Need Help Bad! Mechanic cant find problem! - Page 2

DRASTiK · 02-28-2002, 03:04 PM

Why can't you just cut and splice some wire to extend the O2 sensor connections?

As far as TFI, if that doesn't work, I know the PIP inside the dizzy can cut out for split second and the cut right back on. This is hard to catch without a quick multimeter.

Just my $.02
Dave

NotchJohnson · 02-28-2002, 05:06 PM

Hey guys, I dont have any cats or smog stuff on my car. I have mac longtubes running intop a prochamer then to a mac cat-back. I dont have a vaccum guage either. The odometer reads 79,000 but the more i mess with the car, the more i wonder if its really true. The mechanic said he couldnt pull any codes from it because the car was so mixed and matched. I have no idea what the history of the car is, the carfax report doesnt say anything but something is definitely screwy. The car is an 87, but the motor is mass-air. Werent 87-88 models speed density? Anyway, I am going to look at the car tomorrow since I am home now. Hopefully I can get this straightened out. Thanks - John

NotchJohnson · 02-28-2002, 05:07 PM

Oh and hey Hiflow, did your car seem to run ok for the first few minutes then get worse, or was it running crappy all the time?

HiFlow5 0 · 02-28-2002, 05:51 PM

Quote:

Originally posted by NotchJohnson
Oh and hey Hiflow, did your car seem to run ok for the first few minutes then get worse, or was it running crappy all the time?

Oh gees its been almost 4 years since I owned that car....ummm lets see. It started just as back firing once and a while. Then a few months later it sputtered a lot more and started getting rougher. At an idle the car felt like it had a cam in it, and when I went to put it in drive it would die. If I raised the rpms's at idle it would smooth out, but not a hole lot. Hope that helps some.
-Craig

DRASTiK · 02-28-2002, 06:23 PM

John,
It sounds like you're going through what I went through when I first got my 88. Someone's hands had been all in it that didn't know what they were doing. It had been converted to mass air and when I tried to pull the codes, I had to do some crazy stuff just to get the code reader to pull anything. I had to connect one wire to the positive side of the battery, then another to the EEC ground, or something like that (sorry it's been a while). Then it would pull like 12 codes. I replaced the EEC, and that fixed part of my problems, but not all of them. Anyways the best thing that I can suggest you do is grab a haynes manual for your car and pull the passenger side kick panel off and start referencing wires. Make sure they're where they need to be especially for the MAF. There are 4 wires from the MAF that SOMEBODY obviously put in there, or at least attempted to. Make sure the wiring diagram matches up with your wiring. Then if you still have problems, try and borrow a friend's EEC out of another 89-93, and see if that makes a difference. If you don't already have one, then go get a code scanner from the parts store for about $35.
Dave

juiceman · 02-28-2002, 08:02 PM

im going to give you some advice that im sure pkrud and others will agree with. the first thing you need to do is fix what you know is wrong. you have a computer car and you have computer sensors not even connected. the comp needs to have sensors to properly run the motor. if you didnt hook up your modem would it work? well the car is the same way. next, the mechanic couldnt pull codes? it doesnt matter where the comp came from or when it was put in it still has memory. so if your mechanic knows how to hook up the box then it will give some code, at least an ok code. now im not saying any of those things are your problem and many things as you can see can cause the same reaction on the motor but you need to start at A before you go to B. each part on the motor works together, if you break one thing it will affect the other in some way. one question, didnt your sig say going to carbed? if so why bother fixing the problem, just go carbed now

Unit 5302 · 02-28-2002, 08:50 PM

Ummm... yeah. Your mechanic is a moron. Your car isn't going to run for **** without the O2 sensors hooked up. I suggest you get a longer harness, or an extention harness.

NotchJohnson · 02-28-2002, 11:20 PM

Yeah I was going to go carbed when i first decided to build a motor because my buddy was running a carbed 306 and it was making awesome power, he told me it was cheap so i figured thats what i would do. Since then ive gone off to school and have decided to keep the car efi, since I take the car 180 miles to school. I have added a few mods to the stock motor such as a cold air kit, exhaust and all the small stuff. I have a shortblock for a 331, I just have to wait until summer so i can get a good job and finish it. Anyway I did drive the car earlier and it runs fine at cruising speed now. what the hell! last time i drove it it ran ok for a few mins then got crappy. I just drove the car 25 miles and the damn thing only acted up at idle. This is really ticking me off. I am going to hook up the o2 sensors tomorrow first thing. Does it make sense that the car ran ok for almost 2 months without them being hooked up, but now suddenly went screwy? Thanks for all the suggestions and help because im pretty lost. -John

