu outputs ect. I would advise using an oscillascope (spelling?). Most of them have a logging feature so that you dont have to look at them while driving, you just record the voltage or sign waves and look at them later. I think you can rent them at most auto parts stores.


All times are GMT -5. The time now is 07:21 AM.


© 2024 MH Sub I, LLC dba Internet Brands