I need to fix this ASAP

[BlackMount]

Soo....I'm torn. My DSM is still having problems.....

when I got it, the ECU was bad...it would never rev past 3.5k in neutral, and would sometimes rev past that under a full 15 psi of boost...and it ran really rich and i got horrible gas mileage, and the car studdered and jerked and randomly died a lot.

So I got a new ECU which was a 1990 from what I was told. it was from this nice new place\guy down in aldamore AL\TN called DSM Warehouse.

The day I got my ECU, I was on my way home from a car show at a local auto tech school, when it started doing this thing where...say...I'm in 5th gear, going 45 mph @ 2,000 RPM... If I stay in that gear, it will accelerate as fast as i want it too, till 6,000 RPMS where it cuts me out completely. and the car will decelerate...I can press the gas all i want but it doesn't do a thing. this happens in every gear.

^^^^ That happend before I put the New ECU in and it still does it so that is out of the question. but doesn't jerk and shit.

so basically. if I accelerate past 2,000 rpm's i can keep accelerating as long as i don't let off till i hit 6,000 rpms and it cuts me completely, but if I let off i get a fuel\ignition cut or something that wont let me do anything until the engine drops back down to 2,000 rpm's. It also runs EXTREMELY rich. were talking so rich even if i baby it, a 1\2 tank of gas will only last me 50 miles. It also idles wired, the idle is steady, but it sounds like it is cammed. and idles at 600-750 (if i try adjusting it with the idle speed screw it doesn't change it at all)

So I assumed it was the the MAF sensor because if I unplug my MAF it wouldn't change a thing. so when I got a NEW MAF from a fellow member on here (which came off a running dsm fyi) i plugged it in, no difference.. I noticed if i slip the plug on the MAF slowly, about half way on, the engine will suddenly surge up like 100 RPM's and then go back to normal...

so now what? please help! i don't want sell the my DSM but I cant afford the gas and its my DD. and I can barely afford to fix it either so If I cant fix it I'm going to have to sell it.

EDIT: just some factors I thought I throw out there.... I've got a Blitz Turbo Timer with a A-B switch for cars with different ignition patterns or something like that, should i try switching that? I also have a CEL, but no one has a obd1 reader around here. I've called left and right. even Mitsu + Chrysler couldn't help me out.

EDIT: I unplugged both my MAF sensor and my 02 sensor at the same time, and the car didn't run the slightest bit different. WTF is going on.

 

[gofer]

http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.htmlI'm pretty sure the "brick wall" your car hits at WOT once it get to 6k is fuel cut... Your car is running SO rich that once it gets to that point the ECU kills the fuel going to the motor. The ECU watches the front o2 sensor to achieve a STOICH fuel trim, if the front o2 sensor dies the ECU is blind and it won't go into closed loop which would cause you to run really rich. Also, have you checked your fuel pressure? That fpr (fuel pressure regulator) on the end of your fuel rail might be shot.

Desperate times call for desperate measures and you can't find anyone to read your OBD1 CEL. Heres a "how-to" so you can read the code... http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.html

You have hardly anything modified on that DSM so fixing the problem isn't going to be so bad that you should just up and sell it. You just have to stop shotgun troubleshooting it and use the process of elimination.

 

[BlackMount]

http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.htmlI'm pretty sure the "brick wall" your car hits at WOT once it get to 6k is fuel cut... Your car is running SO rich that once it gets to that point the ECU kills the fuel going to the motor. The ECU watches the front o2 sensor to achieve a STOICH fuel trim, if the front o2 sensor dies the ECU is blind and it won't go into closed loop which would cause you to run really rich. Also, have you checked your fuel pressure? That fpr (fuel pressure regulator) on the end of your fuel rail might be shot.

Desperate times call for desperate measures and you can't find anyone to read your OBD1 CEL. Heres a "how-to" so you can read the code... http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.html

You have hardly anything modified on that DSM so fixing the problem isn't going to be so bad that you should just up and sell it. You just have to stop shotgun troubleshooting it and use the process of elimination.

Ok ok this makes more sense (the VFAQ)...... I was told just run the jumper wire, and it would make the CEL flash X amount of times as the Pulse..... and when I did it, it didn't do anything.

I like my DSM I really do, and getting rid of it would be a last resort, all thought I am attempting to trade for a rotary because that my Ideal tuner I hang around alot of rotarys (12A 13B 13Btt Renisis, 20B etc 1g 2g 3g rx3 etc) and that's what I want most, and from the start I've been playing on getting this dsm to where it was tradeable for something like a 13B 1st Gen or a 2nd Gen Turbo-II

I will try to run the codes again, and see what happens.

EDIT: would it be possible just to hook a light up as oppose to a buzzer? or is it not sending the signal that way?

 

[DroopYeyeS]

From what I'm reading, this thing is rich all thru the run right? Normally the thing that will cause this on a stock setup is the amount of air being seen by the ecu, leaky injectors, or bad sensor input to ecu,i.e.; o2, coolant temp. If the injectors are stock there aren't to many things that will cause it to go pig rich.have you tested all fuel related sensors?

 

[steve]

EDIT: would it be possible just to hook a light up as oppose to a buzzer? or is it not sending the signal that way?

Light bulbs draw too much current. You can use a 12v LED (or a regular LED with the right current limiting resistor) or the Piezo buzzer. Both of them won't draw more than 30mA or so.

There is no other wires to hook up, just connect the code reader to the pins (1 and 12) on the Diagnostic connector.

 

[BlackMount]

From what I'm reading, this thing is rich all thru the run right? Normally the thing that will cause this on a stock setup is the amount of air being seen by the ecu, leaky injectors, or bad sensor input to ecu,i.e.; o2, coolant temp. If the injectors are stock there aren't to many things that will cause it to go pig rich.have you tested all fuel related sensors?

