I guess you can tweak fuel pressure with the stock unit? That's what he told me anyway. I didn't think you could.
Can I get a regular fuel pressure gauge? Or do I need an aftermarket regulator?
What is stock pressure like 39 or 40?
Cobra lost power after installing Crane 2031 cam
- Thread starter SVTtripleblack
- Start date
I guess you can tweak fuel pressure with the stock unit? That's what he told me anyway. I didn't think you could.
Can I get a regular fuel pressure gauge? Or do I need an aftermarket regulator?
What is stock pressure like 39 or 40?
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legalize420
Active Member
any fuel pressure gauge. you can get a handheld gauge at a parts store. the other options would be a rail mounted gauge that attaches to the schrader valve or a gauge with a sender mounted in view of the cabin. stock pressure should be between 38-40 with the vacuum line disconnected and should drop down to about 32 with it connected. i dont think you could change the pressure on the stock regulator but i cant say for sure.
95riosnake
Member
SGS Automotive and Performance
901 Range End Road
Dillsburg PA 17019
717-502-8880
That's the only contact info I have for them. gmkiller has had his car tuned there a few times, shoot him a pm, maybe the number has changed.
rj95svt
Member
I imagine that you car i not cranking because it is flooding not because of the computer needing reset. If you hold the throttle wide open when turning the engine over it will probably crank.
I would try checking the plugs to see if they have some unburnt fuel on them.
It sounds like the car is just runnung extremely rich but I am not sure why.
I would try checking the plugs to see if they have some unburnt fuel on them.
It sounds like the car is just runnung extremely rich but I am not sure why.
I think you're headed in the right direction with this. That might explain why my car started for a short time after letting it sit overnight. The plugs might have dried out enough to get a good spark. The only thing I don't understand is that my fuel pressure was bumped up and looked pretty good on the dyno without the chip. It was around 12.5 to 1, which might be a little rich, but it wouldn't keep my car from starting. I wonder if resetting the battery changed my fuel pressure enough to keep it from starting? Man, I could kick myself for resetting the pcm. I should have just left it alone untill I got the car retuned. Well since I'm a AAA member, I'm going to have it towed for free to the dealer. I'll ask them to check fuel pressure and adjust it back to stock before they spend any time on costly diagnostics. I could buy a fuel pressure regulator and check it myself, but what if that's not the problem? I don't want to spend money on something I will never use again and then have it not solve the problem. Plus I would need to order one and then wait for it to ship. Since it's free to tow, and I need the car inspected by the end of May, I will let the tech handle it at the local Ford dealer. That way if it turns out to be another problem they can diagnose it.
StinkinLincoln
Member
StinkinLincoln
Member
regulator
http://store.summitracing.com/partdetail.asp?CP=1&part=BBK-1707&N=700%200&Ntt=BBK~1707%20or%20BBK~1706&Ntk=&rsview=sku&Ns=P_SRE_DisplayPrice|0
guage
http://store.summitracing.com/partdetail.asp?part=SUM-800160
i needed a couple fitting from the local hardware so the gauge didnt hit anything.
i think i have a 45 degree elbow and like a 1/2 to 1in straight piece.
i dont know how they adjusted FP manually w/ the stock regulator...
its very easy to do w/ the adjustable regulator. hook up a vaccume line to the intake a turn the screw in to add more fuel, thats easy.
the dealership cant reset the FP back to stock, any more than you can, its OBD1 (eec4) which is limited to the test port in the engine bay and all you get it codes.
OBD2 uses the DLC and much more is accessible.
do it yourself! lol it will be worth it in the end, it helps, you will be able to diagnose problems in the future easier, trust me, experience from starting from scratch and jumping into a stroker h/c/i, you learn alot, and spend alot more LOL
http://store.summitracing.com/partdetail.asp?CP=1&part=BBK-1707&N=700%200&Ntt=BBK~1707%20or%20BBK~1706&Ntk=&rsview=sku&Ns=P_SRE_DisplayPrice|0
guage
http://store.summitracing.com/partdetail.asp?part=SUM-800160
i needed a couple fitting from the local hardware so the gauge didnt hit anything.
i think i have a 45 degree elbow and like a 1/2 to 1in straight piece.
i dont know how they adjusted FP manually w/ the stock regulator...
its very easy to do w/ the adjustable regulator. hook up a vaccume line to the intake a turn the screw in to add more fuel, thats easy.
the dealership cant reset the FP back to stock, any more than you can, its OBD1 (eec4) which is limited to the test port in the engine bay and all you get it codes.
OBD2 uses the DLC and much more is accessible.
do it yourself! lol it will be worth it in the end, it helps, you will be able to diagnose problems in the future easier, trust me, experience from starting from scratch and jumping into a stroker h/c/i, you learn alot, and spend alot more LOL
Thanks for the links I appreciate it. I have to have the car inspected anyway, so I will tell the Ford Tech about it and see what he says. You must be able to adjust the fuel pressure with the stock unit. How was it done in the first place? 
