Hello, i just bought my 87 turbo 2 fc a few weeks ago, it has racing beat rev t2 exhaust and was running fine for a while, but recently sometimes after the car warms up, if i rev it up to about 4000rpms, it will start to cut off (like i took my foot off the peddle and then just kept slamming it to the floor). sometimes it backfires when it does this. help please.

 

Your secondaries are not coming on because of poor grounds. Search for "3800 RPM hesitation"

 

yup..... read the FAQ's

 

https://www.rx7club.com/showthread.p...55#post5131155

 

yeah you have some bad ground wires..do what i did just make your own custom ground kit its cheaper than replacing all of them

 

http://i17.photobucket.com/albums/b8...a/100_0433.jpg


i'm pretty sure this is my bad ground wire that i have. But i tried following it to the source, it goes to the back of the engiveand how would i go about changing this wire out?

 

yeah that looks like the culprit, basically all you need to do is unbolt it and swap it with another one

 

grounds/ wires/ Tps/ clog cats/ clog fuel filter

 

alright, i think i'm just dumb, but i found the one ground in that pic and changed the wire and it didn't fix my hesitation. What did that ground go to? i looked under the air filter area for the ground for the pressure sensor. i'm assuming that since i have an aftermarket boost guage and a hks bov my sensor is rigged differently. And i can not find the other main ground locations.

and what is tps?

 

here are pics of my pressure sensor

http://i17.photobucket.com/albums/b8...a/100_0437.jpg
http://i17.photobucket.com/albums/b8...a/100_0435.jpg
http://i17.photobucket.com/albums/b8...a/100_0434.jpg

 

Throttle Position Sensor

Most acronyms are found on the Sticky Page.
https://www.rx7club.com/showthread.p...&highlight=tps

 

the SPECIFIC ground to look for is the ground for the ECU, under the UIM (upper intake manifold) bolted to the block. If it's not that, I highly doubt the TPS would cause the hesitation. Check your secondary injectors, make sure the connections are tight, they are seated right, and that the babies are clean.

 

just trace/replace all the grounds one by one

 

Hey whats that black box coming off the pressure sensor called?

 

no idea, i think it has something to do with my aftermarket boost guage i have installed near the dash

 

i was trying a few things and test drove it to see if it stopped, and found out, if i ease the gas up, it can go up to 4500 then stop, and if i floor it, it can go as low as 3500, is this usual for the infamous hesitation? could this still be an electrical problem?

 

Probably. Have you tried revving it neutral? The secondaries only come on under load. See if you can rev high in neutral. If you can't, then you may have some other problem.

 

i tried revving in neutral soon after the car warmed up and it was fine, then i tried to rev it after driving it for maybe 10-15 mins and it did the same thing....could this be a bad fuel pump or fuel filter?

 

did you fix that ground? i guess i could say some stuff about grounds but a very wise man already has it writen...http://www.aaroncake.net/RX-7/grounding.htm .. as for the fuel pump maybe take the hose off that goes to the rats nest from the fuel filter the feed line. and measure the output it should five you at leat 1.3 liter per min or .34 gal per min. i usually just fill see how much it buts out in 10 seconds and do the math, it would be better to do the entire min though... all of this info is easily accesable @ your local frequently asked questions section scope it out theres alot to learn

 

Bump. anyone know what that black box is, or does, on the boost sensor?

 

fuel cut defencer (FCD)

 

Nice so I guess my FC does have a FCD.