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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...
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.
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.)
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.
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.
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.
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.
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?
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
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.
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
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)
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.
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..
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.
07-02-15, 10:09 AM
