uRizen

iTrader: (2)

Dammit, I've always idled smoothly at 500rpm, and did some cleaning up and cut a hole in the top of the filter box for more air esterday, and after I cleaned up and took her for a drive, everything was good.. no, great.

This morning I took her out for a bit, and suddenly it started to drop below 500rpm and sputter. I got her home, checked the TPS, cleaned the connectors and the plunger, then removed the BAC valve and cleaned that ***** out. I also went about the engine bay and cleaned up all the connectors I could get my hands on, and checked for vac. leaks (none found).

Started it up, drove about for 5 minutes, and it idled smoothly at 750rpm the whole time, and cleaning the connectors must've helped alot, because she acted alot smoother in general. Well, it didn't end well. Just as I'm getting ready to pull in the driveway, it started to do the same damn thing again.

I did a compression check yesterday and came up with 110 front, 100 rear, so the engine isn't dying, and I also replaced the spark plugs today and checked the wires for any problems, and they are nice and clean.

I don't know what could be left. Grounding seems to be ok, I don't have any hesitation issues, and I cleaned what grounds I could get a hold of.

One thing that kinda bugged me was when I was adjusting the TPS screw thingy, I could not get it to go to 1.0ohm without running out of screw backing it off. I had the positive lead on green, the negative on the orange, and the reading was moving with the screw. I couldn't get any reading using positive in green, and negative on a body ground like the guide I was reading said to do.

Well, any suggestions are most welcome. It'll be interesting to see how it runs tomarrow morning.

Russ

dirty injectors?

WAYNE88N/A

Check out your TPS from the ECU, meter on voltage, car running...That way you're checking the whole system out, and voltage readings are inherently more stable than the resistance checks...Should have 1 volt (plus or minus .1v) at pin 2G to ground (middle plug, 4th upper pin from the right), with the engine warm (linkage off of the fast idle cam). Adjust accordingly with her running, till you get the 1 volt....You're set...Now, turn the engine off, put key back on (don't start), leave the meter on, and push the throttle slowly with the peddle until the TPS maxes out, at around 3.7 volts. No meter needle jumps while the voltage is climbing means your TPS potentiometer function is good (no "dead" spots)...Simple...

uRizen

iTrader: (2)

Hmmm, I'll have to give that a try tomarrow morning. Where is the ECU located in am 87 FC? I'd like to go through and reground everything if time permits. Do you guys know of a good guide I should follow on that?

I don't think it's dirty injectors either. I know one or more is leaking, because if you let it sit for more then 3 days without running, you get a nice smoke cloud for a minute or so. There is absolutly no hesitation during acceleration though, so I think they're ok.

Do you think the fuel filters could've been suddenly clogged? From the looks of them they don't seem to be too old. They're relativly clean compared to the area around them.

syklone

ECU is under the passenger floor boards. You have to remove the capeting, and then a metal plate to get to it, but it is there, next to the firewall.

uRizen

iTrader: (2)

Ok, took 'er out today, and it held 750rpm for ~ 5 minutes, but then started doing the "I'm going to die at this stoplight" dance. I stopped at UPS, went out again, and she held at 500rpm for the next 15 minutes of stop and go, and after I got gas, held strong once again. Maybe I scared those bastard bugs out, how knows?

I'm still going to adjust the TPS and re-ground everything next week for good measure.

poor_red_neck

Check the fuel pump sock and fuel filter?

Just an idea.. the fuel pump sock is probably dirty anyways. I took mine out and had all kinds of **** stuck to it. Sut and the like.

uRizen

iTrader: (2)

Hmmm, that's an interesting idea. How do you get to that SOB? Further note: It started doing it again on the way home from work. So what could cause it to be ok on the way there, then go to **** again 8 hours later? I'm thinking it has to be electrical.

Oh yeah, and it's really loud when I mosh the gas now. I blew the engine side main cat gasket again, and I think the one on the ohter side of the cat is gone too. I don't think those will do much except annoy the neighbors.

Touya

I am having simular problems with my FC. It will idle ok for a bit then it will idle all wild between 1k and 100. Sometimes it stalls out in a turn into some gas station when i'm giving it no gas. I know about |-| that much about the Rotary and could use some helping hands to show me how to do some general maintence on the car. IE: this TPS thing that I know isn't from Office Space, the fuel pumps, and grounds. I got the car as a project car so I am in this to learn about the engine and the fun of fixing it up. Anyone in the Detroit/lansing/Ann Arbor area that could lend a hand?

Also, if you solve the problem let me know what it was, might help my situation.

Hollywood56

Check the fuel pump,fuel pump sock, and your fuel filter.

Touya

I'm not all to sure where the Fuel Pump, Sock, and Filter are on the 13b. I went from working on my 03 Focus to this Car so i'm not to familiur with the engine. Would love to g2g with some other metro detorit people that could show me some of the ropes.

