I might be out of fuel

[Caliber308]

 

 

Yeah, I set the base at 0 and worked with just the 3 knobs. she still cuts out. What SQR said above makes sense too. Either way it's fuel. I am either not getting enough pressure at the TB or there is a restriction or the injectors suck. Either way, I am getting close. Now I just have to narrow it down. It bucks less when i am lean which is another indicator that SQR is right, that I am not getting the fuel I need so the ecu is cutting it out. I will get a base line pressure at the TB. If the pressure is good then it's a flow problem in which case it could be the injectors or a clog in the system somewhere.

 

I was reading the great maft thread and notice someone had said they had the exact same problem. They switched to to 950's and never looked back, the problem was taken care of. So it makes sense. I will get it figured out. Thanks for all the help.

 

L

 

Like I have said in other posts, and Starquestrescue posted in this thread. You need to read your fuel pressure on full boost. First you need to know your idle FP. Then add that number to your boost psi. So, if your Idle FP is 40 and your boosting to 15 psi. Your total FP at full boost needs to be 55. Taping a GOOD Fuel Pressure Gauge to the windshield will work. Don't skimp on the FP gauge, use a really good one. I use a Stewart/Warner Performance Gauge that I purchased from a Marine shop in California. I can hear it now: "Cal, why did you buy a FP gauge from a Marine shop"? It's simple. If the SW Performance FP gauge works in boats which bounce around (up and down, side to side) and the needle doesn't move, it gives you a super accurate reading...So,why not use it? Sure it costs more, but the accuracy is undisputable. Reading your FP this way will tell you real fast if your running out of fuel at 15 psi boost. If you are, Then it is just a matter of chasing down why you are running short on fuel delivery (Injectors,Fuel Pump, Fuel filters, Fuel Pressure Regulator and/or Wiring).

 

 

Bill

Edited March 21, 2012 by Caliber308

[Indiana]

I'd try a different MAS. Your issue might be the ECU not able to use what it determines as a screwy signal whether it comes from that MAFT or not and when it does it can cause something like that when it switches to using only the tach signal.

[Lance_S]

Thanks Indy. I am going to pick up a new, in car, fuel pressure gauge (electronic, not mech.) and probably pull the injectors and run cleaner through them to start out with. The MAS certainly could be the issue as well, I have heard some having problems with the 3 inch mas. I am going to start with fuel since I need to know where it's at anyway and if that doesn't solve it I will move on to the mas.

[gottraction]

what ecu is in the car?

[Lance_S]

88/89 transferred to an 87 box

[Caliber308]

Thanks Indy. I am going to pick up a new, in car, fuel pressure gauge (electronic, not mech.) and probably pull the injectors and run cleaner through them to start out with. The MAS certainly could be the issue as well, I have heard some having problems with the 3 inch mas. I am going to start with fuel since I need to know where it's at anyway and if that doesn't solve it I will move on to the mas.

 

Thanks StarquestRescue, Thanks Indy............ Screw you Cal Why am I wasting my time trying to help you? You haven't taken any of my advice so far. P.S. You don't need a in car electric Fuel Pressure Gauge. But, if you want to spend double or triple of what it costs for a electronic vs. a mechanical one.....Go for it. I suggested with years of knowledge on my MAF-T set up how to go about checking or upgrading things. I really don't mind helping members out. But, when a member tells you how to go about doing something that has ran a Maf-Translator successfully for 6 years and your still not listening......... I'm done spending my time trying helping you.

