Running rich....what could go wrong?

[DrtyRat]

OK....I ask this question knowing a few of the obvious answers:
Detonation, fouled sparkplugs, bad gas mileage.
The reason I'm asking is b/c I'm trying to trouble shoot what could be wrong w/my SR. I'll try to keep it short while explain the current prob. Basically, my motor has been difficult to start for sometime, when I cold start it I have to press/pump the gas all the way down for it to start, and once it starts it will idle pretty smoothly, and I was able to get full boost w/no problem. I don't have too much of an issue once it starts. To rectify this prob. I cleaned 1st and then replaced the MAF, fuel filter,cone filter, had the coil packs checked, spark plugs replaced and gapped to 28/29(I don't recall which one, but all are the same), and I replaced the coolant temp. sensor. None of this has helped. After having it like this for some time, I got it started one day, got on it (boost) and a new prob. arose. When I'd be @ WOT and hit 4k rpm it would start breaking up until I let off of it. I can go @ 50% throttle and it will boost and hold w/no prob, although not @ full boost (approx. 5lbs). I've had the car checked for boost leaks and again no problems there. What could it be?
Now back to the original ?...I know I'm running rich b/c my timing has been adjusted to compensate for my atmospheric bov, so that the car doesn't stall. I'm just curious what else could I try to replace on my limited knowledge of cars? I want to know what else could go wrong/get messed up by it running rich. I tried to have my mechanic diagnose the prob. but he doesn't do this full time, just in his very little spare time, and he doesn't have the time to really trouble shoot. If I cant fix it myself I will pay to have a "shop" look at it. I don't mind spending the money to have it done right.
engine/mods...
S14 SR, FMIC, 3" downpipe, 3" test pipe, blitz nur spec exhaust, AEM universal cone filter, cometic hg, arp headstuds, Supra TT fuel pump, and mbc set to only 9lbs, everything else is stock (injector and such)
I forgot to add the my ecu has thrown a code only once,car was sputtering, and wouldn't rev w/o breaking up, and I didn't see what code it was giving off. At the point the CEL came on, I turned off the car, started it again, and it didn't come back on.
Any help would be appreciated...thanks

[luisgonz]

I didnt read it but, Make sure you dont have someone working on it that thinks they know it all.

[DrtyRat]

I didnt read it but, Make sure you dont have someone working on it that thinks they know it all.
Agreed, I only let one person work on it but he's kinda pressed on the time he has to look at it, and doesn't have time to trouble shoot my problems.

[unicoladron]

1. you should check that ecu code that you never checked.
2. unplug your o2 sensor, see if it still behaves the same. i had a similar problem once and it turned out to be a bad o2 sensor.
3. maybe set yoru timing back to base timing and perhaps if possible setup your bov to recirc.

[luisgonz]

Check this stuff too^^^^^^^^^^

Please post if you can. Whats your timing set at. It sounds like it could be a rubbed wire. Please check again. What kind of bov are you running. Some are faulty from factory.

[DrtyRat]

Please post if you can. Whats your timing set at. It sounds like it could be a rubbed wire. Please check again. What kind of bov are you running. Some are faulty from factory.
Don't timing but I'll try to find out, and my BOV is a HKS SSQV. You know now that you mention rubbed wire, I recall that on my MAF harness there is one slightly exposed wire. I've thought about it being the cause, but have yet to tape it. I don't know if it would arc, and I haven't taped it b/c I guess it just seems too obvious, for it to be causing the prob.....that last statement just made me sound like a blithering idiot!

[johngriff]

TPS sensor
Coil pack harness going garbage.
Maf wiring possible
Bad Maf (internal solder joints)

Test continuity of all wires on c/p harness.
Test continuity of AFM signal wire

[DrtyRat]

John,
MAF was replaced and the coil packs checked out, meaning they had good spark , and if iirc my mechanic checked continuity on the cp harness and it checked out ok. I'll have to check the FSM for the AFM signal wire location. What should I be looking at to test it. I've been wanting a digital multi meter for some time, but I'm not sure if this is necessary. Could it be done w/a test light, or do I need to check voltage?

[DrtyRat]

1. you should check that ecu code that you never checked.
2. unplug your o2 sensor, see if it still behaves the same. i had a similar problem once and it turned out to be a bad o2 sensor.
3. maybe set yoru timing back to base timing and perhaps if possible setup your bov to recirc.
In regards to the O2 sensor, I did some research and found out that it doesn't effect the car @ WOT, so it wouldn't cause it to break up like it has been doing. Then again, it wouldn't hurt to check it out.

[steve shadows]

I didnt read it but, Make sure you dont have someone working on it that thinks they know it all.

but I do...:cj:

Running rich....what could go wrong?

Im with John on this.

