MattsFc3s

Hey everyone having a problem with not getting any fuel on the lower spark plugs, i have spark,cranks on start. But no fuel coming to the engine anyone know why?

also i refreshed the fuel and the fuel systems changing the filter,pump,lines, etc all but the original fuel fuel filter in the engine bay. anytips/ insight would be greatly appreciated thanks

*everything else is working except for fuel to the engine i.e no pops or bangs when cranking, just straight cranks.

diabolical1

iTrader: (3)

welcome to the board.

what does this mean? it is sort of unclear. are you saying you changed the filter/sock in the tank, but not the filter behind the driver's front wheel?

you can get a copy of the FSM from here: Foxed.ca

what you need to do is test the pump and move forward to see where the blockage is. is there something keeping the AFM door from opening and therefore the pump does not come on? what about the pump relay? if the pump comes on when it should, find out if the fuel is getting to the rails. if the fuel makes it to the rails, then find out if the injectors are bad or getting power. that sort of thing.

also, when was the last time that car actually ran?

Cardinell

A couple things to check here.

Check the AFM and the associated wiring. The S4's (unsure about S5) only run the pump once it gets a signal from the AFM.


On the wiring harness that runs next to the LIM, there's a 2 position yellow connector. Jumper that with the ignition on, and see if you can hear the pump run

MattsFc3s

thank you both for your insight i found out my ground wire on the battery positive wasnt connected and i needed to be for my fuel pump relay.... lol

anyways finally got her to fire up on that note yes i forget to replace to fuel filter in the engine bay but it seems fine.

also when i start up it jumps to 4k right off the hop im assuming this is normal for a cold 13b? also it dies unless i tap the throttle.

MattsFc3s

sorry for not giving the best details either i know that can be a pain if u have anything you think i should mention let me know

Cardinell

The revving to 4k is part of the factory cold start system. It's intended to light off the cats. That's normal. When you say it dies, you mean when the idle comes back down?

MattsFc3s

yeah when it starts up around 3500-4k the rpms go down quickly and it dies right out. this motor hasnt been started in a few years, ive also made mutiple attempts to see if it would warm itself up but no difference. i set the tps to 1v aswell and set the idle screw on the top (counterclockwise)

MattsFc3s

it revs out like it has good compression and when i bought it from a local he gave me the numbers and they were fairly even around 110-120 psi

MattsFc3s

also its a 1987 s4 NA gxl

Cardinell

TPS should be set with the car fully warmed up to operating temp. The cold start system is mechanical and props the throttle blades open until the car is warm. This throws off TPS readings.

I would adjust the idle per the FSM. That can be found here

MattsFc3s

do you think my bac valve could be a cause of why no idle?

Jeff76

In short, I do beleive the answer is yes. Short search here. The long answer is it could be many things. The BAC came up enough here with I do beleive was idle issues, that member hailers??? seemed a little hot under the collar to be helping another person with similar problems. It seemed that most were the BAC. I could be remembering wrong though, so take that with grain of salt.
A few things I do know:
Member Cardinell was asking about the TPS, do it while fully warmed. sit in the car with your foot on the gas if you have to till full working temp.
These things need done in a certain order if I am not mistaken and the member gave you task #1 on your path.

If these are done out of order, such as not warming the car before adjusting the TPS, it will send you down a rabbit hole you don't want to be in.

Not advise here but in my car I somewhat solved the very same idle issue by taking it on the back roads and I opened up the throttle/RPMs to blow out some carbon build up. It never completely solved it but was way better. Mine still dies and has a very low idle. One of my solenoids is reading weird so I will start there eventually after the TPS set again.

As a side note some don't recommend the TPS and ohm meter, they recommend using the two light method. I would have tried already but I misplaced my LEDs after checking for codes.

If it suits you better please ignore this post all together. I am pretty easy going. I will be watching as I need a solution too. Thanks!

MattsFc3s

fair enough thanks for the insight none the lesss i try and give the warm up idea a try with holding the rpms and i let you know.

MattsFc3s

tried a few times got the engine pretty warm, still didnt hold any idle also its hard to keep on the gas unless im above 3k other wise rpm's dropped instanly and dies right out

any suggestions?

i see alot say massive air leak but where would be the most usual spots you would look in this case?

Jeff76

You never reported if you warmed the car to normal temp.This could cause issues because you turned it while cold. 3k is nothing for these cars, it will be ok. Also watch the temp gauge closely, if it rises quickly and find the root cause. If the massive air leak is of very great concern, then find those first.

The FSM is not very detailed on "stalls after high idle" or similar with a quick search I found:
1.
(I seem to not be able to post mutiple links???)
Not sure if the Gen 3 info is usefull or not.

By massive air leak, you mean vacuum leak? Most of the tips I know for that are with the car running. Searh "vacuum leak 87 RX7" or similar. If you have trouble findining them with the car off, search some more for general info in the interwebs.

I think you get the idea. I am to busy to post often, I will come back oveer the weekend. Checking all the vacuum lines will be very time consuming anyway. Best of luck!!

MattsFc3s

turns out i forgot to plug up something on the lower intake manifold once i did that i was able to get her to idle!! super happy thanks for all the advice everyone now i just gatta figure out why my coolant temp sensor isn't coming on and dail the idle. It's currently sitting around 1.3k-1.5k

Jeff76

Good work finding the leak. I apoligize for being a bit harsh. I was having a hard time fiquring out what you wrote. Double apolgies if english is a second language.

If this car has been sitting, flushing out and possibly running a cleaning solution in the cooling sysyem, isn't a bad idea. Also, the reading of the sensor seemed out in mine and I checked one at a parts store and it was nearly identical. You might have to get good with reading schematics. There is at least one wire, grounds at the engine I think, that go from the ECU to the sensor. Then from the ? to the guage cluster. Back probe at the ECU from the sensor at pin 2I and a good ground. Your readings at the sensor should be very close to the same. If not, ohm out the wire from the ECU to the sensor and replace or repair if needed. Also regrounding the ECU ground wires that connect to one bigger wire further down the wire loom is recommended. Adding additional grounds and redoing current ones are recommended to, there are tutorials for this. I think I found them on the 3800rpm hesitation writeups. If you can, put a bit of dielectric grease on the connections, especially spots where you removed paint, including any wire inside any lugs you may have to crimp, just don't overdue it. And if you splice with lugs, use heatshrink tubing.

The pinout #'s and test voltages start at 4A-30 in the FSM. The end has the map, so to speak, of the pins as seen from the rear of the connector at the ECU. I am not sure about the schematic, I haven't looked into it to deeply yet as I like to read those on paper.

MattsFc3s

thanks so much for the advice i really appreciate it, shes currently running and drive very smoothly idle a safe 750rpm (stock 6 port motor) only having issues with a short in the meter fuse/cluster to deal with now and i can finally get her ready for the road! after a 2 year waiting feels good to hear the rotors spin though (p.s sorry for late reply didnt get notifications)
@Jeff76