I don't have an afpr on the car, and I sure as h-- know he didn't do it through the pcm. Sure you can't tell what your adjusting it to without a pressure gauge, but you can use something like a dyno as a guide to see where your A/F ratio is and adjust from there. (Lol, Which I don't recommend because look what happened to me). I don't see why the tuner would've lied about that. If the A/F ratio was dead on and needed no adjustment, he would have said so. He did last time. Plus, I'm not even sure this is the problem yet. I hope it is, because it would be an easier fix than tracing a bad connection or replacing a computer.
Thanks for all the suggestions and help guys. I'll let ya all know how it pans out. I just want it running so I can get it properly tuned and hit the track. The weather is getting to nice to be without my stang.
I don't have an afpr on the car, and I sure as h-- know he didn't do it through the pcm. Sure you can't tell what your adjusting it to without a pressure gauge, but you can use something like a dyno as a guide to see where your A/F ratio is and adjust from there. (Lol, Which I don't recommend because look what happened to me). I don't see why the tuner would've lied about that. If the A/F ratio was dead on and needed no adjustment, he would have said so. He did last time. Plus, I'm not even sure this is the problem yet. I hope it is, because it would be an easier fix than tracing a bad connection or replacing a computer. Thanks for all the suggestions and help guys. I'll let ya all know how it pans out. I just want it running so I can get it properly tuned and hit the track. The weather is getting to nice to be without my stang.
legalize420
Active Member
someone correct me if i am wrong but the stock regulator is NOT adjustable. lets say it was and he did adjust it that would not keep the car from starting and neither would disconnecting the battery overnight. what happens when you try to start it? i would try cracking the throttle blade open a little bit with the stop screw and see what happens.
I tried adjusting the TB stop screw already. I also tried checking all of my connections around the distributor and around the computer. It didn't make a difference. The car is just cranking and it won't fire. I got it to fire a few times, but it usually stalls after a couple of seconds. If the pcm sensed that the fuel pressure was too high, I would imagine that would keep it from starting.
I dunno? The only thing I can say is that after I unplugged the battery, I started having problems. I doubt it, but who knows, maybe he removed the chip with the battery still plugged in and then made adjustments. Maybe when I reset the computer, those adjustments made the car go haywire?
The point is, I don't know enough to get this thing running. I tried everything I could think of and nothing has helped so far.
StinkinLincoln
Member
they could not have adjusted it manually, there is nothing that is movable on the regulator. chances are the plugs are fouled, change the plugs first. check for spark by grounding a plug w/ a spark plug wire on it and turn it over and look for spark.
fouled plugs keep them from firing...
hold the pedal at WOT when cranking, it keeps the injectors from firing.
fouled plugs keep them from firing...
hold the pedal at WOT when cranking, it keeps the injectors from firing.
rj95svt
Member
I agree
This is what I would do but only hold it wide open after you have already tried cranking it normally.
I tried holding the gas pedal down while starting. I didn't notice any difference. Why would the plugs be fouled if the car isn't running really rich? My A/F on the dyno was about 12.3/12.5 to 1. That isn't too bad. I will check them, but I was just wondering. I just replaced the plugs with fresh ones three weeks ago. I'll pull them after work and see what they look like. Any guesses as to why they are getting fouled?
rj95svt
Member
The very first thing I would do is check a plug. It could just be running extremely rich at idle and good everywhere else. It's hard to say without seeing it really.
It could be a spark problem. If you haven't checked the spark it's hard to say. Weak or no spark could also cause the fuel smell.
If there is fuel, compression, and fire it will run. If there is to much fuel it will usually run just not well.
It could be a spark problem. If you haven't checked the spark it's hard to say. Weak or no spark could also cause the fuel smell.
If there is fuel, compression, and fire it will run. If there is to much fuel it will usually run just not well.
StinkinLincoln
Member
dont know if this has been posted here or not but when it floods like that and wond start try holding the gas pedal to the floor untill it starts and then release it. it stops the injectors from squirting
The stock reg is not adjustable, and one thing to keep in mind is with the adj reg you only ge the additional FUEL at WOT, otehrwise the stock PCM takes over and will adjust the pulse width of the injectors along with feedback from your 02's.
I think the plugs are fouled.... That cam shopuld idle farily well, it may stalk once ort twice upon a nice old start-up but after that should be fine.
I think the plugs are fouled.... That cam shopuld idle farily well, it may stalk once ort twice upon a nice old start-up but after that should be fine.
Thanks, I will try to get it started tonight. I had to go on a small business trip and I wasn't able to work on it. Any ideas why my plugs were getting fouled in the first place? I mean, I know why they are now, because I kept on cranking the car without holding the gas down and soaking the plugs, but why did it happen in the first place? The car might fire now, but I don't want this to happen all the time.
WhiteCobra95
Mod Dude
- May 2, 2006
- 565
- 144
- 74
A couple suggestion and bits of info:
If you have a stock pressure regulator (check!), there is no good way to adjust the rail pressure. It's not technically adjustable. I've seen some people smash the can, thus adding more preload on the spring, which will increase pressure. This is usually done with a socket over the vacuum port and a hammer. This is a total hack and should never be done. You should be able to tell if someone tried this because there will be a whitness mark. I would suggest calling the shop to ask them exactly how they set the pressure. Could the previous owner have installed an adjustable part? Some adjustables do look similar to the stock regulators.