 

Bill

Edited March 21, 2012 by Caliber308

[Lance_S]

 

Like I have said in other posts, and Starquestrescue posted in this thread. You need to read your fuel pressure on full boost. First you need to know your idle FP. Then add that number to your boost psi. So, if your Idle FP is 40 and your boosting to 15 psi. Your total FP at full boost needs to be 55. Taping a GOOD Fuel Pressure Gauge to the windshield will work. Don't skimp on the FP gauge, use a really good one. I use a Stewart/Warner Performance Gauge that I purchased from a Marine shop in California. I can hear it now: "Cal, why did you buy a FP gauge from a Marine shop"? It's simple. If the SW Performance FP gauge works in boats which bounce around (up and down, side to side) and the needle doesn't move, it gives you a super accurate reading...So,why not use it? Sure it costs more, but the accuracy is undisputable. Reading your FP this way will tell you real fast if your running out of fuel at 15 psi boost. If you are, Then it is just a matter of chasing down why you are running short on fuel delivery (Injectors,Fuel Pump, Fuel filters, Fuel Pressure Regulator and/or Wiring).

 

 

Bill

 

 

Bill,

 

Wow, O.K. Mister sensitive. Listen. I do my best to thank every person on EVERY single post. I missed thanking you. That wasn't my intention and I am sorry about that. But your acting like a 12 year old when someone forgets to thank you and it is ridiculous. Whether you think I need a electric fuel pressure gauge or a mechanical one is not the point. I am taking your advice. i know what my idle FP is. I have a gauge on the TB. What I don't have is a hose. I can go pick one up but just realized that the face on the gauge has two small screws on it that hold the face in place. One of the screw came loose so I need to replace it. I can replace it with another gauge, at the TB, but every time there is a problem with these cars on higher than stock boost the first thing that someone says it "Get a pressure gauge and tape it to your windshield". Well easier said than done. The hood closes tight, so you can run it half cracked, which I won't do or you can put a ton of washers under the mounts, which seems goofy to me, or you can pull the hood off all together, which I don't want to do.

 

The next time i have a problem, which will be in the future some time. Someone is going to say "strap a FP gauge to your windshield". Seems a little redundant to me. I have decided that the best way to avoid hearing that again is to buy one and stick it in the frickin car permanently. I don't care whether you think that is a great idea or not. It's a gauge for goodness sakes. The goal is to find out what fuel pressure is at boost right? Well, I think that might do it.

 

If you are so insecure that you need public praise for every suggestion and your retaliation is to let me know that you are done with me for not thanking you and assuming that because I didn't thank you, I was saying "Screw you Cal" instead of maybe assuming that I had just missed it? You have some growing up to do.

 

You told me to set the maft straight up, I did that. You told me to know where my base fuel pressure was, I got that. You told me to buy a hose and run it to the windshield, instead, because I need to replace my gauge anyway, I thought it might be nice to always know what my fuel pressure gauge is, you freak out on me. Stop acting like a baby, your not 12 anymore and neither am I.

 

Just like you suggested, I am tracking down my fuel delivery problem, if that ends up to be the cause. In the process, other good suggestions have come along from other members, like....Cleaning the injectors, checking the filters, etc. I will follow their advice too. I will continue to follow everyone's suggestions until I figure it out. But I would appreciate the benefit of the doubt in the future from you and not some rant.

[StarquestRescue]

Thanks Bill,

 

Yeah, the FSM calls for .039 to .044 if I am not mistaken. I have mine right at .040 but I might be blowing them out around 15 psi. I did correct the MAFT settings today and still have the same problem. Gonna pull the plugs and drop the gap to around .032 to .034 and see if I can correct it.

 

Now I need to find out what plugs people are running with higher boost levels. I know that some are running colder plugs with higher boost but I don't remember what the rule of thumb is for how much boost calls for a step down in plug temp and if the NGK's are the ones to stick with or not.

