Fore 4v 1 LE

[MG0h3]

I considered telling him to bump the fuel pressure but he’s tuned as is.

Maybe the tuner thinks he’s at 40 running and tuned it as such.


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[03' White Snake]

I considered telling him to bump the fuel pressure but he’s tuned as is.

Maybe the tuner thinks he’s at 40 running and tuned it as such.


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His tunes crap as is anyway. I’d bump the pressure and go over everything and try again.

 

[MG0h3]

His tunes crap as is anyway. I’d bump the pressure and go over everything and try again.

I sense some reluctance to abandon the shop that was paid.


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[03' White Snake]

I sense some reluctance to abandon the shop that was paid.


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I agree. He doesn’t need to bad mouth them. He needs to go over the car 100% and diagnose the problem, then make them aware of their mistake. If he wants to go for compensation or to have them fix it, it’s on him.

If everything on the fuel system is working correctly, it’s a pretty simple setup. Do the pumps pump fuel at pressure? Is the filter on correctly, is it clogged? Does the regulator build pressure? Does the regulator build pressure 1:1 with boost? Injectors. Return line go to the tank? Then it’s wiring, I’m not 100% sure how FORE does this, but many others use simple relays, power from battery, and signal from FPDM. Power from relays to pumps. Again, very simple.

Just need to go over everything 1 by 1 and check its function. That’s how I troubleshoot. Isolating 1 thing at a Time.

 

[Davisenvy]

Both tunes from two different tuners are doing the same thing. I’ll go out this afternoon and really go over the things you have mentioned. Thanks for your help

There’s no reluctance to abandon the shop, just reluctance to put their name out there. There’s no way they didn’t know my car was doing this BOTH times they called me and said they had the car running perfect. Also, there’s bad mouthing and sharing a negative experience where a shop takes 6 weeks, 2 visits, $3,900 and the car still runs like trash after a fuel install and dyno tune.


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[Davisenvy]

Trying to upload some pics. Hope it works.

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[MG0h3]

Curious where they got the vacuum source from.

Have you told the tuner that the car isn’t running right? They should be asking for data logs.


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[Davisenvy]

Yes, I have done tons of data logging and every revised file they sent me made things worse. This is when I took the car back the second time. Now they're "brainstorming" onto what the problem could be. I've resigned to the fact that they either can't fix my car or don't want to fix my car.

Should my car have higher than 30 psi fuel pressure when running? Should I have a FPDM? If so, where would it be?

 

[MG0h3]

Fpdm is in the trunk. Drivers side behind liner.

Some keep it to wire the car to prime like factory. Otherwise, your pumps run full time with the key on.

Neither way should cause a driveability issue.

My tuner had me set my base pressure to 50. It’s around 40 while running. Maybe there’s a communication error about fuel pressure running vs not.

A quick blip of the throttle should drive the fuel pressure up to your base; 40 in your case.


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[Davisenvy]

OK, now this part is making a little sense. I don't see a FPDM and my pumps run constantly.

I would feel differently about a communication error if they hadn't had my car so long on 2 different occasions.

They are telling me it's a TPS problem, but I'm not so sure. I'm watching the "how to" by Danny Johnson on Justin SVT's car.

 

[MG0h3]

I’d ask for the FPDM back. It’s yours and you can sell it.

I really struggle with how you’ve developed some random problem unrelated to their work. That just doesn’t happen.

I think that they don’t know what they’re doing so they’re grasping at straws.

If it is a TPS problem, why hasn’t it been resolved? It’s a simple part that’s easy to test.

You need to start challenging them or tell them to put your car back how it was and refund 100% of the money.


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[Davisenvy]

Yeah, we'll have this conversation tomorrow. I'll report back what I find out. Thanks for your help.

 

[bird_dog0347]

What is that unplugged connector (grey) on top of the driver's side fuel rail? Should it be unplugged?

 

[03' White Snake]

Yeah, we'll have this conversation tomorrow. I'll report back what I find out. Thanks for your help.

Another thing to check, is the boost bypass is working. That’s the round thing on the right rear of the blower. With car off, look where the rod is. Start the car, did it move? Hit the throttle and watch the rod, you should see it closing and opening when you let off the throttle.

 

[2003RedfireVert]

What is that unplugged connector (grey) on top of the driver's side fuel rail? Should it be unplugged?

It’s the frps. Mine is plugged in. I run the system dead headed which is how a lot of people run with stock rails. It retains the frps, which I wanted to do.

I don’t like how they plumbed your lines, OP. I’m sure it should work but not how I would done it. To each his own.

 

[4sdvenom]

Where is your vacuum/boost reference line to your regulator sourced from? Make sure it's from a location that will provide vacuum at idle and part throttle and will provide boost pressure to the regulator when in boost. Make sure it isn't kinked or have a crack/leak in it.

 

[01yellercobra]

FWIW, 30psi isn't too low when running. It's actually pretty common. Especially if the vacuum line is hooked up. I set mine to 40 with the line disconnected. It drops to about 32 with the vacuum line connected. As it should with the vacuum reference. Everyone might be thinking of the 39psi delta between the top and bottom of the injectors. Vacuum vs boost pressure.

If you still have the stock ECU the FRPS should still be in place. It's good to keep in use as the ECU can use it as a reference if you decide to change the base pressure. No need to tweak the tune. If the ECU is still looking for it and it's not there, that could cause problems.

Even if the regulator is hooked up to the wrong source the car should run smooth. It'll just drop fuel pressure under boost. Learned that one on my buddies car.

My apologies if any if this has already been said. I just looked at the pics and skimmed everything else.

 

[PC03GT]

The BAP and VMP email tune is what I had going into this project and the car ran like a top. I figured a dyno tune would be better than an email tune so I had a shop a little closer to home do the dyno tune and fuel system. I want to make sure this shop can or is able to fix the problems before putting their name out there. $3,900 later has me a little disappointed .

Sorry OP for hijacking your thread.

That's insane dude. I just had a longblock assembled and installed, the labor was 3gs

 

[Davisenvy]

Are you sure the gray plug is the frps? My EGR is deleted and thought the gray plug went to the EGR. As far as the ECU, I can only assume its stock. It only had a ported Eaton with a BAP, Accufab TB, SCT 2600 MAF and JLT intake.

I'll go out this afternoon and do some more looking around. It's been a busy weekend.

Yes, I did pay a lot for this project. I don't have a whole lot of free time and this place has a good reputation with 03,04 Cobras. I just mainly wanted a dyno tune and got talked into this mess.

 

[cj428mach]

Wow what a disaster. The fuel system isn't the problem, watch your fuel pressure at start up. I assume it's rock solid which is all the Fore can do. You assume the shop set the fuel pressure to stock so all you have to do is log the pid fuel pressure drop across injectors, it should be 39-40lb.

I feel bad for people that pay to get their cars hacked up like this. In my opinion any street car should retain the FPDM even in a return setup, anything else is lazy.