Tiers

I think it is dirty injectors, and you say "I don't think it's dirty injectors either. I know one or more is leaking, because if you let it sit for more then 3 days without running, you get a nice smoke cloud for a minute or so. There is absolutly no hesitation during acceleration though, so I think they're ok."

but that is a contradiction.

Anyhow, I just had my injectors cleaned and my god what a difference! Idle is flawless now (had both bouncy idle and hot start flood problem).

I am absolutely positive that a very good percentage of the problems listed in our forum are caused by old dirty filthy injectors. The crap that was clogging my injectors was mind boggling that my car ran so dam good beforehand. Injectors are the most overlooked piece of the puzzle in a FI car surprisingly. Most people assume they are ok cause the car runs, but you just have to have em cleaned or replaced to see what you are missing.
Also the stuff you add to the gas tank cannot do a good cleaning whatsoever, it can help "keep" them clean but do little to clean them once they are clogged etc.
Remove them and get a proper job done (also a quick tip if you replace them yourself, dont forget to put some oil on the o rings when reassembling keeps em from pinching and makes a good seal on install. ALSO there is a plastic diffuser right below the injectors in the block that should be removed and cleaned when you take the injectors out of the engine. It pulls out pretty easily, I used a bent strong wire to pull em out. They were as gummed up as the injectors themselves.)

Hope this helps someone out

uRizen

iTrader: (2)

I suppose I should just suck it up and send them into Cruzin' while I still have my Accord laying around. I'll have to remove that whole intake chunk to get them out though. As far as discharging the fuel system goes, does running it and pulling the plug on the pump work, or will that screw with a rotary? Oh yeah, any good tips on removing them that the Haynes might not warn me about?

Thanks bros! I'm going to ground everything starting Monday as well, so we'll see how that effects performance.

Tiers

Top end removal is simple, if you are unsure of any hose or wire just label them it only takes an extra minute for security. Be VERY careful not to drop a nut or debris down the intake, jam rag in the openings ASAP. Take your time but dont worry things go back together easy. THe FSM has a good intake removal instruction page btw.

To "discharge" fuel system, just unhook plug at fuel pump in cargo bay, connector is on the drivers shock tower under the lining, and run engine till stall. Use a rag around fuel lines when you pull em off and you can catch the little remaining fuel under slight pressure. Dont forget to pull those defusers under the injectors in the block I mentioned cause I bet they are gummed up too. New gasket is not always required on Intake runners unless it ripss up on removal just put gasket seal on old gasket top if it looks good.

Regardless if this solves "EVERYTHING' I can assure you that your engine will run 100% better when you get everything figured out after doing the injectors.

Terry

tong53

i had a simialr problem. had idle problems. did not run right. i found that if i moved my engine wiring harness i could control how well or how badly it ran. so i replaced it and have been problem free since. just an idea go out and play with it while it is running. if moving it around effects how your car runs then its prob either a lose connection somewhere or like in my case a bad wire in the harness.

uRizen

iTrader: (2)

Sweet, the problem has been taken care of and she idles perfectly at 500rpm again. I did what WAYNE88N/A suggested, and it worked swell, and while I was down there I ran 4 new grounds to the ECU, which smoothed things out considerably. The lights no longer dim when I come to stop signs.

Hopefully I'll be able to ship my injectors out if I can find the time to yank them off and all that, but it might be awhile. For now she's running great. Thanks for all the helpful advice guys!

Tiers

Good news! So many little things effect how our cars run eh, but I wouldnt trade the fun I have had playing with my Rex for nuthin. I have owned soooo many cars (41 years old now) in my life and have NEVER had the "I want to work on my car" feeling like my RX7's give me. Even back in the muscle car days when I owned 68 Cougars and Mustangs, it always seemed more like work then rewarding fun. Dam them Japanese!

Terry

Touya

Glad to hear yougot your idle problem under controle. I also managed to fix mine for the most part. I think it was a mixture of a vac problem in my cai that was a really bad install from the previous owner and dirty injectors. I still want to clean the injectors by hand but I did run some Prestone Fuel Injector cleaner through the system, I also only have used 93 octane since i bought the car 4 weeks ago. Played with the TPS and got her to idle at around 750. I couldn take her lower but this is acceptible to me. Still looking to clean out more and get under that hood, and I agree, there is just something about working on my RX that gives me a warm feeling that I never got when I was building up my focus.
Just knowing that I personaly without having to take it to a shop fixed a somewhat serious problem that was plauging my car makes me feel so good, my baby runs a lot better now, purrs at 750 roars at 8000.

-matt

uRizen

iTrader: (2)

Yeah, I have no idea what causes that feeling, lol. I hunt the how-tos and forums just looking for something to do on my time off. I'm prepping to build custom skirts and flares over the winter months when the garage is just too damn cold.

I used to spend 3 hours a day on my computer doing carious things and playing games, but now it's all car, hehe.