 

Thanks,

 

L

[Caliber308]

Lance,

I did come on a little strong and I apoligize. But, your making this way harder than it is. You can hook up a hose off the Throttle body and leave your hood in the safety hatch position to run a hose. It will not fly up and smash into your windshield. Believe me, I've done it. Look, your Maf-T set up works fine throughout the RPM range, Just not at 15 psi boost. So, that tells me either your running out of fuel at 15 psi boost (Check your Fuel Pressure on full boost) or your Spark Plugs are not gaped properly, the proper ones to run at higher than stock boost with your modifications, or they are JUNK. When I went to higher than stock boost here's what I did. Tried these four Spark Plugs:

 

NGK BPR 6

NGK BPR 7

NGK BPR 8

NGK BUR 7

 

At one point or the other, they all worked fine. But modifications were the determining factor, as I was doing them while trying different Spark Plugs and gaps. Maybe you are at that point in your mods? Hell, try them all at different gaps. You will find the correct Spark Plug and gap sooner or later. But first, CHECK YOUR FUEL PRESSURE AT FULL BOOST (15 psi)

 

Good Luck,

Bill

Edited March 24, 2012 by Caliber308

[boostdquest89]

http://i1050.photobucket.com/albums/s410/pratishtha1/imagesCA0WGRVC.jpg

http://i1150.photobucket.com/albums/o615/KatanaPop/LOL.jpg

[TainterRacing]

Lance is this the same thing it was doing when I road in the car?

 

If it is thats not the spark plugs.

Edited March 24, 2012 by TainterRacing

[Tim_C.]

A lot of questions are answered when you get your in-car gauge working to read FP under load / at boost. Could easily be a clogged filter, or injectors need professionally cleaned, MAF-T not working right, etc....

 

I wonder too if your distributor is advancing properly. You definitely need to check base timing, and timing at full advance, and see when it gets to full advance. You should see 28 -34 degrees or so at full advance with a stock distributor.It should get there by 3300RPM. You might find your mechanical advance is not doing anything, or going full too soon, etc...

[Lance_S]

Lance is this the same thing it was doing when I road in the car?

 

If it is thats not the spark plugs.

 

 

Matt,

 

Yup, still working on the stumble. No, it's not the plugs. I dropped the gap to .032 and no change.

 

L

[Lance_S]

A lot of questions are answered when you get your in-car gauge working to read FP under load / at boost. Could easily be a clogged filter, or injectors need professionally cleaned, MAF-T not working right, etc....

 

I wonder too if your distributor is advancing properly. You definitely need to check base timing, and timing at full advance, and see when it gets to full advance. You should see 28 -34 degrees or so at full advance with a stock distributor.It should get there by 3300RPM. You might find your mechanical advance is not doing anything, or going full too soon, etc...

 

 

Tim,

 

Yeah, I will know alot more next week. I rebuilt the dizzy a while back. It's snaps back great. New cap, rotor, wires, plugs, etc. I have checked the base timing twice. I will wind it up tomorrow and double check it at advance but I know it's right at 10 degree right now at idle. I pulled the injectors today. They are trilogys and have 650 and 950 etched on the injectors. I sucked on them, they don't leak. They are in the proper position. I then pulled the wiring off the clips and rewired them, just to make sure they were correct for the primary and secondary and also positive and negative. All is correct and it's still kicking on me.

 

At WOT I am at 10 on the AFR. I can't imagine that I am out of fuel at full boost (currently 15 lbs). If I were running out of fuel, it would be running lean. And it's definitely fuel. It will be at 10 then it will fuel cut, go lean for a split second, then back to 10 under boost. I think SQR is right when he mentioned that the ECU might be seeing full duty cycle and might be pulling the fuel from me. I am going to try and make a vid and post it so you can see what it's doing. In the mean time, I am working on picking up a new pressure gauge and getting it installed.

 

It might also be a bad mas or maft like you mentioned. Getting closer. Like I said, pulled then injectors today, shot loads of brake cleaner through them, the spray looks great. Redid the wiring and everything looks great. Still acts the same way though. I will know more tomorrow. Gonna check the pump and the filters.

 

Thanks for everything guys, I appreciate the help. You too Cal!!!

