Still chasing down a cutout problem
Ok...car is '89 2.5 with enforcer turbo, Daytona VNT intercooler, converted to 5 speed, 3 bar setup with boost at 20 pounds, accufab, FFV injectors, new plugs and somewhat new Magnecors, open downpipe, new (last summer) speed sensor, new cap and rotor, re-timed a hundred times...this is all my "relevant" mods. Car is set to 12 degrees and fuel is set to 55 PSI static pressure. I'd like to test my fuel at the rail, but my gauge leaks like crazy.
Basically, if I hammer the gas in 3rd, 4th or 5th gear, as soon as boost reaches close to 20 pounds, I experience what feels exactly like overboost shut down, which is fuel cut. Moparman and I have been through the cal over and over and made sure overboost was shut off.
When it's cold outside, my car takes FOREVER to come out of cold enrichment and my temp gauge usually stays pretty close to the coldest mark. I assumed that this was causing the problem since Moparman was having a similar problem and his van runs very cold. Also...this overboost thing don't occur 100% of the time and seemed to be absent when my car would warm up from sitting.
That all went out the window when it got over 60 degrees here and my car was at normal temps. I rolled into it in 3rd and experienced the fuel cut problem once again. I mashed it yesterday in 2nd and wound it out...boost was over 15 pounds and I roasted the tires...I experienced no problems.
Moparman also thinks that having less than a quarter tank of gas and having the fuel slosh to the back of the tank would cause this...but my problem isn't consistent with a certain fuel level.
When I switched to a 3 bar cal, I got my map sensor from ebay used for $30 and think that maybe it's not reading correctly. I also think that maybe the fact that I'm running a stock, original fuel pump could be the problem....but it seems that a fuel pump that's not flowing enough fuel will cause the car to sputter and lose power more than an abrupt overboost like situation.
This is just frustrating and every time I think I have it solved, it comes back.
Re: Still chasing down a cutout problem
Set your spark plug gap to around .022 to .025 if you haven't already.
Do you have an a/f gague to varify a lean or rich condition?
Any codes?
What are you using for knock detection?
Re: Still chasing down a cutout problem
Sounds like a HEP or that your 3bar sensor is really a 2bar sensor.
If your have a volt meter or power probe see what your 3bar signal voltage is with koeo. Since it is a 5v reference it should read around 2.5v if im not mistake. Someone correct me if i'm wrong. I'm just going by what my 2bar is.
Re: Still chasing down a cutout problem
Any codes?
Does your MAP sensor have its own dedicated line? Bypass the baro solenoid and see what happens.
Re: Still chasing down a cutout problem
plugs. change them. happened to me in the omni. went from brand new ngk plugs to good ol champions. running them for a year now. still no more cutout.
Re: Still chasing down a cutout problem
Quote:
Originally Posted by
turbovanman
Any codes?
Does your MAP sensor have its own dedicated line? Bypass the baro solenoid and see what happens.
I have the MAP bypassed now. I tried it with the baro connected and same deal. I even swapped a brand new vac hose to the MAP.
---------- Post added at 01:02 AM ---------- Previous post was at 01:00 AM ----------
Quote:
Originally Posted by
roachjuice
plugs. change them. happened to me in the omni. went from brand new ngk plugs to good ol champions. running them for a year now. still no more cutout.
I had AR51 Autolites in the before and same stuff. I don't think it's the plugs... I'm almost sure it's a fuel or fuel management issue.
---------- Post added at 01:05 AM ---------- Previous post was at 01:02 AM ----------
Quote:
Originally Posted by
86trbolancer
Sounds like a HEP or that your 3bar sensor is really a 2bar sensor.
If your have a volt meter or power probe see what your 3bar signal voltage is with koeo. Since it is a 5v reference it should read around 2.5v if im not mistake. Someone correct me if i'm wrong. I'm just going by what my 2bar is.
I'll try that.
I'm pretty sure it's a 3 bar sensor...I've hit well into the 20 PSI range numerous times with no problems...it's just that 9 times out of 10 if the car is in a gear higher than 2nd, the car will miss out near 20 pounds.
Re: Still chasing down a cutout problem
Sounds like spark blow out. I have never used ar51's, but they are a copper plug which isn't recommended for our cars. Get a set of autolite 63's for $10 and gap to .032, if you still get blow out, gap them smaller. You shouldn't have to go smaller than .025
Whether you had a 2 bar instead of a 3 bar would have no effect on a cutout condition if you have overboost removed from the calibration. It would have some timing issues with the map voltage vs computer setting but that doesn't cause cutout
Re: Still chasing down a cutout problem
Quote:
Originally Posted by
glhs727
Sounds like spark blow out. I have never used ar51's, but they are a copper plug which isn't recommended for our cars. Get a set of autolite 63's for $10 and gap to .032, if you still get blow out, gap them smaller. You shouldn't have to go smaller than .025
Whether you had a 2 bar instead of a 3 bar would have no effect on a cutout condition if you have overboost removed from the calibration. It would have some timing issues with the map voltage vs computer setting but that doesn't cause cutout
Cooper plugs not recommended? Seriously? Cooper plugs ARE recommended for turbo cars. That's all I run. Champion RN9YC. Never a problem out of the champions. Ngk's I've have problems with. I wouldn't run a platinum plug. Retains too much heat and is prone to detonation.
