Fuel cut and boost leak test

[Momar]

Well, I bought this car not running. I repaired head(bent valves) and installed stainless valves. I have installed a 20g, walboro255, 650cc injectors, and a 2g maf. I installed a translator from my friend, but it is not working so back to 2g maf for now.

I am hitting boost cut, but I am not sure if it is just from the flow of the larger turbo, or if I have other problems(I know that the 2g maf is not an exact match to the 650's). I am hitting the cut running only 10lbs of boost. I made a boost leak tester today, and hooked it up. The first leak was major. It was the lower ic hose. I fixed that, and a couple smaller ones. Took it for a test drive and it still cuts but spools much quicker. Now not until almost redline though instead of 5000 rpm. I tried turning the boost up and it hits the fuel cut hard at much lower rpm. Still hardly makes it past 10psi before this happens.

I will say that when I did the boost test I could still hear some air leaking through the engine, but I didnt set the engine at any specific point, so I think I am going to try it again and try to get it set so that valves are not overlaping and see if I can come up with anything else.

I just wonder what you guys think with my mods should I be hitting boost cut at that low of boost? I know that turbo flows pretty good, but I dont even really have it turned up. I plan on getting another translator and wideband eventually as well as other mods, but on a budget. I figured I should be safe to run over 10 pounds of boost though if I can get it to stop fuel cutting.

If this turbo really does flow enough that it is fuel cutting right now with the 2g maf, will adjusting a translator for the 650cc injectors be enough to avoid it?

Thanks
Ben

 

[Momar]

First, car didnt have a lower timing cover when I recieved it, so I dont have one to put back on.

And, no you cant turn the motor so that all the valves are closed, but if you have it turned so that at least one set of valves are closed on each cyl, then you dont have overlap, and you dont blow your pressure right out of the exhuast.

Plugs are NGK BPR6ES.

I understand why boost leaks make you hit fuel cut faster. That is why I spent all the time I did fixing mine. It has seemed to help raise where I hit it, but I still hit fuel cut.

I already have a translator, and a gm maf. The translator isnt functioning properly, but I already talked to fullthrottlespeed and they said that they should be able to fix it. So when I get that repaired, I am going to install it to adjust for my injectors.

As far as your figure of 650's being 44% bigger than stock, the instructions for the translator show to pull 30% fuel for 650's. Is it really that much you need to pull out? 450 is approimately 30% of 650. But you can figure that 250 is about 56% of 450 which leaves your 44%. I am a little confused on which one should get me close. I will probably start at the 30% number when I get the translator installed, but it would be great if 44% is right because that would give me more room.

 

[NOSLO2PT0]

First, car didnt have a lower timing cover when I recieved it, so I dont have one to put back on.

Those are easy to find. I suggest grabbing one somewhere and throwing it back in.

As far as your figure of 650's being 44% bigger than stock, the instructions for the translator show to pull 30% fuel for 650's. Is it really that much you need to pull out? 450 is approimately 30% of 650. But you can figure that 250 is about 56% of 450 which leaves your 44%. I am a little confused on which one should get me close. I will probably start at the 30% number when I get the translator installed, but it would be great if 44% is right because that would give me more room.

I stand corrected on the fuel adjustments. My math was WAY off. Yes it's actually about 31% correction.

 

[Momar]

Well, I was able to finally get the car to run without fuel cutting. I had to turn down the boost to get it to stop. It spikes now to around 14 or maybe just under 15, and drops to 12.5ish and levels off. Runs good, but cant wait to run some more boost. Going to try to get translator sent in to be fixed soon.

 

[NOSLO2PT0]

You said you were running 10psi when you were getting fuel cut. I assume you fixed the boost leaks and bumped up the boost?

 

[Chicken Patty]

Well, I was able to finally get the car to run without fuel cutting. I had to turn down the boost to get it to stop. It spikes now to around 14 or maybe just under 15, and drops to 12.5ish and levels off. Runs good, but cant wait to run some more boost. Going to try to get translator sent in to be fixed soon.

