What are symptoms of bad TFI module?

jpumpkinn · 11-06-2002, 12:15 AM

What are some symptoms of a bad TFI module?

I am experiencing complete loss of all lowend power and a really low idle. Almost to the point where it wants to shut off. I originally thought it was the pump but I just replaced it. The problem seemed to only get worse.

joe4speed · 11-06-2002, 02:36 AM

My buddys car would not start most of the time, especially when it was hot.
Changed the TFI and never had a problem again!

PKRWUD · 11-06-2002, 04:10 PM

Typical bad TFI situation:

Driving for 20 minutes, pull into a gas station. Fill up the car, and then it won't start. Spend 10 minutes under the hood pushing this, and banging that, and it suddenly starts, convincing you that you have a loose wire somewhere.

How's your fuel filter?

Take care,
ÅChris

Coupe50h · 11-06-2002, 08:11 PM

Quote:

Originally posted by jpumpkinn
What are some symptoms of a bad TFI module?

I am experiencing complete loss of all lowend power and a really low idle. Almost to the point where it wants to shut off. I originally thought it was the pump but I just replaced it. The problem seemed to only get worse.

jpumkin, i know we live on opossite sides of s.a, but i have a code scanner, or just go buy you one at autozone, i think i paid 30$, but a good tool to have....let me know, i'll be glad to run a scan on it, maybe at the track....

Does it die on you?

jpumpkinn · 11-07-2002, 09:52 AM

The car does not die on me. It just idles so low that the engine is fighting to stay on. Even worse I have no power. If I was going to get going on a upward incline I don't think the car would make it. I am going to try replacing the TFI module this weekend.

As for the fuel filter its only about 6 months old.

I appreciate the input let me know if you have any Ideas.

jpumpkinn · 11-07-2002, 09:56 AM

PCKWUD-

What you described sounds very similar to my problem. I would pull into a drive thru and it would just start to idle very low untill it died. 10 min later it would start up again. I hope it is the TFI module.

PKRWUD · 11-07-2002, 10:30 AM

I doubt that it is. The TFI acts more like a light switch; it either is working or it's not working. Rarely is it working very weakly.

You need to isolate where the problem is. Try this:

Next time it is idling low, about to stall, unplug one of the rubber caps on the vacuum tree on your firewall, and see what happens. Tell me if the idle goes up, or if the engine stalls.

Take care,
ÅChris

jpumpkinn · 11-07-2002, 11:05 PM

PKRWUD

Seems that you think it could be another problem. The problem was only occational and random. Then I replaced my fuel pump and the problem became constant. after knowing this do you still think it could be something else?

PKRWUD · 11-07-2002, 11:54 PM

It's one of three things. Either:
1) Too much air/too little fuel,
2) Too much fuel/too little air, or
3) An ignition problem.

I'm trying to get you to help me rule some things out. Did you do what I asked you to? What happened?

Do you have an EFI fuel pressure tester? DMM? Compression gauge?

Help me help you.

Take care,
ÅChris

Coupe50h · 11-07-2002, 11:59 PM

My car idles low too, but doesnt die, i just have vacuum leaks from removed smog equipment,

maybe your mass air is bad, it'll take some time, but we'll figure it out...keep posted.

btw, saying you have no power is what makes me think it could be the maf, do you still have cat converters?

sn95gt19 · 11-08-2002, 10:44 AM

i would check out the coil too.

Agent_4573 · 11-08-2002, 01:23 PM

how is the maf related to cat converters? i have a bigger maf but when i put it on i have no power. its for the right injectors andi don't have cats....

jpumpkinn · 11-09-2002, 04:15 PM

Well everyone PKRWUD was right as usual! It was not the TFI module. I changed it this morning and the car runs better but is still doing the same thing. I am going to try checking the vacuum lines on the tree like PKRWUD said. I'll let you know what happens.

Also, I can hear an exhaust leak putting when I hit the gas. The pipes need to be re tightened. Could this contribute to the problem?

Thanks for your help everyone.

jpumpkinn · 11-09-2002, 05:20 PM

ok, PKRWUD

The problem seems to have gotten much better. I drove it around for 20 min and it did not bog down but one time. When the engine seemed to be wanting to bog down again I removed one of the vacuum caps. The engines Idle went up. to about 900 to 1000 rpms from 500.

I still feel a lack of power in the low band range but not even close to as bad as it was.

What do you think?