 

Lance

[Indiana]

When the MAS sends a crappy signal to that translator and it sends that to the ECU and its out of range the ECU will disregard that signal as being screwy and switch to the tach signal. Your translator at that point becomes useless and the ECU goes back to its own fuel map where it thinks the injectors are OEM and the boost is stock. Get a different MAS. If that MAS is good then you have a fuel delivery issue. Its not ignition, its not TPS, its likely not your translator, its not the timing, if the ignition isn't advancing it will still run but it won't have any power and it likely won't make boost. If it doesn't retard boost then your knock sensor is still there. Maybe the knock sensor has a wire broken off and its making intermittent contact as it vibrates. You can see these inputs while driving if you put a volt meter to the pin outs on the ECU and look at the ECI checker chart in the service manual to know which inputs to check. You can check the air flow sensor input which is that translator signal and watch what it does. It gives a spec in the manual from idle to 3000 rpms as 2.2-3.2v. The input to that is max 5v. If you drive and all of a sudden you see the signal jump the ECU will ignore that and switch to the tach signal and that's likely when you seem to run out of fuel and you would because you're a high boost with a non stock turbo then the knock sensor might be going off right after this happens. I think you're wasting your timing looking at filters, look at see what the ECU gets as inputs and if they are in proper range and if they are then look for a filter problem. Its simpe to do if you have the ECI checker and its adapter harnesses but you can do it with just a volt meter. I'd use the volt meter and let someone else drive. You can look at your intake air temp sensor signal which I doubt you even have since it was in the MAF so already you are at a disadvantage.

[Lance_S]

Thanks for the new idea Indy. I will give it a shot. The only reason I don't think it's a bad knock sensor is because if I drop the boost to 12 l s all my symptoms go away. It only happens when I bump up the boost. If it were a broken wire, the boost level wouldn't matter. Edited March 25, 2012 by Lance_S

[NudeLobster]

I typed out a huge reply in detail and it got deleted. :mad:

 

so I'm just going to say, I have the same buck/miss at the same 16-17psi. I too will run mid-high 10 AFRs at WOT, it will buck/cut/miss/whatever for an split second, the WB gauge will show 18+ lean for a split second after, and then back to 10's AFR. 15psi boosts fine.

 

1G MAS

89 ECU

AEM truboost EBC

stock FPR

LSP 650/950 injectors

bosch 044 pump

BUR7ES11 plugs gapped to .032

42ish base fuel pressure

10 BTDC base timing

rebuilt dizzy with new vac advance

 

no FP reading at WOT...gauge is on TB. I know ya'll will tell me the same thing: tape a gauge to the windshield but the car isn't even running right now and when it is in a few weeks it will be on MAF-T gen 2 SAFC

 

comparing our set ups, I'm leaning toward injectors? Even if so, how are we supose to use OEM injectors when we need higher output? with all my porting and higher boost this year, I'm sure I'll need to bump injector size after I get me an ARRFPR. until then it will stay at around 15-17 psi, but by summer I'd like to be at 20-22psi

 

I noticed it went a way for a while when the weather turned cool in the fall. Then, it came back after about a month, though much it happened much less compared to the hot,humid summer months. I was convinced for a while that it was the stock MAF just giving whack signals from the higher-than-stock boost like SQR's data logging graphs showed (frequency going hay wire with higher boost and aftermarket intake pipe) but now that whole theory goes down the drain since lance has a GM MAF.

 

-Justin

[Lance_S]

I typed out a huge reply in detail and it got deleted. :mad:

 

so I'm just going to say, I have the same buck/miss at the same 16-17psi. I too will run mid-high 10 AFRs at WOT, it will buck/cut/miss/whatever for an split second, the WB gauge will show 18+ lean for a split second after, and then back to 10's AFR. 15psi boosts fine.