I honestly think that sounds about right bro, I remember with the 14B I would get away with about 17-18ish psi before hitting fuel cut. You have a 20G so it seems right. What you need now is to get a tune, then you can run more boost without fuel cut. Good luck bro.

 

[Momar]

Yes, the boost is up from the lowest I ran. I tried 14 and it cut real bad. I had to back it back off till around 12.5ish and it stopped fuel cutting. I am going to try to get my translator sent off this week to be fixed. Then I will be able to use it to tune.

I am also looking at getting an afpr, and maybe raising my fp from the 37 up to around 43 since that is what injectors are rated at anyway. That should also give me a little bit more room when I tune for that on the translator. Does anyone have any suggestions on a decent fpr that wont break the bank?

 

[Chicken Patty]

Yes, the boost is up from the lowest I ran. I tried 14 and it cut real bad. I had to back it back off till around 12.5ish and it stopped fuel cutting. I am going to try to get my translator sent off this week to be fixed. Then I will be able to use it to tune.

I am also looking at getting an afpr, and maybe raising my fp from the 37 up to around 43 since that is what injectors are rated at anyway. That should also give me a little bit more room when I tune for that on the translator. Does anyone have any suggestions on a decent fpr that wont break the bank?

Unless you find one used, the very popular choice lately is the Fuel Lab Regulator. Not sure if you'll consider that breaking the bank, but worth taking a look at.

STM | 90-99 DSM FUEL RETURN KIT | FUELAB FPR AND GAUGE

 

[Momar]

Not to say that I wont spend the money, but so far this car has been an extreem budget build. I only have around 600 dollars in the car. I got the car for free(traded it for a car I planed on taking to junkyard. ). I know I will have to spend some money on it, but just not trying to go overboard. I still plan on buying a front mount, and honestly I might be putting this engine in a awd chassis that my friend has had just sitting there. I figure that if I am careful how I spend my money, I might be able to have this thing running good in a AWD car for only 1500-2000. total cost.

That being said, anyone know anything about these? ECLIPSE TURBO 4G63 FUEL PRESSURE REGULATOR GAUGE KIT: eBay Motors (item 250436319976 end time Sep-24-10 19:08:15 PDT) Think it would work fine?

I might do some shopping in the classifieds and see what I can find used as well.

 

[Chicken Patty]

Not to say that I wont spend the money, but so far this car has been an extreem budget build. I only have around 600 dollars in the car. I got the car for free(traded it for a car I planed on taking to junkyard. ). I know I will have to spend some money on it, but just not trying to go overboard. I still plan on buying a front mount, and honestly I might be putting this engine in a awd chassis that my friend has had just sitting there. I figure that if I am careful how I spend my money, I might be able to have this thing running good in a AWD car for only 1500-2000. total cost.

That being said, anyone know anything about these? ECLIPSE TURBO 4G63 FUEL PRESSURE REGULATOR GAUGE KIT: eBay Motors (item 250436319976 end time Sep-24-10 19:08:15 PDT) Think it would work fine?

I might do some shopping in the classifieds and see what I can find used as well.

Thing with eBay is you never know what you are buying. Lots have bad experiences, I personally have a golden tubular manifold on my car from eBay. That thing has been great for me, never gave me any sort of issues.

My buddy is running a eBay FPR by the way, working fine. However, I am not a fan of them. Just my .02 cents of course.

 

[Momar]

Do you know which one your buddy is running?

What manifold are you running btw?

 

[Chicken Patty]

Do you know which one your buddy is running?

What manifold are you running btw?

Don't know which one exactly, I can ask him though. As far as the manifold, I bought the last one and the guy never ordered more so I am unable to find it on ebay.

 

[JoshJosh]

i also have a 99 eclipse gs with the 420a motor and the other day my wife was driving it and she said that it just sputterd and shutd off. ever since then the car wont start. iv replaced the spark plugs and wires and fuel pump. the relay tested good i dont know what the problem is. when try to start the car it just acks like it wants to start the stops ### help