PKRWUD · 11-09-2002, 05:36 PM

Well, it's not a lean condition, because the engine would have stalled when you removed the vacuum cap. I doubt it's a rich condition because you would smell it, and have smoke. Since the TFI helped some, I suspect it's an ignition problem, possibly the coil. If you have access to another coil that you know is good, try it and see if things improve.

Have you cleaned the IAB or adjusted the TPS recently? If you have, and didn't reset the ECM afterwards, that may be pert of the problem as well.

Try a friends coil.

Take care,
~Chris

Coupe50h · 11-09-2002, 08:39 PM

Quote:

Originally posted by Agent_4573
how is the maf related to cat converters? i have a bigger maf but when i put it on i have no power. its for the right injectors andi don't have cats....

It's not, it was supposed to be a seperate question, but i say this because clogged cats would severely kill power.

mimicons · 11-09-2002, 10:09 PM

My scenario was like this....Drive for a while, especially on the highway, and then as soon as I pull off, the engine idled really low, and then died. If I let the car sit for a few minutes, it was fine for a little longer.

The part is dirt cheap, and the only thing I can tell you is to invest in one of the special wrenches (I got mine for $3 at Advance Auto) and also keep a spare TFI module. This is a problem that the fox's are notorious for.

Good luck...Chances are that when you replace yours, the problem will be solved.

Mike

jpumpkinn · 11-09-2002, 11:58 PM

SMELL IT! I have noticed the strong smell of gas and white smoke coming from the exhaust until the engine warms up. Could I be running to rich? What do I have to do to fix this?

jpumpkinn · 11-10-2002, 12:04 AM

I have not adjusted the TPS recently.

After driving earlier I did notice a strong gas smell and some white exhaust in the morning. Could I be to rich? Could this new fuel pump have changed something? What do I have to do to fix running to rich?

Coupe50h · 11-10-2002, 01:31 PM

Well i undersatand o2 sensors will give a check engine light (so those probaly arent it), but sounds like something like that, also brings me to believe the maf sensor, sorry i cant be more helful, im stumped, but good luck.

11-06-2002, 12:15 AM	#1
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	What are symptoms of bad TFI module? What are some symptoms of a bad TFI module? I am experiencing complete loss of all lowend power and a really low idle. Almost to the point where it wants to shut off. I originally thought it was the pump but I just replaced it. The problem seemed to only get worse. __________________ Keep On Truckin!!

11-06-2002, 02:36 AM	#2
joe4speed He said Member...heh, heh Join Date: Sep 1999 Location: Jupiter, Florida U.S.A. Posts: 3,718	My buddys car would not start most of the time, especially when it was hot. Changed the TFI and never had a problem again! __________________ *Joe!* 1988 GT, 13.58@101mph Check out my listing! Click here! Or my website:www.joe4speed.com

11-06-2002, 04:10 PM	#3
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Typical bad TFI situation: Driving for 20 minutes, pull into a gas station. Fill up the car, and then it won't start. Spend 10 minutes under the hood pushing this, and banging that, and it suddenly starts, convincing you that you have a loose wire somewhere. How's your fuel filter? Take care, ÅChris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

11-07-2002, 09:52 AM	#5
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	The car does not die on me. It just idles so low that the engine is fighting to stay on. Even worse I have no power. If I was going to get going on a upward incline I don't think the car would make it. I am going to try replacing the TFI module this weekend. As for the fuel filter its only about 6 months old. I appreciate the input let me know if you have any Ideas. __________________ Keep On Truckin!!

11-07-2002, 09:56 AM	#6
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	PCKWUD- What you described sounds very similar to my problem. I would pull into a drive thru and it would just start to idle very low untill it died. 10 min later it would start up again. I hope it is the TFI module. __________________ Keep On Truckin!!

11-07-2002, 10:30 AM	#7
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I doubt that it is. The TFI acts more like a light switch; it either is working or it's not working. Rarely is it working very weakly. You need to isolate where the problem is. Try this: Next time it is idling low, about to stall, unplug one of the rubber caps on the vacuum tree on your firewall, and see what happens. Tell me if the idle goes up, or if the engine stalls. Take care, ÅChris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

11-07-2002, 11:05 PM	#8
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	PKRWUD Seems that you think it could be another problem. The problem was only occational and random. Then I replaced my fuel pump and the problem became constant. after knowing this do you still think it could be something else? __________________ Keep On Truckin!!