 

1G MAS

89 ECU

AEM truboost EBC

stock FPR

LSP 650/950 injectors

bosch 044 pump

BUR7ES11 plugs gapped to .032

42ish base fuel pressure

10 BTDC base timing

rebuilt dizzy with new vac advance

 

no FP reading at WOT...gauge is on TB. I know ya'll will tell me the same thing: tape a gauge to the windshield but the car isn't even running right now and when it is in a few weeks it will be on MAF-T gen 2 SAFC

 

comparing our set ups, I'm leaning toward injectors? Even if so, how are we supose to use OEM injectors when we need higher output? with all my porting and higher boost this year, I'm sure I'll need to bump injector size after I get me an ARRFPR. until then it will stay at around 15-17 psi, but by summer I'd like to be at 20-22psi

 

I noticed it went a way for a while when the weather turned cool in the fall. Then, it came back after about a month, though much it happened much less compared to the hot,humid summer months. I was convinced for a while that it was the stock MAF just giving whack signals from the higher-than-stock boost like SQR's data logging graphs showed (frequency going hay wire with higher boost and aftermarket intake pipe) but now that whole theory goes down the drain since lance has a GM MAF.

 

-Justin

 

 

Justin,

 

Very interesting. Sounds like the exact same problem. I have stated this before, but there was a guy on the great maft thread that said he had the same problem we did. When he changed out to bigger injectors, the problem went away. Interesting.

 

The reason your symptoms went away when it was colder was because you were running leaner. If I lean my fuel map out, it won't buck. but of course, it will melt the motor. So i can't do that. But that is most likely why it didn't do it when it was colder. I am still going to try and get a vid up, just so people can see and hear what it's doing. But it sounds like the same thing. I too, have a ported head and turbo. I buck at 15 to 16. I will try and run a vid of it at 12 to 13, then 15 to 16 to show the diff.

 

Getting closer to figuring it out anyway. I thought maybe I needed a larger fuel pump, but you already have one and your bucking too. We will get it figured out. Thanks for the input, helps to know someone else is dealing with the same thing.

 

L

[TainterRacing]

Maybe Ignitor..... Have you tryed that??

[StarquestRescue]

You guys are just stumbling around in the dark making wild tail guess's. You have to know what is going on and that means gauges and or data logging.

 

This is $129 shipped on ebay. http://www.innovatem...ducts/ssi_4.php Than you need a usb adapter and of course a lap top. With one of these you will Know what your injector duty cycle is. You will Know what your air flow is. plus 2 other channels. Fuel pressure and boost require additional sensors.

 

Than you get to look at fancy charts and grafts like this.

 

New fuel pump pressure overlay-ed over old pump. That is a 10 psi drop off. I was tuning for the drop off, thats why the afr about the same.

 

http://i237.photobucket.com/albums/ff45/StarquestRescue/Data%20logs/WalboGS392fuelpump.jpg

 

Fuel cut from trying to run to close to the top of the fuel map. Had i been a little leaner i might have gotten away with it. That is 1/2 second from the time the injector shut off till they came back on. The dark line is the injector duty cycle.

 

http://i237.photobucket.com/albums/ff45/StarquestRescue/Data%20logs/E85fuelcut.jpg

 

Or for you 1g mas guys here is one in trouble or over run. This is the stuff that blows motors. The airflow is the jagged trace that trends downward for no reason. And the injectors tracked that. As apposed to shutting of clean like in the example above. The injector duty cycle is the dark and yellow lines at the top.

 

http://i237.photobucket.com/albums/ff45/StarquestRescue/Data%20logs/Fuelcutdifferentview.jpg

Edited March 25, 2012 by StarquestRescue

[Lance_S]

I am not stumbling in the dark, I just can't do everything all at once. This is a learning process that doesn't happen overnight. There have been quite a few things that have been ruled out and things that were very good to have been checked and checked again. Things like timing and cam position, tps/isc, plugs and the their gap, igniters, ecu, dizzy advance, plugs, wires, rotor, cap, etc. I have learned quite a bit through this process. This is the way it goes. I have had the car less than a year and have rebuilt most of it.