02 doesnt matter its a fucking joke on older nissans. 02 feedback only has a big effect on PFCs in my experience.

People on here fail.

This sounds like it could also be a simple ignition ground problem, ie the ignition ground on the back of the coil pack harness to the head.

This needs to be bolted to the back of the head and the firewall (to back of head with 12mm nissan bolt) stubby.

1. Maf
2. Injector O-rings
3. check fuel pressure
4. boost leak
5. ignition ground
6. coilpack failure
7. ecu area wiring all fucked to shit

there one of those is your answer

if not Ill give you a free cold stone icecream when I see you

I will never see you hopefully

so you will never get it

good luck and god's speed

last time this happened to me I sold my car and bought a huffy *jk(but its funnY

[johngriff]

Yes, a digital multi meter is probably the MOST INVALUABLE TOOL YOU WILL EVER BUY IN YOUR WHOLE LIFE.

If you don't have one, and just read this BUY ONE. THEY ARE LITERALLY $3 F#$(* Dollars at harbor freight

You test for resistance in a wire, basically checking how "clean" the voltage is coming across the wire. It will help you pinpoint bad connections, like bad pins, or solder joints.

[DrtyRat]

there one of those is your answer

if not Ill give you a free cold stone icecream when I see you

I will never see you hopefully

so you will never get it

good luck and god's speed

last time this happened to me I sold my car and bought a huffy *jk(but its funnY
lol....i happen to have a bunch of buy one get one free coupons, so if one of those is the problem then 1 "gotta have it" birthday cake remix is on me.
Yes, a digital multi meter is probably the MOST INVALUABLE TOOL YOU WILL EVER BUY IN YOUR WHOLE LIFE.

If you don't have one, and just read this BUY ONE. THEY ARE LITERALLY $3 F#$(* Dollars at harbor freight

You test for resistance in a wire, basically checking how "clean" the voltage is coming across the wire. It will help you pinpoint bad connections, like bad pins, or solder joints.
I actually wanted to get a good one, but I wasn't sure if it was neccessary. I have a HF right in the shopping center where I work so I'll pick one up this week.

[DrtyRat]

Im with John on this.

02 doesnt matter its a fucking joke on older nissans. 02 feedback only has a big effect on PFCs in my experience.

People on here fail.

This sounds like it could also be a simple ignition ground problem, ie the ignition ground on the back of the coil pack harness to the head.

This needs to be bolted to the back of the head and the firewall (to back of head with 12mm nissan bolt) stubby.

1. Maf
2. Injector O-rings
3. check fuel pressure
4. boost leak
5. ignition ground
6. coilpack failure
7. ecu area wiring all fucked to shit

there one of those is your answer

if not Ill give you a free cold stone icecream when I see you

I will never see you hopefully

so you will never get it

good luck and god's speed

last time this happened to me I sold my car and bought a huffy *jk(but its funnY

OK....
I checked the voltage to the cp and all of them checked out w/an 11.5x +, MAF checked out w/the same votage and I checked the ground to the firewall (I used it to test the voltage from the coilpacks) and it was good. Boost leak has already been checked. ECU wiring is fine. Where is the ignition ground?
1. you should check that ecu code that you never checked.
2. unplug your o2 sensor, see if it still behaves the same. i had a similar problem once and it turned out to be a bad o2 sensor.
How do I check the ecu code when the CEL doesn't come on anymore? I unplugged the O2 just to see if that was the problem and it had no effect on it.

[DrtyRat]

SR guru's any input for me? ^^^^^^

[fakts13]

if you have fsm, it will tell you how to put the ecu in self-diagnostic mode (i forget exactly, but it has to do with the idle screw on the ecu and turning it full one way, then the other), or you can find a local nissan shop to pull the code off the consult port (assuming your consult port was wired correctly when the swap was done) and is the method I prefer.

[69datsun510]

If the motor is hard to start first thing when cold, it sounds like your fuel pressure is bleeding down. I would check your fuel pressure regulator and injectors. Sure sounds like you have a bad injector leaking down, or regulator not working correctly, keeping the pressure at the correct level. Sounds like you have checked a lot of things out, but this area. Give it a try and see where it gets you. Good luck

[DrtyRat]

If the motor is hard to start first thing when cold, it sounds like your fuel pressure is bleeding down. I would check your fuel pressure regulator and injectors. Sure sounds like you have a bad injector leaking down, or regulator not working correctly, keeping the pressure at the correct level. Sounds like you have checked a lot of things out, but this area. Give it a try and see where it gets you. Good luck
How do I check the FPR, short of buying a new one? As far as the injectors go, I was thinking about sending them to DeatschWerks to have them rebuilt. You say the fuel pressure is bleeding down, but my fuel pump works fine, could I be missing something else that could effect this?