11-07-2002, 11:54 PM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	It's one of three things. Either: 1) Too much air/too little fuel, 2) Too much fuel/too little air, or 3) An ignition problem. I'm trying to get you to help me rule some things out. Did you do what I asked you to? What happened? Do you have an EFI fuel pressure tester? DMM? Compression gauge? Help me help you. Take care, ÅChris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

11-07-2002, 11:59 PM	#10
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	My car idles low too, but doesnt die, i just have vacuum leaks from removed smog equipment, maybe your mass air is bad, it'll take some time, but we'll figure it out...keep posted. btw, saying you have no power is what makes me think it could be the maf, do you still have cat converters? __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

11-08-2002, 10:44 AM	#11
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	i would check out the coil too. __________________ 95gt lazer red (98 cobra clone) Rice Haters Club Member #116

11-08-2002, 01:23 PM	#12
Agent_4573 Registered Member Join Date: May 2002 Location: New Jersey Posts: 375	how is the maf related to cat converters? i have a bigger maf but when i put it on i have no power. its for the right injectors andi don't have cats.... __________________ '89 LX 5.0, off-road h pipe, flowmaster muffs, underdrive pulleys, rebuilt WC T-5, King Cobra Clutch, 65mm throttle body, Explorer Upper/GT40 lower, Lakewood Rear Lift Bars. 76mm C&L Mass air w/ inlet pipe, Twisted wedge heads w/ stage 2 port,polish, MAC equal length shorties, Billet AFPR, 255LPH fuel pump, fresh low end w/ 10.5:1 compression. If anyone ever wants to go to Raceway Park in Englishtown New Jersey, give me a shout. RICER HATERS CLUB MEMBER 87! www.ricehatersclub.com

11-09-2002, 04:15 PM	#13
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	Well everyone PKRWUD was right as usual! It was not the TFI module. I changed it this morning and the car runs better but is still doing the same thing. I am going to try checking the vacuum lines on the tree like PKRWUD said. I'll let you know what happens. Also, I can hear an exhaust leak putting when I hit the gas. The pipes need to be re tightened. Could this contribute to the problem? Thanks for your help everyone. __________________ Keep On Truckin!!

11-09-2002, 05:20 PM	#14
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	ok, PKRWUD The problem seems to have gotten much better. I drove it around for 20 min and it did not bog down but one time. When the engine seemed to be wanting to bog down again I removed one of the vacuum caps. The engines Idle went up. to about 900 to 1000 rpms from 500. I still feel a lack of power in the low band range but not even close to as bad as it was. What do you think? __________________ Keep On Truckin!!

11-09-2002, 05:36 PM	#15
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Well, it's not a lean condition, because the engine would have stalled when you removed the vacuum cap. I doubt it's a rich condition because you would smell it, and have smoke. Since the TFI helped some, I suspect it's an ignition problem, possibly the coil. If you have access to another coil that you know is good, try it and see if things improve. Have you cleaned the IAB or adjusted the TPS recently? If you have, and didn't reset the ECM afterwards, that may be pert of the problem as well. Try a friends coil. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

11-09-2002, 10:09 PM	#17
mimicons Registered Member Join Date: Aug 2001 Location: Atlanta Area, USA Posts: 42	My scenario was like this....Drive for a while, especially on the highway, and then as soon as I pull off, the engine idled really low, and then died. If I let the car sit for a few minutes, it was fine for a little longer. The part is dirt cheap, and the only thing I can tell you is to invest in one of the special wrenches (I got mine for $3 at Advance Auto) and also keep a spare TFI module. This is a problem that the fox's are notorious for. Good luck...Chances are that when you replace yours, the problem will be solved. Mike

11-09-2002, 11:58 PM	#18
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	SMELL IT! I have noticed the strong smell of gas and white smoke coming from the exhaust until the engine warms up. Could I be running to rich? What do I have to do to fix this? __________________ Keep On Truckin!!

11-10-2002, 12:04 AM	#19
jpumpkinn Registered Member Join Date: Jun 2001 Location: san antonio Texas usa Posts: 127	I have not adjusted the TPS recently. After driving earlier I did notice a strong gas smell and some white exhaust in the morning. Could I be to rich? Could this new fuel pump have changed something? What do I have to do to fix running to rich? __________________ Keep On Truckin!!

11-10-2002, 01:31 PM	#20
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	Well i undersatand o2 sensors will give a check engine light (so those probaly arent it), but sounds like something like that, also brings me to believe the maf sensor, sorry i cant be more helful, im stumped, but good luck. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

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