 

I would love to buy the system you have and I might be able to at some point. But there are alot of guys who have had these cars for a decade or so and expect that those that have only had them a year are suppose to have this all figured out. It just takes time....and money, which I am extremely short on right now.

 

Maybe this summer, when I have a job, I can grab one of those data loggers. Looks great. In the mean time, my next step is making sure I have pressure at boost. Once i am sure I am safe on the fuel, I can move on to the next step. I will get it figured out, just takes a bit of time. And I can only wrench on the weekends.

[Lance_S]

Maybe Ignitor..... Have you tryed that??

 

 

Yeah, swapped it out. Not the igniter.

[Caliber308]

Lance,

 

I have read your responses for help in this post, this is what I saw a lot of: " The Wideband is reading 10.0 afr at WOT at 15 psi boost" Well, that is way too rich. I have experienced this also on my car. My set up spit and spuddered at a 10.0 afr Wideband reading at 15 to 20 psi boost, Why? Too much fuel.Try dialing back the fuel on the MAF-T at WOT to 13.0, 14.0 or less. Too much fuel is just as bad as not enough. After all, you won't go lean until a AFR reading of 16.00. Going lean and then rich with spuddering tells me that either your: Fuel Pump, Fuel Injectors, Fuel Filters, Fuel Pressure Regulator, Injector Clips,Spark Plugs,Spark Plug wires, ECU or Wiring are/or suspect. If the car starts up and idles properly you can eliminate the Igniter and Timing. But, you might want to test your Vacuum Advance and Detonation Sensor. Example: Right after my Engine Rebuild, I took it out on the road for the first time. Ran it up to 5500 rpms, it had a hesitation and a hard hit at appox. 3,000 rpms. Solution....A new Vacuum Advance. Sometimes, it's the little things that matter to make your car run fine. But first, I'd dial back the fuel to a 13.0 AFR reading on your Wideband at WOT.

 

Good Luck,

Bill

Edited March 28, 2012 by Caliber308

[Lance_S]

Lance,

 

I have read your responses for help in this post, this is what I saw a lot of: " The Wideband is reading 10.0 afr at WOT at 15 psi boost" Well, that is way too rich. I have experienced this also on my car. My set up spit and spuddered at a10.0 afr Wideband reading at 15 to 20 psi boost, Why? Too much fuel.Try dialing back the fuel on the MAF-T at WOT to 11.0 or less. Too much fuel is just as bad as not enough.

 

Bill

 

Cal,

 

Your absolutely right, ten is pig rich, I can smell the fuel. I backed it out to 12 to 13 and it won't sputter, but 13 is a bit lean. I have read quite a bit and the general consensus is anything under 12 is safe. 11.5 to 11.8 is preferable. Of course, opinions differ a little over decimals but the general idea is 12 or under. You can confirm that, let me know what your running. I haven't had a chance to get back to work on the car since the weekend so no new update yet. I have a week off next week so I will have fuel pressure numbers under boost by then and have some time to dial in the afr.

 

But you are right about too much fuel being a problem. Before I put the new head on I did have it leaned out to 12 or so and it didn't sputter but when I turned it up closer to 15 lbs it still bucked on me. At 12 or 13 lbs it didn't. It just interesting that it seems to be a air pressure threshold that once I am over I run into this. Of course that can also relate back to the fuel map or the mas.

 

But I will pull the fuel out and double check it this weekend for sure.

 

Thanks,

 

Lance

[Indiana]

Set your timing back to 8 if you want to pull some heat out. 12 isn't lean, neither is 13. Ignition timing is where the heat comes from. Its how long, in degrees, that's allowed to burn. Initial compression ratio, boost psi and intake air temperature combine with the air/fuel ratio and total timing and there's your recipe for the heat that will be produced. Edited March 28, 2012 by Indiana