[Landers]

so how is the ecu coming did you check for codes yet???? Also, have you ever messed with your knock sensor??? Knock sensor wouldnt cause a hard start though.....How do you know your fuel pump is working correctly?

[DrtyRat]

so how is the ecu coming did you check for codes yet???? Also, have you ever messed with your knock sensor??? Knock sensor wouldnt cause a hard start though.....How do you know your fuel pump is working correctly?
My fuel pump comes on w/no prob. when the key is in the on position. It was also checked w/a volt meter and it was fine. Haven't had a chance to check out the ecu code. I'll try today. OH, and I've never messed w/the knock sensor.

[69datsun510]

How do I check the FPR, short of buying a new one? As far as the injectors go, I was thinking about sending them to DeatschWerks to have them rebuilt. You say the fuel pressure is bleeding down, but my fuel pump works fine, could I be missing something else that could effect this?

You need to get a FSM. You need a fuel pressure gage, by placing it in several locations, you can tell you where your leak is occurring or if the fuel pump is making enough pressure. Also check your vacuum hose going to the FPR, make sure it is a tight fit for the hose. You can cut a small amount off the vacuum hose to get to the original hose diameter or replace it if old and hard. Yes you could just buy a new FPR and rebuild the injectors or get a known good set and FPR from a friend's car. If you remove the fuel rail with the FPR and injectors in it, it's a quick, easy swap. Ok, maybe a little hard getting to the little nut holding the rail back by the FPR, use a magnet so you don't drop it. You do have friends with 240's right?

[DrtyRat]

You need to get a FSM. You need a fuel pressure gage, by placing it in several locations, you can tell you where your leak is occurring or if the fuel pump is making enough pressure. Also check your vacuum hose going to the FPR, make sure it is a tight fit for the hose. You can cut a small amount off the vacuum hose to get to the original hose diameter or replace it if old and hard. Yes you could just buy a new FPR and rebuild the injectors or get a known good set and FPR from a friend's car. If you remove the fuel rail with the FPR and injectors in it, it's a quick, easy swap. Ok, maybe a little hard getting to the little nut holding the rail back by the FPR, use a magnet so you don't drop it. You do have friends with 240's right?
I have a copy of the FSM on my comp. so I'll have to look at it. Car was already checked for vacuum leaks. I also tried resetting the ECU but nothing happened. The adj. screw turned clock wise but never tightened up. Also, according to the research i did, I should've seen the CEL light in the dash, or the ECU come on but nothing. My CEL light on my cluster works, but didn't flash, so no code. As far a "friends" w/240's, the only one I have has an rb in it. I don't hang out w/the 240 crowd. I'm a married man w/a kid, a 60hr a week job, so my free time is spent w/family.

[AntiVtec]

Check your oil and see if it smells alot like gasoline. If it does you could have a leaky injector/s, fuel pressure is too high, or some fuel system clog. Its a simple test but it might point you in the right direction.

[DrtyRat]

Check your oil and see if it smells alot like gasoline. If it does you could have a leaky injector/s, fuel pressure is too high, or some fuel system clog. Its a simple test but it might point you in the right direction.
What's up Laz, this is DrtyRat(Joe) from sfl240sx. I think I'm just gonna have my injectors done by DeatschWerks, just to be on the safeside, thanks. BTW, I'm gonna try to get around to installing the sparco pedals today.

[69datsun510]

I have a copy of the FSM on my comp. so I'll have to look at it. Car was already checked for vacuum leaks. I also tried resetting the ECU but nothing happened. The adj. screw turned clock wise but never tightened up. Also, according to the research i did, I should've seen the CEL light in the dash, or the ECU come on but nothing. My CEL light on my cluster works, but didn't flash, so no code. As far a "friends" w/240's, the only one I have has an rb in it. I don't hang out w/the 240 crowd. I'm a married man w/a kid, a 60hr a week job, so my free time is spent w/family.

I can relate to the family and 60hr a week job, me too. Wife is on me about getting some of my car projects done. So I can sell one and get her car painted to sell. I still have to fix the A/C on her car damn Autozone A/C compressor went bad after 2 weeks. I had to wait 3 months for a warrant compressor to come in. I finally finished the S14 today. I hope you get the car fixed. I will keep an eye on the thread to see what the problem end up being. So, post when you get it fixed. Good Luck!!

[AntiVtec]

What's up Laz, this is DrtyRat(Joe) from sfl240sx. I think I'm just gonna have my injectors done by DeatschWerks, just to be on the safeside, thanks. BTW, I'm gonna try to get around to installing the sparco pedals today.

Hey whats up Joe, hope those pedals look sweet. The deatschwerks injectors is a good idea, ive had 550's and 740's from dave and never had a problem. Good luck with the car and keep us posted.:2f2f: