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tadmichael22
02-03-2004, 04:58 PM
Okay I have tried just about eveything I possibly could and still no go. Okay I have a 93 with 42# injectors, 76mm maf, adj. fuel reg. With the mafs unplugged the car will run. When the maf is connected it wont. It fires real quick goes up to approx. 3000 rpm and instantly stalls. I try to give it gas and that doesnt phase it at all. The last time I tried to start it it kinda sounded like it backfired. I changed my maf sensor with 2 different ones thinking it was the prob but it wasnt. I have also checked for any vac. leaks but I have none. I have had this prob now for about a month and am ready to jump off a bridge!! I checked for codes and the scanner I have said all clear.. I just checked for grounds thinking that could be the prob. but didnt find any bad ones. I saw in another post there is a ground on the back of the left head. Is that the bolt to the fuel reg? Please if anyone can help me please let me know!! P.S. sorry about the long post.

ThunderDave
02-03-2004, 06:27 PM
I'm not sure, but from some of the posts I've read, if it will run without the maf hooked up and not run with it hooked up, the problem could be the maf. Itmay be in the maf wiring. Sometimes it gets pulled on and can cause a bad connection in a circuit. Doug Franklin had one that was doing that, you may want to check with him about it.

Hope someone else will give you some ideas. Good luck!

David

Brandon
02-03-2004, 06:53 PM
The problem definitely lies within the MAFS itself or the plug-in connector. My car had the same problem and I switched the MAFS and it ran like a dream. If you tried a few different ones, I'd look at the wiring and the connector.

tadmichael22
02-03-2004, 06:54 PM
well when I called C&L about it to see if they had any ideas the told me to do a continuety check with the black wire and I believe it was the red wire I had to check for 12 volts and both of them were fine. So thats why I just assume its okay.

tadmichael22
02-03-2004, 06:58 PM
the really wierd thing is that when I had the maf connected it did run 1 time. I let it idle for about 30 minutes or so and then shut it off to check over everything. When I tried to fire it back up it went back to the same stuff. Thats whats really wierd is that it did indeed run with it connected 1 time.

Brandon
02-03-2004, 07:20 PM
Mine ran too for a couple of days with the bad MAFS. Then it went back to its old tricks. I have no explanation for it. Maybe try wiggling the MAFS connection when someone else is trying to fire the car. I don't really know what else to try.

ThunderDave
02-03-2004, 07:53 PM
Thanks Brandon, I didn't want to send him down the wrong trail.


David

forcefed95sc
02-03-2004, 09:50 PM
There is a ground on the bolt that holds the fuel regulator to the engine. It has an orange wire on it. The other two are on the motor mount brackets. One on each side, on the back bolt.
But I would have to agree, check the wiring on the MAF.

J57ltr
02-03-2004, 09:56 PM
Originally posted by tadmichael22
well when I called C&L about it to see if they had any ideas the told me to do a continuety check with the black wire and I believe it was the red wire I had to check for 12 volts and both of them were fine. So thats why I just assume its okay.

How EXACTLY did you do this test?

Jeff

Brandon
02-03-2004, 10:00 PM
Originally posted by forcefed95sc
There is a ground on the bolt that holds the fuel regulator to the engine. It has an orange wire on it. The other two are on the motor mount brackets. One on each side, on the back bolt.
But I would have to agree, check the wiring on the MAF.

The '93s don't have the ground wire that connects to the fuel pressure regulator. Don't even bother looking for it. The later cars (maybe '91 and up) were grounded through the 02 sensors....hence 4 wire 02 sensors, rather than the earlier 3 wire 02 sensors.

tadmichael22
02-04-2004, 08:16 AM
Okay you guys really had me wondering if I missed a ground or not. Okay Jeff what I did was made sure that the black wire grounded out and it did. Whith the key on I checked the red wire and it came up 11.92 volts w/key on.

tadmichael22
02-04-2004, 08:17 AM
Also just wanted to thank you guys for the responses I need all the help I can get right now!!!
Tad

sail7seas
02-04-2004, 08:54 AM
>Okay I have a 93 with 42# injectors, 76mm maf, adj. fuel reg.<

Have you disconnected the battery to reset the computer?
The car came/designed with 30# injectors, could it be flooding out?
Pulled any codes off a reader, Murphy's law?

ahh the a SC affair continues. All the best, with some luck thrown in.
Chris

tadmichael22
02-04-2004, 05:23 PM
No it isnt flooding out at all. I have pulled the plugs and checked them and they seemed fine.

tadmichael22
02-04-2004, 05:26 PM
Oh sorry I forgot the rest. I did try to pull codes and all I got was a 111 which is all clear. Also yes I did disconnect the battery.
Tad

seawalkersee
02-04-2004, 06:43 PM
Okay, what C&L told you was correct but I think you are supposed to have batt. voltage at the connector (I will check and get back with you). I think there is a short inside your MAF sensor circuit. The reason the car runs without it plugged in is because it goes into FMEM (Failure Mode Effects Management). When it is not plugged in the computer replaces what it is supposed to see from the sensor with a generic number that it gets from the MAP sensor TB snensor and others. I think you should pin out the sensor to the processor and clean it. If you have one there replace the electronics and see how it runs. Also sounds like your getting oil into your crank sensor or sometihing. I have not had any MAFs cause this problem.

Brandon
02-04-2004, 07:34 PM
What exactly do your plugs look like? After putting new plugs in and trying to fire it maybe 1/2 dozen times my plugs were black.....very, very rich. Are you sure the MAFS that you tried worked? Try another one from a running car.

J57ltr
02-04-2004, 08:04 PM
The MAf should have battery voltage on it. If you had the engine running at the time then that (11.91) is way too low. You should have about a couple of tenths of a volt drop between the battery and the MAF sensor. You should also check the voltage output of the sensor and make sure it's not putting out excess. The voltage varies between 0-4.??V.

Since you can't check it running (since the engine dies) you could hook up your DMM and blow across the filiment and see if there is a change. (maybe a leaf blower) The connections for the MAF output signal are C&D (A&B are the supply)

Are you sure you have the correct sample tube? It should be Orange.

Jeff

super red91
02-04-2004, 08:40 PM
I also think that the problem is a bad maf sensor. Find one that you know works, and use that one on your car.

J57ltr
02-04-2004, 10:46 PM
Someone else had the same problem you are having and the fuel pressure was like 19 psi. He had an adjustable regulator though.

Jeff

tadmichael22
02-04-2004, 11:38 PM
I would love to try using someone elses but I dont know anyone who has one. Just hard to believe that my stock one went bad and then 2 auto zone ones were bad also. Especially when the car ran fine before I took it apart.
I have a purple sampling tube which c&l said was the right one for a 93.
The plugs were definately carboned up a little but not to extremes.
With just the koeo what kind or reading should I be getting from the red wire going to maf sensor?
Tad

J57ltr
02-05-2004, 12:44 AM
Here is a chart I had saved.

According to Dr. Fred:

C & L MAF - Sample Tube to Injector Guide

73 MM_ _ _ _ _ _ _ _ SC Model Years_ _ _ _ _ _ _ _ _ 76 MM
_ _ _ _
Color_ _ _ _ _ _89-93_ _ _ _ _ _ _ 94-95_ _ _ _ _ _ _ _ Color

silver*_ _ _ _ _ 30_ _ _ _ _ _ _ _ 36/38_ _ _ _ _ _ _ yellow
blue_ _ _ _ _ _ 36/38_ _ _ _ _ _ _ _ 42_ _ _ _ _ _ _ _ _orange
red_ _ _ _ _ _ _ _ 42_ _ _ _ _ _ _ _ 50_ _ _ _ _ _ _ _ _ purple
green_ _ _ _ _ _ 50_ _ _ _ _ _ _ _ xx_ _ _ _ _ _ _ _ _ green

* We call it a "silver" one and C & L calls it a "clear" one.


Now there is still the fuel pressure issue have you checked it? You don't KNOW unless you check. And knowing is half the battle....

Jeff

super red91
02-05-2004, 12:51 PM
I sold tad the 76mm C&L maf that he is using now. It has the correct sampling tube for 42# injectors, I used this maf on my car and it worked fine. I feel really bad that all this is happening to you and wish i knew more to help.

tadmichael22
02-05-2004, 06:55 PM
I have a fuel pressure guage on the rail. Its running @40psi.

David Neibert
02-05-2004, 07:08 PM
Purple is correct.

