AE_Racer

iTrader: (1)

Right after Christmas I took my 1992 JDM FD to a local track. After 3 or 4 sessions it got hard to start. Crank, die. Crank, crank, full throttle then off, finally started, idled and ran fine for another session.

The following week, I had a similar experience where it took a few tries to start and run. I changed the plugs back to some used BUR7's and 9's, which made no difference, but otherwise the car ran and drove great. A few days later, I could not get the car to idle at all. It starts, shoots to 1500rpm and immediately dies.

I decided to order a set of new plugs, at this point thinking its flooded, and try to deflood. I pulled all the plugs, cranked it over multiple times. New plugs installed, same result. I can keep the car running by blipping throttle but it fights me constantly to shut off.

Mods I believe pertain to issue at hand:

• Power FC
• Stock primaries, bosch 2200 secondaries
• Air pump removed

Things I checked:

• No work had recently been performed on the car besides me working on the tune via PFC and datalogit. I've reverted back to the 5.08 base map since the issue just in case it was something I did but same result.
• Each wire for spark, seems strong.
• Map sensor is plugged in, and the vacuum hose to it is connected and in good shape.
• Unplugged ISC, only difference is it goes to 8-900rpm and dies vs 1500.
• No visible vacuum leaks.
• Pulled vacuum line from OEM FPR, not wet.
• Pulled fuel pump as I didn't know what it had, its a stock pump and connections are good.
• Jumped fuel pump via diag port, it runs as asked.
• Cold and corrected compression numbers taken yesterday via rotary compression tester: front rotor all faces ~105, rear rotor all faces ~95. Also note that my jumper box was getting low.
• Fuel filter changed yesterday, same result.
• TPS voltages read a tick high in the PFC but not crazy.

I've run out of ideas. I don't have a way to test the fuel pressure, at least that I know of. I've searched and searched, seems most people with an issue like this is fueling or the map sensor. I ordered a walbro 255 and install kit last night as it wouldn't hurt regardless. Thought i'd post and see if this issue jumps out to anyone while I wait on the pump. If that ends up fixing it, great

Thank you as always to this forum and the vast knowledge available.

TomU

iTrader: (11)

If you have good compression, my guess is TB related. Did you try starting with the gas pedal to the floor?

DaleClark

iTrader: (55)

Have you tried putting in the fuel pump jumper and starting the car? The ECU has different circuits for running the fuel pump when cranking and another once the car starts. Wondering if it's something there.

Dale

AE_Racer

iTrader: (1)

Compression numbers are in the OP. I believe I did and it wouldnt start with pedal down. I couldnt figure out if holding the pedal down would keep the injectors from firing or if that was an FC thing. Ill try again this afternoon.


I believe I did this as well. I definitely jumped it to hear it run and pretty sure I tried starting to see if it made a difference. Ill do it again this afternoon and report back.

AE_Racer

iTrader: (1)

Here’s the sensor check screen with the key on so you can see the tps voltages




edit: dunno why it turned it sideways

AE_Racer

iTrader: (1)

Walbro 255 installed, same result. Verified jumping the pump via diag port does not help. Car is also seeing 14.0v when I keep it running, latest idea was maybe the alt had taken a crap. Im really lost now.

could that fuel pump “speed” relay have anything to do with it? The one in the box near the rad support. I dont have a helper to see if I could hear it clicking or anything.

This sucks, car has been great to me for over a year lol

DaleClark

iTrader: (55)

It's possible. May want to get a jumper and bypass the fuel pump resistor relay to run it at full 12v. Probably need to dig around in the shop manual and figure out the wiring to do so.

If you actually look at the gauges on the commander does it show the water temp and air temp are correct? Like if it's 70 degrees out side and the car is cold, they should both be around 21 degrees Celsius on the commander.

Dale

AE_Racer

iTrader: (1)

Yep air temp and water temp seem ok. Map shows around -22mmhg

Red94fd

iTrader: (5)

Man... the only one time something like this happened to me was when i was messing with the pfc trying to put it back in its place, I found one wire (black) almost broken.
besides that

AE_Racer

iTrader: (1)

Well, unfortunately i'm leaving for work and wont be back til early feb. But I did recently remove the apexi rsm, and thinking back I did have to reconnect some wiring down there. This was some time before the problem popped up but can't remember when exactly, definitely within the month of december. The wires tapped for that were ignition power, a ground, rpm, and speed. I will check that out when i get back.