Shogun · 03-01-2002, 12:42 AM

I would bet that your problem stems from the disconnected O2's. First, did the car run correctly before you put in the long tubes? If so, I am all most certain it is the disconnected O2s. In your first post, you mentioned that the car ran fine cold until it warmed up. Here's how I think why, at around 160F the EEC gives the O2's air/fuel ratio control for the engine. I believe the car ran ok before the rain incendent is because the EEC uses an adaptive fuel mapping logic, it watches for variations in the O2 sensor signal. If the EEC senses that the O2 singal tends to bias toward a lean or rich condtion the EEC will try to compensate for a better 14.0:1 ratio. Which might explain why the car still ran because the computer tried to keep the fuel ratio close until it could no longer compensate or until it recieved a new crazy singal from your water shorted O2 connector plugs. Futhermore, the EEC is constantly monitoring the input/output signals to the computer looking for variations, and when it finds one, it will assign a code to it based on the findings/variations from the norm and store it in memory until you pull them out. And as for your last entry you mentioned the the car is staring to run a little better, that is because the computer is adapting to the new conditions as best it can. My suggestion is to either get new O2's with 16'' leads or buy the extensions for your exsiting O2's but if they are the originals it might be a good idea to replace them. Sorry for such a long post.. but I too have a highly modified stang and have been wrestling with the surging idle FOREVER until I finally sat down and learned how the whole system works. Now she purrs like a kitten. Ok I'm done now.

GreenPony · 03-01-2002, 09:19 AM

Lemme get this straight since i have an offroad h pipe , i do not have my 02 sensors plugged...Could this be bad?, What kinda problems should i look for if something starts to identify it as o2 sensor wires?

NotchJohnson · 03-01-2002, 09:53 AM

Man I sure hope your right Shogun. What you say really makes sense to me so I hope thats it. Im getting ready to go put the car on a lift now and hook the o2 sensors up. Thanks alot for the help and Ill let you know if it works - John

Shogun · 03-01-2002, 05:35 PM

Well, a hole host of things could happen, such as poor idle quaility, hesititations or backfires at low speed operation, and increased fuel consumtion to name a few.

Shogun · 03-01-2002, 05:36 PM

Quote:

Originally posted by NotchJohnson
Man I sure hope your right Shogun. What you say really makes sense to me so I hope thats it. Im getting ready to go put the car on a lift now and hook the o2 sensors up. Thanks alot for the help and Ill let you know if it works - John

hey glad I could help I hope it works for ya!

gtsr515 · 03-02-2002, 04:09 PM

The 02's MUST be hooked up man! those are the sensors that are key to your proper air/fuel ratio! no wonder it won't run right.

WOW

02-28-2002, 05:06 PM	#22
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	Hey guys, I dont have any cats or smog stuff on my car. I have mac longtubes running intop a prochamer then to a mac cat-back. I dont have a vaccum guage either. The odometer reads 79,000 but the more i mess with the car, the more i wonder if its really true. The mechanic said he couldnt pull any codes from it because the car was so mixed and matched. I have no idea what the history of the car is, the carfax report doesnt say anything but something is definitely screwy. The car is an 87, but the motor is mass-air. Werent 87-88 models speed density? Anyway, I am going to look at the car tomorrow since I am home now. Hopefully I can get this straightened out. Thanks - John __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

02-28-2002, 05:07 PM	#23
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	Oh and hey Hiflow, did your car seem to run ok for the first few minutes then get worse, or was it running crappy all the time? __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

02-28-2002, 11:20 PM	#28
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	Yeah I was going to go carbed when i first decided to build a motor because my buddy was running a carbed 306 and it was making awesome power, he told me it was cheap so i figured thats what i would do. Since then ive gone off to school and have decided to keep the car efi, since I take the car 180 miles to school. I have added a few mods to the stock motor such as a cold air kit, exhaust and all the small stuff. I have a shortblock for a 331, I just have to wait until summer so i can get a good job and finish it. Anyway I did drive the car earlier and it runs fine at cruising speed now. what the hell! last time i drove it it ran ok for a few mins then got crappy. I just drove the car 25 miles and the damn thing only acted up at idle. This is really ticking me off. I am going to hook up the o2 sensors tomorrow first thing. Does it make sense that the car ran ok for almost 2 months without them being hooked up, but now suddenly went screwy? Thanks for all the suggestions and help because im pretty lost. -John __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

03-01-2002, 12:42 AM	#29
Shogun Registered Member Join Date: Feb 2002 Location: Nebraska Posts: 86	Almost bet on O2's I would bet that your problem stems from the disconnected O2's. First, did the car run correctly before you put in the long tubes? If so, I am all most certain it is the disconnected O2s. In your first post, you mentioned that the car ran fine cold until it warmed up. Here's how I think why, at around 160F the EEC gives the O2's air/fuel ratio control for the engine. I believe the car ran ok before the rain incendent is because the EEC uses an adaptive fuel mapping logic, it watches for variations in the O2 sensor signal. If the EEC senses that the O2 singal tends to bias toward a lean or rich condtion the EEC will try to compensate for a better 14.0:1 ratio. Which might explain why the car still ran because the computer tried to keep the fuel ratio close until it could no longer compensate or until it recieved a new crazy singal from your water shorted O2 connector plugs. Futhermore, the EEC is constantly monitoring the input/output signals to the computer looking for variations, and when it finds one, it will assign a code to it based on the findings/variations from the norm and store it in memory until you pull them out. And as for your last entry you mentioned the the car is staring to run a little better, that is because the computer is adapting to the new conditions as best it can. My suggestion is to either get new O2's with 16'' leads or buy the extensions for your exsiting O2's but if they are the originals it might be a good idea to replace them. Sorry for such a long post.. but I too have a highly modified stang and have been wrestling with the surging idle FOREVER until I finally sat down and learned how the whole system works. Now she purrs like a kitten. Ok I'm done now.