David

Superloop
02-05-2004, 07:15 PM
When it is not plugged in the computer replaces what it is supposed to see from the sensor with a generic number that it gets from the MAP sensor
These cars don't have a MAP sensor they have a BAP sensor;
sorry, just had to let that out:D

Have u discovered what the problem is, tadmichael22?

seawalkersee
02-05-2004, 09:59 PM
Sorry bout that. You sir are correct. And for anyone who needs to know the difference a MAP or Manifold Pressure Sensor has a hose that runs to the Manifold. Since ours has a SC on it, the pressure would damage the electronics. Hence BAP Barometric Pressure Sensor. Same principal totally different numbers.

tadmichael22
02-06-2004, 08:39 AM
nope still same thing I dunno what else to check?????????
Tad

seawalkersee
02-06-2004, 10:38 AM
I missed it the first time. What is it with people and Auto Zone? If you are going to buy electronic parts that are specific to a car...they need to be purchased from a dealer or an aftermarket up grade (likc C&L or Pro M in this case). Your best bet is to check the sensor values. If it runs fine with it unplugged and you get no codes when it is plugged in. Im thinkin the MAF is the problem. However you still have low voltage to it which could also present a problem. Also do not rule out the possibility of two problem components that are not working with each other.

seawalkersee
02-06-2004, 10:45 AM
One more thing I forgot. Ford had an updated part# on the MAF harness. I can not remember what it was or even what it looked like. It has been 5 years since I put one on. A good shop will be able to tell you if you have the updated one or not. I know they covered SOME Fords in the mid 90s. We rarely saw SCs in the shop though so I dont know. Try to have a buddy start it and do a GM tap test on the MAF. If there is no change do a wiggle test on the wires. What does the connector face look like?

tadmichael22
02-07-2004, 10:53 AM
From the harness the connector face is an oval with a 4 pin setup.
it clicks over the maf sensor. Aloso I bought the sensor from auto zone because I wasnt sure if that was the problem or not. I hated to go buy one from ford for $300 and that not be the problem and I would have wasted 300 for nothing. I tried 2 diff. ones from auto zone and neither of them acted any different (neither helped).
Tad

Randy N Connie
02-07-2004, 01:52 PM
Are you sure that the cam sensor is working right.
Do you have an extra one to swap to check this part out.

I have a C&L 76MM MAF, sample tube is PURPLE, with 42lb injectors

Randy

tadmichael22
02-09-2004, 09:07 AM
Not real sure if it is or not. I pulled codes and nothing came up. I was thinking about that but I dont have another one to swap out and I hate to keep changing parts to find out that it wasnt the prob. Does my problem sound like a cam sensor to you???
Tad

J57ltr
02-09-2004, 01:38 PM
Have you checked for vacuunm leaks?

XR7 Dave
02-09-2004, 02:08 PM
Some things don't sit right with me on this one.

1) I don't think the car should run without the MAF connected. Wouldn't 42lb injectors flood the car out? Yet he said there is no sign of flooding on the plugs.

2) The fact that it starts, shoots up to 3000rpm and then dies, tells me that there is no fuel after initial startup. RPM's climb as fuel is used up and then it dies. It can't be flooding out or you'd have wet plugs.

Are you sure that there is a constant 34-35psi fuel pressure after startup? I'm wondering if the AFPR is letting the fuel pressure drop after startup (ie. over responsive to vacuum). I would disconnect the MAF and start the car, and monitor fuel pressure with the car running.

tadmichael22
02-09-2004, 02:27 PM
Okay 2 answers here. I have checked for vacum leaks and have none. I put pressure into the nipple out of the back of the plenum where it goes to the boost/vacum guage. I started with 15psi and had none and went up to 20 the only place I had air was out of the end of the air inlet tube. I covered the end of it and let the 20psi run into it and the dipstick popped out from the pressure and that was it. No other leaks.
As far as the fuel pressure goes I have a guage on the rail and When I run it with the maf disconnected it stays at a steady 40psi. Yes the climbing up to 3000 rpms and instantly dying does sound like a fuel starvation problem but its unfortunately not.
I appreciate all of you sticking with me here and trying to help me out!! Tad

seawalkersee
02-09-2004, 02:56 PM
The computer does the value for the MAF. Did you look at the face of the connector and see if it is the new one? Did you do the tap test on it? When you say it just dies can you flutter the gas and keep it goin (sorry, you wrote that 3 pages ago and I dont remember)? Two more things come to mind. Crank sensor and EGR valve. If the valve is stuck open or cracked it will die but you will be able to flutter it and keep it runnin. You test it by puttin a vacuum pump to it. It should hold vacuum.

tadmichael22
02-09-2004, 03:09 PM
I did try tapping on it and wiggling the wires and there was no dofference. What do you mean by "the new one"?? Also it wont stay running at all even if I do flutter the gas pedal.
Tad

XR7 Dave
02-09-2004, 07:01 PM
So you are saying that it will not run with any MAF connected?

