2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

utter loss as to whats wrong.

Thread Tools
 
Search this Thread
 
Old Jul 2, 2015 | 09:58 AM
  #26  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
yeah it will be rough to get them out. easiest method is to dremel a slot in the head to use a flat head screwdriver. next best method is welding to the head of the screw but that is extremely dangerous given where this needs to be done...
Reply
Old Jul 2, 2015 | 10:09 AM
  #27  
RXSpeed16's Avatar
Theoretical Tinkerer
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (41)
 
Joined: Oct 2003
Posts: 1,600
Likes: 49
From: Norcal/Bay Area, CA
Originally Posted by Jzavala
Welp, stripped five of the screw heads now on the fuel pump door.

As I expected, Wisconsin rusted them seized. I'm going to stop while I'm behind and have a shop pull the thing as they're Phillips button head screws and there's no way of getting them out without drilling them out really.

All on the same corner too so they'd have to be replaced or I wouldn't have a good seal.
Use vice grips (needle nose if you have them) to grab the head of the screw. Once you break it loose, they should turn by hand.
Reply
Old Jul 2, 2015 | 10:10 AM
  #28  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
I got it out. Fuel sock looks OK. I'm guessing its the pump after all then? There is some crud on the bottom of the tank but its not so bad to make me worry really. Minor debris, nothing the filters can't easily handle.(clean as hell for being 27 years old I think.)
Reply
Old Jul 2, 2015 | 10:16 AM
  #29  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
looks fine to me, but if you wanna throw money at it...

pumps usually have two modes:

working normally
dead as a doornail
Reply
Old Jul 2, 2015 | 10:36 AM
  #30  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
Well I recall reading the stock fuel system isn't good for much more power than I'm making as well. 200whp on entirely stock fuel system as far as I know, previous owner could have upgraded injectorsors, 10:1 a/f ratio at redline when I had it synod.

i think i failed to mention this as well. it takes 2-3 times to get the car started as well. if i shut the car off right after it was running, it starts right up without an issue, hot or cold.

Last edited by Jzavala; Jul 2, 2015 at 11:24 AM.
Reply
Old Jul 2, 2015 | 11:37 AM
  #31  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
getting close yeah, the stock turbo pump is good for about 230-240whp. if you want to upgrade anyways then sure may as well rule out the possibility.
Reply
Old Jul 2, 2015 | 11:46 AM
  #32  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
Originally Posted by Lyger
looks fine to me, but if you wanna throw money at it...

pumps usually have two modes:

working normally
dead as a doornail
i used to believe this as well, but have since found it to be a common misconception. a pump can become weak before going kaputz. however, many times the symptoms aren't extremely prevailant to cause concern enough to check..until it does calf. maybe some intermittent misfiring under high load situations. it does happen. more often than people think.
plus i figure he's planning on throwing in the walbro anyways, so it's really all overlap.
Reply
Old Jul 2, 2015 | 12:02 PM
  #33  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
well factor in the unknown(and what looks to be untouched, the car only has 87.4k miles on it so its possible, it still had the OE 1987 shocks and struts when i changed them not long ago) age of the fuel pump and how much power i'm making, and then add on top of that the fact i ran it pretty low once, and then it was run low again to make these symptoms even worse.

adding to it that it runs pig rich anything above transition and rich below it, which would be odd with a sticking injector or even malfunctioning injectors.(the secondaries dont come on until higher rpms even with boost dont they?)

wish i had an ammeter to measure the draw of the pump to get an idea if its working extra hard or not.
Reply
Old Jul 2, 2015 | 12:11 PM
  #34  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
and yes, of course a wb is not going to aid as well as a 5 gas analyzer. a 5 gas is the greatest diag tool a person can have. but they cost thousands. a wb reads 1 gas and costs 150$. but it reads one of the two most important gasses of emissions. it's far from futile. right now he's only speculating.

Last edited by welfare; Jul 2, 2015 at 12:15 PM.
Reply
Old Jul 2, 2015 | 12:18 PM
  #35  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
i thought you said it was leaning out under boost
Reply
Old Jul 2, 2015 | 12:19 PM
  #36  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
how is the idle anyways?
Reply
Old Jul 2, 2015 | 12:41 PM
  #37  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
iat is a major input. high resistance means the ecm is seeing cold, and would dump fuel. but it wouldn't explain running lean in boost. maybe the map. how did you test it?
Reply
Old Jul 2, 2015 | 12:43 PM
  #38  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
but you see what we're doing? still all under speculation. this is not a structured diag without actual data to back up the symptom(s). i mean, you may find the culprit. randomly checking inputs and actuators, but the method is not efficient
Reply
Old Jul 2, 2015 | 12:57 PM
  #39  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
yes it feels like it leans out in boost. the idle is very rough, and uneven/lumpy. it feels like it runs on one rotor at vac even with a load, upon hitting transition with load it runs perfectly, like it should, and under boost it feels like its running on both rotors, but it bogs like detonation.

i may have been off on the resistance, i was looking at the wrong damn page. my own fault, though it did display the resistance for the IAT sensor.(half tempted to pull it out and return it right now. 30k ohm is pretty much spot on.