Re: Still chasing down a cutout problem
yes, I guess I had tht confused with the platinums.... thanks for clarifying that. Nonetheless, I beleive you have spark blow out. Change plugs and regap.... for $10 you're not out much even if it doesn't fix the issue.
Re: Still chasing down a cutout problem
Quote:
Originally Posted by
glhs727
yes, I guess I had tht confused with the platinums.... thanks for clarifying that. Nonetheless, I beleive you have spark blow out. Change plugs and regap.... for $10 you're not out much even if it doesn't fix the issue.
I was like Dam am I missing something here lol.
Re: Still chasing down a cutout problem
I still have a code 62, but I also have a code 45..WTF?
Re: Still chasing down a cutout problem
Quote:
Originally Posted by
86trbolancer
Sounds like a HEP or that your 3bar sensor is really a 2bar sensor.
If your have a volt meter or power probe see what your 3bar signal voltage is with koeo. Since it is a 5v reference it should read around 2.5v if im not mistake. Someone correct me if i'm wrong. I'm just going by what my 2bar is.
Not sure which way round you meant that, that if he measures 2.5V engine off, it should be a 2 bar, or that a 3 bar would read that. It's my understanding that a 1 bar reads 1/1x5V, a 2 bar reads 1/2x5v and a 3 bar 1/3x5V at 1 atm.... so he should be seeing 1.6-1.7ish
Re: Still chasing down a cutout problem
Dumb question....can an adjustable FPR lose it's setting after a while? I haven't touched my accufab for over a year...static base fuel pressure was stock last time I checked.
Re: Still chasing down a cutout problem
So we swapped out my 3 bar with his and it didn't change anything. Its that brick wall feeling that I get when I floor it with less and 1/4 tank in the van. I think its the 22 year old fuel pump showing its age.
Re: Still chasing down a cutout problem
How old is the filter? I can't get one to last more than about 18 months lately.
Re: Still chasing down a cutout problem
I chased down a similar problem after I turbo swapped my van, I still had the 20 something year old TBI pump in there and ended up putting in a walbro. After that I noticed that if I don't keep it above half a tank it cuts out when I get on it. I tried a filter before the pump and it didn't change anything.
Re: Still chasing down a cutout problem
Before I went to George's place for him to take a ride, disconnected the battery and checked the codes.....none except 62. We went for a ride and experienced the cutout problem, swapped MAP sensors and still had the problem, etc... Came back home and checked codes again...code 45 shows up. ???WTF??? George said he's raised every parameter related to overboost shutdown to 25 PSI. I don't get it. I agree that I need a pump tho. My filter was changed last year when it started getting cold out.
Re: Still chasing down a cutout problem
Quote:
Originally Posted by
3Bar_Mopar
Before I went to George's place for him to take a ride, disconnected the battery and checked the codes.....none except 62. We went for a ride and experienced the cutout problem, swapped MAP sensors and still had the problem, etc... Came back home and checked codes again...code 45 shows up. ???WTF??? George said he's raised every parameter related to overboost shutdown to 25 PSI. I don't get it. I agree that I need a pump tho. My filter was changed last year when it started getting cold out.
just set it all to FF(turn it off). I think the GM sensor is not completely linear and could be off 1 or 3 psi so going over 20 could be translated as 25psi.
Re: Still chasing down a cutout problem
I'll redo it on the newest code base and set it all to max just to make sure that isn't it.
Re: Still chasing down a cutout problem
any updates on this? I'm interested because I seem to be chasing the EXACT same problem in my Daytona, only it happens dead on @ 14psi. Not in 1st or 2nd gear, but 3rd-5th. I didn't have this problem when I put the car away in November, but now it's appeared. I've changed the plugs, and shortened the gap to .027, and my fuel is good. I don't think it's a cal issue, because I haven't changed anything in the cal. Today I came up with a theory as I was driving around. I noticed that since I brought the car out, the stock temp gauge doesn't even get past the C mark. I had assumed that it just had something to do with the cold temps we've had that I've been driving in. I figured the car just wasn't warming up. BUT I have decent heat. That leads me to believe that either the CTS, or the gauge itself is faulty. Today, I installed an AutoMeter water temp gauge, and verified that the car is in fact getting up to temp. In fact, the car gets up to temp (180F) pretty quickly. Now for the interesting part. The fan doesn't turn on when it's supposed to! This leads me to believe that it's the CTS itself that's faulty. I believe that if it were the wiring that was faulty, the CEL would come on, and put the car in limp mode, just like it does when you unplug it to adjust the timing. Now for my theory; the faulty CTS is telling the LM that the car is ALWAYS cold, and I'm pretty sure in my cal, if I remember correctly, there's a boost limit set at 14psi when the car is cold. This doesn't appear in first or second gear because I personally don't have enough traction to let the car get to 14psi before I'm ready to shift. I'm going to change the CTS tomorrow, if advance has one in stock, and test my theory. It's worth a shot!