BTW, your fuel pressure should be 34-35psi at idle, not 40 unless you have disconnected the vac line to the FPR. But that won't make that much difference.

Randy N Connie
02-09-2004, 09:33 PM
Not real sure if it is or not. I pulled codes and nothing came up. I was thinking about that but I dont have another one to swap out and I hate to keep changing parts to find out that it wasnt the prob. Does my problem sound like a cam sensor to you???
Tad

I seen one SC that would idle ruff like it was out of fuel.And then the idle would
would go up a little.We checked every thing ,and it turned out to be the cam sensor.
But I have had my cam sensor go out a couple times, & it did not act like your SC.

RANDY

tadmichael22
02-10-2004, 08:36 AM
Correct it wont run with any maf connected. It wouldnt with my stock maf sensor and then I tried 2 Auto zone maf electronics and all were the same. I wouldnt think that all 3 electronics could have been bad. Before I tore my motor apart it ran perfect so my electronics were fine then. After rerbuilding it the stock electronics wouldnt work so thats what I thought was the problem. Its just hard to believe my factory electronics went bad and both az. ones were bad as well. But at this point I DUNNO!!
Oh and also my fuel pressure was adjusted to 40psi with the fpr line disconnected.
Tad

seawalkersee
02-11-2004, 06:35 PM
By the new one I meant the MAF connector. Anymore the more I think about it, it seems like the crank sensor. The only thing that puzzles me is why it died(s) with the MAF connected and still runs when its unplugged. And it does run up to 3k and then shuts off every time correct?

99GSXR750
02-11-2004, 09:42 PM
I just read a post by Bobgpz where he was having a similar problem. The car would idle up to 3000 rpm and then slowly die. Turned out to be a bad IAC valve. Sorry if this has already been discussed. Just figured I'd throw it out there.
Mike

tadmichael22
02-11-2004, 09:47 PM
Yes most of the time it will go up to 300rpm and die but sometimes it just sputters for a sec. and dies. When I am cranking the motor I do not have an up arrow on my guages either like I thought you have when you have a bad crank sensor. I wouldnt think it would be the IAC because it wont run with the throttle open either. No matter how much gas you give it it wont respond at all it justfalls on its face after 3000rpms.
Tad

99GSXR750
02-11-2004, 10:19 PM
According to bobgpz, you can disconnect the IAC valve and if it makes a dying goose sound then its bad. It might be worth a shot.

J57ltr
02-11-2004, 10:57 PM
It's not a crank sensor and it's not the IAC for sure.

Did you reset the fuel pressure? You had it a little high.

Jeff

seawalkersee
02-12-2004, 06:20 AM
When the car died, did the fuel pressure drop off as well or did it stay pumped up? I would now at this point find a breakout box and pin it out. It sounds like you are losing either crank snesor input or fuel. The car only needs fuel, fire, and air to continue to run. Are all of your hoses tight? If they are loose, Im kickin myself in the butt for not askin sooner. Put the car all the way back together if its not and then try.

XR7 Dave
02-12-2004, 09:24 AM
Quick way to check a cam sensor. Reconnect the MAF, unplug the cam sensor. Attempt to start the motor. Without the cam sensor signal the EEC will randomly select coil packs to fire. When it gets the right one it will start and run fine. The other times it won't want to start. So just try starting it a bunch of times in succession. Don't hit the gas or anything like that, it should just start right up and run ok when it guesses the right coil.

tadmichael22
02-12-2004, 11:43 AM
Jeff, as far as I know my fuel pressure should be fine. When I adjusted it I did it with the vacuum line on the fuel pressure reglator disconnected and set it to 40psi. With the line connected it does drop to around 35 or so. Chris, as far as my lines all being tight everything is a okay there. I double checked all of them and my fuel pressure does indeed stay up when it dies. Dave, I will have to try what you were suggesting because I havent tried that yet and at this point I'll try anything you guys can think of.
Tad

J57ltr
02-12-2004, 01:27 PM
I thought that you set the pressure with the line connected which would cause more fuel to be dumped.

I think that there may be a combination of problems that are causing your issue. Not sure what it is though.

Jeff

tadmichael22
02-12-2004, 02:48 PM
Okay I just tried disconnecting the cam sensor and starting it... Once again no luck!! :( It fired up and sputtered like always and died. I tried several times and nothin. I disconnected the maf afterwards and it started right up again??????????? I am rapidly running out of patience with this thing. But once again I do appreciate the replies!!! Hopefully you guys have another idea to try because right now I cant afford to take it to a mechanic so I have to get it goin myself. (with all your help of course)
Tad

seawalkersee
02-12-2004, 09:05 PM
Unplug the IAB sensor and try it. If it runs check the "91 sc wont idle" (or its close to that title). They walk you through it. I still think there are two problems though.

Brandon
02-12-2004, 10:05 PM
I still guarantee it's the MAFS. My car did the same thing as yours!!!

XR7 Dave
02-12-2004, 10:31 PM
Ya, time to start checking line voltages and resistances.

J57ltr
02-12-2004, 11:23 PM
Try this disconnect the intake tube from the TB and see if the car will run, leave the MAF connected.

Did you ever check the MAF output voltage?

Jeff

tadmichael22
02-13-2004, 07:29 AM
what should I do to check the maf output voltage?? and what should the numbers be at??
Tad

seawalkersee
02-13-2004, 12:54 PM
Someone posted earlier on how to check the MAF voltage. There is a MAF sensor on ebay rite now for like $20. Check it out.

tadmichael22
02-13-2004, 02:03 PM
The only one I saw was the one for an 89. Is that the same as a 93?

seawalkersee
02-13-2004, 02:22 PM
Dont know but its better then that Auto Zone crap you have on there now. All of them are different when you buy them from Ford but they are generic from most of the aftermarket places.

ThunderDave
02-13-2004, 04:31 PM
I think the maf on the 89 is a 55mm and a 93 has like a 70mm.

As long as the injectors were stock though, it would be ok for testing it.

Good luck!

David

tadmichael22
02-13-2004, 07:23 PM
okay guys, I got a new thing to throw into the mix now. I went out tonight and tried to unhook the inlet tube from the tb and leave the mafs connected like jeff suggested. I tried it several times and then I disconnected the maf and started it just to blow out the plugs a little and when it was running it seemed like it was struggling for air or something. When I would rev it up a little it would go instantly into boost? I have true duals on it so I felt both sides of the exhaust to see it they were hot or not. To my suprise the left side was cold and the right side I just about burnt my hand on it was so warm. I have no catalytic converters on it to be blocked up or resonators at this time either. I pulled the left rear plug to see what it looked like and it was a little wet but not bad at all like it was fireing. I didnt get a chance to check the right side yet though. Not sure why this is happening??
Tad

XR7 Dave
02-14-2004, 01:08 AM
Running the car like you have with 42lb injectors and no MAF has fouled the plugs. If they are wet at all then they are not firing. You will need to replace them to get it to run decently again. For now I would suggest getting non platinum plugs as they are much cheaper since they may foul again.

tadmichael22
02-17-2004, 03:53 PM
Okay guys. I just got some time here and I went out and changed my plugs once again. I did what Jeff said and connected the maf but disconnected the air inlet tube from the TB and just moved them aside while it is still plugged in. I turned the key and she fired right up and stayed running. I can tell my IAC is bad also because I had to keep my foot on the throttle a little to keep it running. Other than that it ran with the maf connected finally!!! Now the next question I have is why will it run with the air inlet tube disconnected but not with it connected??? Thanks
Tad

David Neibert
02-17-2004, 05:20 PM
Something is wrong with the MAF or the calibration.

David

seawalkersee
02-17-2004, 09:35 PM
Dave is right. Sorry to sound bad but this is what we have been telling you since the start of the post five pages ago. However it has been mind stimulating. I actually thought long and hard about this post for several hours at times.

tadmichael22
02-18-2004, 06:56 AM
Well thanks guys! So basically my 2 auto zone sensors are junk. If I go get a FORD mafs then it (should) run. (SHOULD)!!

sho taurus
02-19-2004, 01:18 AM
is this maf sit up for 42 lbs injectors and supercharged?

tadmichael22
02-19-2004, 06:50 AM
Yeppers.