03-01-2002, 09:19 AM	#30
GreenPony Registered Member Join Date: Feb 2002 Location: Louisiana Posts: 43	02 sensors? Lemme get this straight since i have an offroad h pipe , i do not have my 02 sensors plugged...Could this be bad?, What kinda problems should i look for if something starts to identify it as o2 sensor wires? __________________ 92 GT Hurst Short Throw, BBK Equal Lengths, BBK OFF Road H PIPE,@ Chamber Flows, FLex Fan, K&N.Dying For More!!May not be the fastest but sure sound Good!

02-28-2002, 03:04 PM	#21
DRASTiK Registered Member Join Date: May 2001 Location: Yuma, AZ Posts: 536	Why can't you just cut and splice some wire to extend the O2 sensor connections? As far as TFI, if that doesn't work, I know the PIP inside the dizzy can cut out for split second and the cut right back on. This is hard to catch without a quick multimeter. Just my $.02 Dave

02-28-2002, 06:23 PM	#25
DRASTiK Registered Member Join Date: May 2001 Location: Yuma, AZ Posts: 536	John, It sounds like you're going through what I went through when I first got my 88. Someone's hands had been all in it that didn't know what they were doing. It had been converted to mass air and when I tried to pull the codes, I had to do some crazy stuff just to get the code reader to pull anything. I had to connect one wire to the positive side of the battery, then another to the EEC ground, or something like that (sorry it's been a while). Then it would pull like 12 codes. I replaced the EEC, and that fixed part of my problems, but not all of them. Anyways the best thing that I can suggest you do is grab a haynes manual for your car and pull the passenger side kick panel off and start referencing wires. Make sure they're where they need to be especially for the MAF. There are 4 wires from the MAF that SOMEBODY obviously put in there, or at least attempted to. Make sure the wiring diagram matches up with your wiring. Then if you still have problems, try and borrow a friend's EEC out of another 89-93, and see if that makes a difference. If you don't already have one, then go get a code scanner from the parts store for about $35. Dave

02-28-2002, 08:02 PM	#26
juiceman Registered Member Join Date: Jan 2001 Location: ny Posts: 197	im going to give you some advice that im sure pkrud and others will agree with. the first thing you need to do is fix what you know is wrong. you have a computer car and you have computer sensors not even connected. the comp needs to have sensors to properly run the motor. if you didnt hook up your modem would it work? well the car is the same way. next, the mechanic couldnt pull codes? it doesnt matter where the comp came from or when it was put in it still has memory. so if your mechanic knows how to hook up the box then it will give some code, at least an ok code. now im not saying any of those things are your problem and many things as you can see can cause the same reaction on the motor but you need to start at A before you go to B. each part on the motor works together, if you break one thing it will affect the other in some way. one question, didnt your sig say going to carbed? if so why bother fixing the problem, just go carbed now

02-28-2002, 08:50 PM	#27
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Ummm... yeah. Your mechanic is a moron. Your car isn't going to run for **** without the O2 sensors hooked up. I suggest you get a longer harness, or an extention harness.

03-01-2002, 09:53 AM	#31
NotchJohnson Registered Member Join Date: Oct 2001 Location: Florida Keys Posts: 593	Man I sure hope your right Shogun. What you say really makes sense to me so I hope thats it. Im getting ready to go put the car on a lift now and hook the o2 sensors up. Thanks alot for the help and Ill let you know if it works - John __________________ 89 notch-finally not stock!! ported gt40's, ported cobra intake, 65mm tb, 75mm maf, mac cai, lt's,prochamber, fms 1.6 rr, 125 shot.

03-01-2002, 05:35 PM	#32
Shogun Registered Member Join Date: Feb 2002 Location: Nebraska Posts: 86	o2's Well, a hole host of things could happen, such as poor idle quaility, hesititations or backfires at low speed operation, and increased fuel consumtion to name a few. __________________ Proud RHC member #99 1990 Mustang GT Trick Flow heads,F303,Mac cold air,FMS 65mm tb,73mm ma,FMS 1.6,GT-40 intake,MSD igintion,NOS Big Shot@150,Mac equal shorties,Mac h-pipe,American Thunder flows,Centerforce dual friction,TTC 3550,alm drive shaft, 3.73's, HPM subframes, k-member brace, strut tower brace.. amongst others.

03-02-2002, 04:09 PM	#34
gtsr515 Registered Member Join Date: Nov 2001 Location: Sunny, Hot, Sebring, Florida Posts: 725	The 02's MUST be hooked up man! those are the sensors that are key to your proper air/fuel ratio! no wonder it won't run right. WOW __________________ Remember...2nd place is 1st place for losers!

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