DaleClark

iTrader: (55)

^I bet that's it. Probably a broken connection. That RPM connection being bad could cause you some problems.

Dale

AE_Racer

iTrader: (1)

Took a quick look since im still home for tonight. The main wire I remembered reconnecting seems to be ignition power, and it looks good. Still no change after verifying and reconnecting. Will dive deeper when I get back.

teebeekay

iTrader: (4)

I was thinking something along the lines of crank position sensor (RPM) as well. One of my sensors is loose or corroded that when it rains or is humid the car sometimes won't turn over. I keep a long screw driver in the car to tap the NE/G harness plugs and it fires right up every time.

I know it's a ghetto fix but it happens maybe 2 or 3 times a year and I've been too lazy to dig all the way in there to fix the connection.

AE_Racer

iTrader: (1)

I will give that a look as well. Gotta be something im missing. Its odd that it seemed to progressively get worse. May try unhooking the exhaust from downpipe and open intake at TB to make sure no restrictions anywhere. Has a muffled midpipe though no cats. Any chance the turbos could have failed in a way to restrict the exhaust enough to choke it out? Just thinking out loud.

DaleClark

iTrader: (55)

If the turbos had a catastrophic failure you'd know it. I had a buddy break the turbine wheel off on one of his turbos, made a HUGE noise and HUGE oil smoke. That's the only way they would fail to where there was a restriction.

Low speed/idle you should be able to run with a huge exhaust restriction. I doubt that's an issue. Intake being plugged is a possibility but I doubt it, I don't think it would start at all if it's getting no air.

You still have the thermowax right? If so your TB should be cracked open for a high idle so that rules out the ISC.

Dale

AE_Racer

iTrader: (1)

Thanks so much for your assistance.

I'm second guessing if I left a paper towel or something in the intake lol but that would have been some time ago when I had any of that apart.

The only thing I've removed/blocked off is the air pump and the ACV. I don't think my car has ever done the 3000rpm cold idle or whatever, but it does shoot up to 1500rpm like it normally would. Unplugging the ISC resulted in it starting up to 8-900rpm and then dies like usual.

Molotovman

iTrader: (49)

Pull the charge pipe apart at the intake elbow, that will rule out restriction across the IC (I remember a thread similar to this where some dude pulled out childrnes' underwear that was used as a rag from his IC/charge pipe, LOL!). If that makes no change see if you can get it to run off of starting fluid.

TomU

iTrader: (11)

If it starts on ether and then dies, that generally means you have a fueling issue

AE_Racer

iTrader: (1)

Thanks for the additional suggestions guys. Ill pull off the intake pipe and then try starting fluid if nothing there. At that point I suppose ill be pulling it apart and checking the primary injectors. Open to other suggestions, still over a week before im back home to try things out.

Tom93R1

iTrader: (2)

Dale earlier mentioned Fuel Pump resistor, that's my guess. When that goes bad the car will start and idle for a second then die because the fuel pump shuts off.
If you have anybody that can help listen to the fuel pump you should be able to verify if that is what's happening.

AE_Racer

iTrader: (1)

does jumping the pump via the diagnostic port bypass the resistor? If so ive tried that. Also I can barely keep the car running by constant throttle blipping, which would tell me its getting some kind of fuel

AE_Racer

iTrader: (1)

Back home finally. Pulled off tb elbow just to give it a shot. Jump box is about dead so gonna try some other things later. Here’s a video of the issue in case something sticks out to anybody.

AE_Racer

iTrader: (1)

Ohmed the fuel pump resistor, came out good per fsm. Jumped the pins in the fuel pump relay to bypass the resistor (puts pump on high speed). Still no change. Will work on supplying constant voltage to pump just to make sure its not shutting off

Tom93R1

iTrader: (2)

Once you can get it started, can you have somebody spray starter fluid or something similar around the manifold/turbo area to look for a big intake leak? A major intake leak can cause similar issues to a fuel issue

AE_Racer

iTrader: (1)

Help isnt easy to come by unfortunately. Hard wired pump straight to battery and grounded from the connector. Pump definitely running, no change.