In general, you need to slow down and go back to the basics like some people have suggested: Measure the rail pressure and check the plugs. Put in a new set of plugs and try to start it. If it doesn’t start, pull one plug and see if it's wet or carboned up. It only taks a couple seconds to foul out a set of plugs if the fueling is wrong, but this will give some indication of how rich it really is. If it's completely clean but wet, then you're either missing spark or getting WAY too much fuel. If it's black/wet carbon, then your borderline on fuel and getting a partial burn. This will tell you a lot! Also, watch the rail pressure during the pump prime and during cranking. It shouldn't fall too far below the spec. If you hear the pump shut off and come back on during a single key-on prime, your pump or the pump relay might be crapping out. The rail pressure gauge will confirm this!!!!!!
It sounds to me like your EEC had learned out a lot of fuel in the adapatation memory (idle range). This adapted fuel trim is probably also used with the cold start fuel (I don't know the Ford strategy in detail, but this math is fairly common in the industry). This is probably why it ran fine from the shop and got screwy when the EEC was power-failed. Also, engines are much more forgiving when they're warm compared to cold. A cold start is one of the most dynamic conditions in engine operation. Hot restarts also use a reduced amount of fuel since more of the gas atomizes instead of getting lost to cold ports during a cold start. So it might have only ran well on the first day because it didn’t completely cool down.
In additon, WOT AFR is only loosely reated to idle AFR. If he did actually modify your pressure, he might have solved a WOT fueling issue and screwed up idle fuel flow. So much so that you're getting WAY too much fuel to start.
You mentioned before that you already had a chip. Are you running the right MAF for the ECU without the chip? If the transfer function is different between the two, your air flow measurement might be off. This is really common with modified mustangs/non stock MAFs and the tuner will usually adjust the base fuel maps or MAF characteristic to compensate. (Don't fall for the MAF's calibrated to injectors BS.)
Also, don't mess around too much with the IAC and throttle screws. If it at least idled before, it should idle now even if you have to baby it to get it started. You could potentailly mess-up the idle control from the IAC's air flow side and then you'll have two problem eclipsing each other, which will be really hard to solve.
- Good luck and keep us posted!
If you have a stock pressure regulator (check!), there is no good way to adjust the rail pressure. It's not technically adjustable. I've seen some people smash the can, thus adding more preload on the spring, which will increase pressure. This is usually done with a socket over the vacuum port and a hammer. This is a total hack and should never be done. You should be able to tell if someone tried this because there will be a whitness mark. I would suggest calling the shop to ask them exactly how they set the pressure. Could the previous owner have installed an adjustable part? Some adjustables do look similar to the stock regulators.
In general, you need to slow down and go back to the basics like some people have suggested: Measure the rail pressure and check the plugs. Put in a new set of plugs and try to start it. If it doesn’t start, pull one plug and see if it's wet or carboned up. It only taks a couple seconds to foul out a set of plugs if the fueling is wrong, but this will give some indication of how rich it really is. If it's completely clean but wet, then you're either missing spark or getting WAY too much fuel. If it's black/wet carbon, then your borderline on fuel and getting a partial burn. This will tell you a lot! Also, watch the rail pressure during the pump prime and during cranking. It shouldn't fall too far below the spec. If you hear the pump shut off and come back on during a single key-on prime, your pump or the pump relay might be crapping out. The rail pressure gauge will confirm this!!!!!!
It sounds to me like your EEC had learned out a lot of fuel in the adapatation memory (idle range). This adapted fuel trim is probably also used with the cold start fuel (I don't know the Ford strategy in detail, but this math is fairly common in the industry). This is probably why it ran fine from the shop and got screwy when the EEC was power-failed. Also, engines are much more forgiving when they're warm compared to cold. A cold start is one of the most dynamic conditions in engine operation. Hot restarts also use a reduced amount of fuel since more of the gas atomizes instead of getting lost to cold ports during a cold start. So it might have only ran well on the first day because it didn’t completely cool down.
In additon, WOT AFR is only loosely reated to idle AFR. If he did actually modify your pressure, he might have solved a WOT fueling issue and screwed up idle fuel flow. So much so that you're getting WAY too much fuel to start.
You mentioned before that you already had a chip. Are you running the right MAF for the ECU without the chip? If the transfer function is different between the two, your air flow measurement might be off. This is really common with modified mustangs/non stock MAFs and the tuner will usually adjust the base fuel maps or MAF characteristic to compensate. (Don't fall for the MAF's calibrated to injectors BS.)
Also, don't mess around too much with the IAC and throttle screws. If it at least idled before, it should idle now even if you have to baby it to get it started. You could potentailly mess-up the idle control from the IAC's air flow side and then you'll have two problem eclipsing each other, which will be really hard to solve.
- Good luck and keep us posted!
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