The Fuel System is good as far as I know, 15k old walbro 255lph fuel pump and Fuel filter, I did a fuel pressure test when I got the car, I don't recall the PSI but it was more then good.

Light bulbs draw too much current. You can use a 12v LED (or a regular LED with the right current limiting resistor) or the Piezo buzzer. Both of them won't draw more than 30mA or so.


There is no other wires to hook up, just connect the code reader to the pins (1 and 12) on the Diagnostic connector.

so use something that draws less then 30MA? i will see about a radioshack, I just figured save my self some money and use light bulbs, I believe I have a LED or some other real small light bulb laying around....


I've been told different things now as far as checking the system

1: flip ignition on\off 3 times, and light should blink
2: connect jumper cables and light should blink
3: connect analog voltmeter or 12V buzzer to the 2 terminals.

Number 3 is the only one I haven't tried yet.....

 

[steve]

I've been told different things now as far as checking the system

1: flip ignition on\off 3 times, and light should blink
2: connect jumper cables and light should blink
3: connect analog voltmeter or 12V buzzer to the 2 terminals.

Number 3 is the only one I haven't tried yet.....

And #3 is the only correct answer for a 1G DSM.

You can use a LED but you have to use a dropping resistor so you don't burn it out. There are LED resistor calculators on the web for figuring out what value you need or just get a 12v one that already has it built in.

The piezo buzzers I sell are Radio Shack parts with microclips soldered on.

 

[gofer]

The Fuel System is good as far as I know, 15k old walbro 255lph fuel pump and Fuel filter, I did a fuel pressure test when I got the car, I don't recall the PSI but it was more then good.

You answered your own question right there in that post... a walbro 255 will outflow the stock fuel pressure regulator. Thats why your running rich, you need to get an aftermarket adjustable fuel pressure regulator (afpr) to fix the rich condition under boost.

I hate to say it Black Mount but I could have answered your question at 4:09pm yesterday (the time of my first post) had you updated your mod's list in your profile. I checked your profile and didn't see anything in there about a upgraded fuel pump, it looked stock! If I would have seen the walbro 255 fp as a modification but no afpr in there then I would have said something... so UPDATE YOUR PROFILE!

 

[Gasolinebaptism]

+297.
This is obvious, sometimes the stock FPR will hold up for awhile with a 255, then die. It just wasn't made to handle that much fuel, so the rail pressure skyrockets, pushing more fuel through injectors.

 

[BlackMount]

And #3 is the only correct answer for a 1G DSM.

You can use a LED but you have to use a dropping resistor so you don't burn it out. There are LED resistor calculators on the web for figuring out what value you need or just get a 12v one that already has it built in.

The piezo buzzers I sell are Radio Shack parts with microclips soldered on.

ok!

You answered your own question right there in that post... a walbro 255 will outflow the stock fuel pressure regulator. Thats why your running rich, you need to get an aftermarket adjustable fuel pressure regulator (afpr) to fix the rich condition under boost.

I hate to say it Black Mount but I could have answered your question at 4:09pm yesterday (the time of my first post) had you updated your mod's list in your profile. I checked your profile and didn't see anything in there about a upgraded fuel pump, it looked stock! If I would have seen the walbro 255 fp as a modification but no afpr in there then I would have said something... so UPDATE YOUR PROFILE!

Yes that makes me run richer, but not rich to the point I am talking about, friend of mine is running the exact same turbo set up as me (255 LPH Walbro w\ 450cc injectors and stock FPR) and he isn't running near as rich as I am, and he gets about normal Turbo DSM gas mileage. I already went through this on the forums before, the 255 is not that overpowering that i'd belch black smoke, and reak of gasoline at Idle \ driving range and get 100 miles to a full tank of gas like I am now.

It's gotta be something like my O2 sensor, I got a new O2 sensor for free from a friend, and the only reason I haven't installed it is because I don't have the right socket for it. It would make sense to be my O2 sensor because I was specifically told on this forum, running extremely rich for a long period of time like I was could destroy my O2 sensor, and I'm sure thats exactly what happend.

+297.
This is obvious, sometimes the stock FPR will hold up for awhile with a 255, then die. It just wasn't made to handle that much fuel, so the rail pressure skyrockets, pushing more fuel through injectors.

FPR is new because I replaced it along with a fuel rail, the fuel rail was used but much nicer then the one I was using, I also cleaned my injectors.

 

[Colt4G63 also]

Clearly you have all the answers then. Perhaps you can help me with my tune .

 

[BlackMount]

I do have most of the answer's, and Maybe I can help your tune, you just need to ask the questions.... but I still like a 2nd opinion, and that's why I ask, or incase there is something small, and simple that I overlook.

 

[jtalton626]

I am having almost exactly the same problem. My AF gauge shows that I am running uber-rich all the time, until I hit about 6 on the tach without boost, or with boost it won't make it past 4 grand. I am running a stock fuel pump, and a stock FPR. I'm about to invest in a 255 walbro and an AFPR. This SAME problem has followed me through two motors, two ECUS, two turbos, 2 new sets of injectors, fuel filters, a gas tank cleaning. The only four things left on the car that originally came on the car is the CAS, the FPR, the Fuel Pump, and the transmission. Everything else except for the shell is aftermarket, or salvaged, swapped, etc. I hope my two new purchases work well, otherwise I may be looking to sell mine too.

 

[loganflynn294]

Same problem here too. I'm running so rich that the plugs get wet with gas and the car dies. I've checked every sensor on the car, they're all fine. I'm pretty much stock except for afpr set to stock pressure, and maft that's pretty much zeroed out for stock settings. I think my problem is the ecu, the caps were leaking and the board had a lot of corrosion. I'll let you know if a new ecu fixes it.