Last edited by Jzavala; Jul 2, 2015 at 01:05 PM.
Reply
Old Jul 2, 2015 | 01:05 PM
  #40  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
have you checked base timing? i know this happened out of the blue, so to speak, but it is a fundamental
Reply
Old Jul 2, 2015 | 02:11 PM
  #41  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
looking at those plugs (which is the next best thing, if not better than a wb), they don't scream rich or lean. that trailing 1 plug does look black as hell though. maybe that leading plug isn't adequately burning fuel. testing in open atmosphere will not suffice. get your hands on an HEI tester. follow the instructions on using it and test your ignition system. they are dirt cheap, easy to use, and should be readily available at your local auto parts store. they replicate the resistance to the ignition system to what it would be inside the housing/cylinder. which is very, very, different from just open atmosphere
Reply
Old Jul 2, 2015 | 02:13 PM
  #42  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
to give you an idea, the gap that spark needs to jump, under cylinder pressure, is comparable to about 3" in open atmosphere. huge difference
Reply
Old Jul 3, 2015 | 06:04 PM
  #43  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
Right, so before I replaced all the fuel pump access panel screws I went for a drive. Before even that I had the hood open. Lo and behold the fuel pump resistor relay just started clicking widely for no reason, car wasn't even on.

Pretty sure relays aren't supposed to do that.

BUT, going by what i've read online, the MAP also controls this relay, now if the map sensor is bad, it could be sending a false signal to the ecu which actuates the relay.

i thought i checked the map sensor well enough, it did give near proper resistance values for atmospheric and vac pressure the book calls for.(it was very very slightly under)

Last edited by Jzavala; Jul 3, 2015 at 07:52 PM.
Reply
Old Jul 4, 2015 | 10:23 AM
  #44  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
was the key on? typically, when a relay clicks rapidly, it usually means it has an inadequate ground.
Reply
Old Jul 4, 2015 | 11:01 AM
  #45  
lastphaseofthis's Avatar
My job is to blow **** up
Tenured Member 20 Years
iTrader: (8)
 
Joined: Jan 2005
Posts: 2,903
Likes: 5
From: palmyra Indiana
he was already told its his ******* injectors i swapped ecu pins on mine in 5 mins but he wanted to **** with a fuel pump,.

Last edited by lastphaseofthis; Jul 4, 2015 at 03:41 PM.
Reply
Old Jul 4, 2015 | 11:33 AM
  #46  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
Key was on.

I'll check the grounds. I haven't cleaned those yet.

I'll check the injectors as well. Woke up late today so that's out of the question for today. Probably tomorrow.
Reply
Old Jul 18, 2015 | 11:28 AM
  #47  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
Well I did everything I said I would, nothing fixed it.

Re grounded the ecu as well. Nothing.

So its either wiring to the injectors or injectors themselves.

So I'm just going to replace the entire fuel system. I may even re-wire the car for a megasquirt system instead as well to just do away with all the ancient wiring problems. I already have the harness and all I need to do is tear it all down(and since I'll have the intake off, no biggie there as that's about the hardest part of it all just looking at the engine bay) and wire it all back up.

Last edited by Jzavala; Jul 18, 2015 at 11:30 AM.
Reply
Old Jul 19, 2015 | 10:58 AM
  #48  
lastphaseofthis's Avatar
My job is to blow **** up
Tenured Member 20 Years
iTrader: (8)
 
Joined: Jan 2005
Posts: 2,903
Likes: 5
From: palmyra Indiana
Originally Posted by Jzavala
Well I did everything I said I would, nothing fixed it.

Re grounded the ecu as well. Nothing.

So its either wiring to the injectors or injectors themselves.

So I'm just going to replace the entire fuel system. I may even re-wire the car for a megasquirt system instead as well to just do away with all the ancient wiring problems. I already have the harness and all I need to do is tear it all down(and since I'll have the intake off, no biggie there as that's about the hardest part of it all just looking at the engine bay) and wire it all back up.
you could swap the injectors and the car would be drive able until 3800 rpm. swap the 2nds for the primaries..
Reply
Old Sep 20, 2015 | 06:41 PM
  #49  
Jzavala's Avatar
Thread Starter
4 color car, thats me.
Tenured Member: 20 Years
 
Joined: Jan 2006
Posts: 307
Likes: 0
From: Oak Creek, WI
well i solved what was wrong with the car.

it wasnt injectors(though two were leaking lightly, they were all +500cc, cleaned they're all now 549-551cc range)

it was a combination of things on top of injectors being old/dirty.

crank angle sensor was bad(leading 2 wasnt firing much at all, constantly getting fowled up). i ordered a reman from atkins and replaced it .

pulsation dampener was bad, the screw had come out(i've since replaced it with a new one i had sitting in standby).

the variable resistor was bad, it was reading 2.8kohm on one half, and 0 on the other, the thing also spun an unlimited amount. i had one in my spare care, since replaced it and evened it out. but that only really has an effect on idle.

I've since remedied all these issues and the car runs better and stronger than ever.

so even though i tested the crank angle sensor with my multimeter, it was still faulty.

really blew my mind that the car had that many problems, and still ran as strong as it did.
Reply
Old Sep 20, 2015 | 07:24 PM
  #50  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
oops, was stuck on reading page 1

welcome to the FC, problems tend to gang up on you.

Last edited by RotaryEvolution; Sep 20, 2015 at 07:28 PM.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rgordon1979
3rd Generation Specific (1993-2002)
40
Mar 15, 2022 12:04 PM
musker
New Member RX-7 Technical
1
Oct 1, 2015 05:58 PM
Zinraf
2nd Generation Specific (1986-1992)
3
Oct 1, 2015 01:09 PM
ChanBagz
2nd Generation Specific (1986-1992)
6
Sep 17, 2015 03:36 PM




All times are GMT -5. The time now is 04:44 PM.