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-   -   hesitation when i step on gas (searched) (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/hesitation-when-i-step-gas-searched-900101/)

florotory 05-14-10 06:41 PM

Ok so I did the compression test and it was really low. So I want to make sure that I did it correctly.

Step by step:
1 started and warmed up to norm op temp
2.pulled top spark plug on rear rotor.
3.hooked up compression tester
4.pulled fuel fuse
5.turned key on and cranked
6. read 68ish psi

did I do it correctly

RXnos1200 05-14-10 07:02 PM

I usually pull out the egi fuse...
Then I take out the bottom plugs and open up the throttle body all the way. Battery should be fully charged......
remove valve from comp tester.....
then I crank the engine over and take the test. DON'T forget to remove the valve from the compression tester first.
you want even bounces during the testing.......

florotory 05-14-10 07:16 PM

Ok what valve are you talking about on the tester?

RXnos1200 05-14-10 07:36 PM

the shrader valve on the comp tester.........like the tire air valve......

florotory 05-14-10 07:40 PM

OK it would be in the end that gets threaded into the sparkplug hole correct? I think I know what your talking about.

Also I was reading on Rotoryressurection.com that you have to pull both bottom plugs at the same time is that correct? Thanks for all the help. I really really hope i did the compression test wrong

florotory 05-15-10 08:50 PM

ok redid compression test. both rotors were close to 90psi. the rear rotor was a lil lower but my battery sucks and started to die. from what I can tell it has good spark like I said my battery died while trying to test.

I guess my next thing to do is to take the UIM back off and make sure I have everything hooked up correctly, I am going to test the coils with a meter. I just gota look up in the FSM what the specs should be, is there anything else I am missing?

RXnos1200 05-15-10 09:06 PM

you ever check fuel pressure? Stock fpr probably can't handle the walbro pump....I wouldn't rely on it.....

florotory 05-15-10 09:25 PM


Originally Posted by RXnos1200 (Post 9998886)
you ever check fuel pressure? Stock fpr probably can't handle the walbro pump....I wouldn't rely on it.....

not yet i bought the tester just havent had time to test yet. So where should I put the tester? Before or after the regulator? Thanks for all the help, I cant wait to figure this out so i can drive my car

ecko 05-15-10 10:45 PM

if your plugs are smelling like gas your deff dumping way too much fuel and your timing can be way off.

datz 05-16-10 12:03 AM

youve already put a little money down so just get new plugs, try them, if thats your concern.

florotory 05-18-10 09:06 AM

ok I decided to take the UIM off again to double check all my vaccum lines. Where does the FPR vaccum line connect. I looked at the FSM but the Diagram is not very good. Anyone tell me which one of the Hard Lines the FPR connects to.

sharingan 19 05-18-10 09:23 AM

It connects to a nipple on the middle of the LIM, it points at an angle towards the firewall.

Fuel pressure? the system should be about 38psi (did mine last night) the max pump pressure should be about 90psi (stock anyway, wouldn't surprise me if
that walbro is pushing more fuel through those injectors than the ecu is expecting. My car was otherwise stock when I got it, but it had a 255lph pump. It would always flood, and every time I started it, I'd get a nice puff of black smoke.

florotory 05-18-10 09:37 AM

just to be sure ill take a pic and post it. Cause looking at the FSM (like i said it sucks for diagrams) it shows it going to one of the hard vaccum pipes near the EGR. IDK if it makes much difference but it is an s4 TII. Ill post pics

florotory 05-18-10 09:46 AM

http://i89.photobucket.com/albums/k2...c/212_0981.jpg

ok the hard metal line that is to the right of the Oil injectors. Is that the FPR line?So a vaccum hose would go from the nipple tat angles toward the firewar to the metal hard line. Then the metal hardline would connect to another vaccum hose to the FPR? is that correct. If so can I just ypass the Hard line go straight from the angled nipple to the FPR?

florotory 05-18-10 10:40 PM

ok well after taking the tps off and testing it i realized that i was testing the ohms with it on the car instead of volts. Im going to put it back on the car tomarrow and hopefully that was my problem. I dont think it is but at least it will be one less possibility

Feargone 05-19-10 01:27 AM

Check the intake system, had this problem a while back.

jinxed4dub 05-19-10 02:07 AM

1 Attachment(s)
Your vacuum spider is broken for the oil injectors that would be a vacuum leak, The hose closest to fpr is the right one, and it looks like a open vac port near the oil injectors. I'm not sure I don't have the rats nest anymore, so I forgot all about all those parts.

florotory 05-19-10 07:04 AM


Originally Posted by jinxed4dub (Post 10005113)
Your vacuum spider is broken for the oil injectors that would be a vacuum leak, The hose closest to fpr is the right one, and it looks like a open vac port near the oil injectors. I'm not sure I don't have the rats nest anymore, so I forgot all about all those parts.

