halfshaft5

Well here it is, recently got another yes 3rd FD so trying to resurrect it. It has a newer engine in it but the pilot bearing froze up on the previous owner and he got disgusted and sold it to me pretty cheap. I fixed the clutch problem so thats over. Now the car sat for 18 months without being driven, started every once in a while but never driven and I have done a complete revamping of all the suspension, rubbers, etc... Now the mods I have bolted onto the engine, please understand The mid pipe I installed is there for mockup purposed only so disregaurd the lack of other mods to accompany it. I am trying to find a cheap enough cat to put back in its place, the original was rusted bad so I trashed it. Anyway here it what it has:

HKS Down Pipe
HKS Mid Pipe
HKS Cat Back
Motor with fewer than 1k on it
New plugs
New wires
Will have new air and fuel filter tonight
and new vacuum hoses all over that are visible with all the manifolds on anyway

I have done the TPS fix but little better but not a lot.

ANyway heres my problem, this thing is running RICH and I mean Rich. It starts flawlessly and ideals awesome for the first 20 seconds then starts stumbling then it gets a slight ideal backfire you can hear in the exhaust. Driving it falls on its face shifting from 1st to 2nd and as long as I keep the power up over 4k then it shifts fine but man it lacks the power. over my other two. It will backfire on deceleration some and if you try to feather the trottle it will flood and die. I can start it back by only holding the accellerator to the floor and crank it and it will start in about 5 seconds. I cant am not running it hard but it just is lacking power my others have and I have a R1 with 109K on the orginal motor. Seems like the turbos are not spooling like they should and the air pump is still there. I have check most of th erest of the vacuum routing againt my other cars so it seems correct. I have run some fuel system cleaner (Gumout) I think and has not seemed to help. I know its going to take some investigating but not wanting to run up a huge bill at a garage. I have worked on cars for sometime now but these things just get me puzzled. I am thinking I will but new plugs in AGAIN and filter and see what happens but it just is getting aggervating so who knows. If anyone can lead me to new searchs or lead me to some links I am will ing to try whatever I need to do to do it right. I plan on building a track car out of it but I want to make sure I can get it back to stock as soon as possible. Another thing is that the previous owner drove the car with the pilot bearing locked up in it for a few weeks before he parted it so he flooded it several times I am sure. What do you think. Thanks in advance and god bless.
Michael

Deals Gap Rotary Rally

iTrader: (6)

18 months.. Try to drain the old fuel and try with some new premium fuel.

Double check your vac job and also all the one way valves.

Have you done a compression test? I don't think thats a problem.. but might be a good idea.

Check all your connectors, also your crank angle sensor and such. Make sure the connectors are well clipped and wires aren't loose.

If you are running stock ECU, make sure the O2 sensor is plugged in.

Good luck! I don't think its anything major from what you have stated.. Probably something simple!

halfshaft5

Oh yeah the compression is good on both rotors. Not sure where the crank angle sensor is but will look for it. I will keep trying, thanks and god bless.

Where aroung Deals gap are you?

weetbix13

reset the ECU... check the plugs AND wires from the coil harness to the battery harness.
i've just had a very similar issue - turned out to be one of these plugs.

mine would start fine and idle right, then if the engine flexed under throttle it would pull a wire loose in the plugs i'm mentioning... then drive like **** for the rest of the day.

halfshaft5

I will check them in a minute, good idea but seems to happen even if its just sitting there and idleing so probably not, never hurt sot look though, thanks for the response.

weetbix13

believe me, mine happened at all sorts of strange times.
have a look at my thread about it - maybe some common symptoms?

https://www.rx7club.com/showthread.p...ht=boost+issue

halfshaft5

Well it makes sense but I will just have to see. Do I need to pull the UIM or can they be reached by just pulling the elbow?

weetbix13

plugs and wires... just have a look in and see if you can get to 'em... otherwise pull the elbow.

halfshaft5

Well tried it and still the same. MAybe it has something to do with the Air tempo sensor or something along those lines. I ahve the air fuel mixture screw on bottom of the trottle body completly closed and it still idles at 11-1200 RPM. Might be a vacuum leak by chance? Lwt me know of more suggestions. god bless

halfshaft5

Update, checked the plugs and wires and alls well, pulled the UIM and all vac. lines are good and even replaced the ATS with a new one I had laying around from another project. Put everthing back on and here is the result.
The idle is high around 1200-1300. A little stumbly and choppy but the backfiring is terrible. While idling its shotting flames out hte exhaust about every 10 seconds or so. I have driven it about 50 total miles on 1/2 tank of fuel so its getting way to much. I can not figure this out. What regulates the fuel to this motor, all by the way it will fall on its face at 3k rpm under load but granny driving it will go higher. Will not boost hardly at all so no clue here. I did turn the car on and check codes with the UIM off and soon relized it was a bad idea with all the sensors unplugged so that might be part of my problem so I will reset the codes tomorrow. Any ideas on the excessive fuel delivery, sure don't want to have to fork out any more money than i have too for a presumilbly easy fix so what to check next. Thought it might be a boosting issue all aloong but who knows. I need to get the idle back to normal and then go from there so what next. thanks in advance, god bless.

halfshaft5

still searching for answers!!!!!

CantGoStraight

Said a hundred times but it sounds like the map sensor is unplugged and the ECU is in limp mode. I never saw mention of the boost pressures you were getting to when it was falling on it's face. When my map sensor was unplugged I could get it to go over 3k but only by easing into the gas, it back fired like crazy and idled like it was posessed. If you haven't gotten all the old gas out and filled it with fresh premium there could also be moisture in the tank and you may need to add some water remover to the tank. I wouldn't try boosting too heavily untill you get your gas tank cleared out of all the old stuff (running a couple tanks of gas through it) and possibly moisture, then I'd replace the filter.

dgeesaman

iTrader: (7)

Well it sounds like you've been pretty thorough, but keep going with those things. I would troubleshoot ignition, sensor, and ECU stuff. You can remove the temp sensors and use a multimeter to test them in boiling water. Definitely inspect the wiring harness, or bend over, apply lube, and replace it with a new one.

I would look hard at the injectors. If nothing has been done for them, it's very possible they're sticking open or dripping or something similar. Gumout won't help a bit. I'd send them out for a good ultrasonic cleaning and R&R. I've had good luck with WitchHunter and RC Engineering.

Dave

halfshaft5

Is there anyway to test the map sensor and if its bad shouldn't it though a code to the ECU?

Bad_Karma7

Look in the shop manual, there is a test for it.

halfshaft5

Well I do not have a shop manual, is there one online anywhere? By the way where is the MAP Sensor?

CantGoStraight

Believe it or not there's one (94 shop manual) stikkied at the very top of the 3rd. gen section. The map sensor is right next to thepower booster on the fire wall (drivers side) just above the elbow....I believe it says map sensor on it.

halfshaft5

cool!!!!! I will check tonight. God bless. and thanks

halfshaft5

Update, Map sensor was bad and keeping it from boosting over 4 lbs. Now the issue is stummbling idle and some hessitation when acceleration and horrible amount of backfiring. Shots a 3 ft flame out the exhaust tip and is running way too rich, any more ideas. So far I have made progress but still not there yet?

halfshaft5

I guess I need to pull the injectors and have them cleaned. Seems to me they are dumping fuel the entire time its running. Does this sound possible or am I still way off and its still a sensor problem... By the way should I take the computer off my R1 and try it on this car to see if its still a injector porblem and not a compter problem.