Ya I bought a vaccum spider from a member from here. I broke the old one while trying to get the old vac hoses off. I still have the rats nest (for now). I found the FPR line it was one straignt down below the FPR and it goes to one of the silonoids with the orange plug that is by the oil filler neck.

once I get this thing running smoothly again I will be deleting emmisions completely. but im gona wait for a while cause I have had the car in my possesion since October and havent really been able to enjoy it, thats why I cant wait to get it running. Plus my 6yr old is coming down from wyoming to visit and hes all about cars so Id like to have it running before he gets here

florotory 05-19-10 09:50 AM

ok I just made a code checker (thanks to fc3spro). I didnt get any codes. So at least that eliminates about 10 sensors that are still good. I do have an extra set of plugs i think im going to swap them out for the news i had in. see if that makes a difference

florotory 05-19-10 10:07 AM

Ok i started the car and ran it with the code checker in. The light didnt come on. So i revved it up a couple times and about 10 sec later it flashed code 10 i believe. (long flash,pause long flash,pause,long flash pause ect,) so that would be my o2 sensor. would that cause my problems? thanks

florotory 05-19-10 07:16 PM

ok i was messing with the leading coil and it would spark when it got near metal. the rpms would go up and then settle again. could my coil have a bad ground causing it to malfuntion? could that be causing all the issues? Thanks again guys

MazdaMike02 05-19-10 09:47 PM

Dude your all over the place, stick to the basics.. Compression, Fuel, Spark

Now I would also include exhaust. The Catalytic convertor, can plug and cause hesitation. Put your hand over the tailpipe and verify you have back pressure. 1.5-2.5 psi is normal, anything above and theres probably a restriction. You can't measure unless you have the proper gauge in which case you can't really use it on a 7 because theres no pre and post cat o2 sensors only the one on your exhaust manifold.

Either way, hit the cat with your hand, if it rattles its probably plugged. If you get nothing its fine and its time to focus elsewhere.

I would also chase intermittent shorts, like in the fuel injector wiring circuit.

jinxed4dub 05-20-10 01:28 AM

your igniter could have eaten shit. change your plug wires, and see if that fixes it. the code checker really isn't much of a help. removing your emitions now will simplify alot of things. and it will also fix alot of problems. knock on wood since I removed it I haven't had to pull the egi fuse once to deflood. and before I had to pull it once or twice a day. any time I hot started some days. its been running strong for over a month now. where as before I had a new problem every week. I still have a few issues, but for the most part have a good running T2 now. but I see kids pugging there noise any time they walk near my car when its running. I don't even smell it. but then I was use to my FB

florotory 05-20-10 07:00 AM


Originally Posted by jinxed4dub (Post 10007134)
your igniter could have eaten shit. change your plug wires, and see if that fixes it. the code checker really isn't much of a help. removing your emitions now will simplify alot of things. and it will also fix alot of problems. knock on wood since I removed it I haven't had to pull the egi fuse once to deflood. and before I had to pull it once or twice a day. any time I hot started some days. its been running strong for over a month now. where as before I had a new problem every week. I still have a few issues, but for the most part have a good running T2 now. but I see kids pugging there noise any time they walk near my car when its running. I don't even smell it. but then I was use to my FB

The spark is coming from the metal bracket that the coils is attached to. would that still be the wires or the unit itself not grounded good or cracked ( didnt see any cracks but will check again)? I do know that the idle raises up a bit when it does arc from the coil bracket to something metal on the car. thanks again for all the help. I hope this is my issue so i can finally drive this damn thing again

jinxed4dub 05-20-10 08:20 AM


Originally Posted by florotory (Post 10007350)
The spark is coming from the metal bracket that the coils is attached to. would that still be the wires or the unit itself not grounded good or cracked ( didnt see any cracks but will check again)? I do know that the idle raises up a bit when it does arc from the coil bracket to something metal on the car. thanks again for all the help. I hope this is my issue so i can finally drive this damn thing again


If the sparks are big your igniter is junk, or it could just not be grounded as you said. take it off clean it up reinstall. takes all of 3 minutes to take off and put back on. you may wan't to take the back off and look at the igniter while its out. I'm shure theres a method to check the conditon of the connections with a dmm in the fsm.


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