maxont

1987 tpi 350 map sens. car just turns off at stop lights sometimes... starts right back up no problem. where should begin looking? this car has always done this

1quik4

Bad injector??? That was my problem, same motor...

baliva1

Check your IAC valve

maxont

injectors are good, how do i check the iac valve?

burnout88

I would replace the ign. module in the distubutor and check if the pickup in the dist. is falling apart. Also sometimes this could be a bad ECM or flooding from leaking injectors.

One of two things is happening. You are losing spark or fuel, or over loading with fuel.

9014josh

iTrader: (1)

i am also vry curious ab this cuz i have the same damn problem...just randomly at lights sometimes it'll give no warning and just die...i know my comp is good,ive changed my distributor and my iac and my TPS sensor as well and still nothing!!! mines an 87 TA with the 305 TPI Let me know if you find this problem please!

maxont

problem still accuring

9014josh

iTrader: (1)

i wonder if this could be a possible fuel pump problem?

maxont

plenty of fuel pressure

StevenB L98/LS1

What all have you checked and replaced? so we can narrow down the problem.

gp90gta

iTrader: (1)

If you start the car and put in drive will it stall?

sloick

oil pressure switch?

9014josh

iTrader: (1)

mine will only stall occasionally at a stop sign or at a red light...like no warning just die out..and throw it in nuetral and bam it starts right back up again no problem at all...its REALLY annoying

maxont

9014josh explained it perfectly... but mine will sometimes die when i put it into reverse to back out of the garage... not very often though

maxont

i have checked ignition (new cap & rotor)? plugs, fuel pressure, injectors, map sensor (awhile back), tps, the coolant sensor thing on the front of the manifold, and others.....computer tells me nothing... i have forgotten what other things i have checked over the past year

9014josh

iTrader: (1)

hmmm...have you ever had it brought to a shop?

gp90gta

iTrader: (1)

did you check the egr and the port for carbon build up?

LuckyGen3

You might want to check for a vacuum leak somewhere around the Intake Plenum. One thing you could try (and it's simple) is to adjust your TPS for a fast idle while the car is in closed loop (about 120 degrees on the temp meter). You will probably get a code by doing so but if it keeps the car running when you come to stop it helps in trouble shooting the issue. After you adjust the TPS if idle drops and then picks back up at a stop it will be a leak in manifold pressure which means a vacuum leak of some kind. Most likely due to a bad gasket somewhere in the plenum or the vacuum lines connected to it. Also, once you changed all of the "tune up" components did you adjust the timing properly? You must disconnect the Tan/Blk stripe wire. Most people mistakingly disconnect the Tan wire from the coil. The correct wire will be close to the passenger side firewall. I hope this helps.

maxont

thanks for all the reply's guys... i think the car is just destined to do this forever

WSX123

iTrader: (1)

no because mine does the same thing, theres alot of people having this issue from reading the posts, gotta be something that no one has figured out yet.

LuckyGen3

maxont or wsx123...have either of you checked for the vacuum leak? There are actually 3 reasons it would die while cold and in gear.
1. Vacuum leak-You could have an issue with your intake gaskets. For TPI there are several.
2. Idle Air Control Valve-If it sticks your idle will drop dramatically under load. If you can stop it from dying under load by adjusting the idle using the TPS then you are on the right track.
3. Blown head gasket-With this one you will need to put your hand under the exhaust at high idle and smell for antifreeze.

The TPI motors are known to be a bit touchy.
Prior to 1989 most did not have a MAP sensor and would report codes 22, 33, 34, 36 for a vacuum leak involving the intake manifold.

The codes 33,34,36 all correspond to either the MAP or the MAF depending on the year of your vehicle and not the engine code.

If you clear codes and then get all 4 codes once the care gets into closed loop (120 on the temp) then it is most likely an Intake Manifold issue.

The way the sensors work:
1: The car starts and the computer advances the timing for initial engine sensor checks.
2: The computer checks sensors at idle and temperature rises.
3: Motor enters "Closed Loop"- At approximately 100 *F the computer has checked all sensors and has determined that the motor is ready for load.
4: Car goes into gear-Computer adjust timing based on TPI manifold pressure (which should be at it's highest). Also, Computer checks MAF, TPS, and MAP (in later models). Before MAP sensors the computer was fully dependant on the TPS and MAF sensors to tell it if the pressure was correct. This is where you will get the codes because the computer doesn't compute the numbers with a vacuum loss.
5: Car is in gear and the throttle is floored-Computer activates all injectors. Computer ignores manifold pressure (initially). Manifold pressure will be at it's lowest at this point. Once the throttle is released, the computer attempts to regulate ignition, fuel delivery, and intake pressure.

Basically, if you lose any of the components required to close the loop you will have issues.
This does not include the O2 sensor which will also have a big effect

If you want to do it on the cheap, then follow the instructions above and let me know the results.
I believe that if you give a man a fish he can't fix his car. But if you tell him how his Gen 3 works he will have happiness forever!!

maxont

luckygen,
thank you for the post, very informative!
Definatly not a blown head gasket, the car did this before and after the motor was rebuilt. could easily be a vacuum leak that i have just not found. Idle air control valve, im not really sure how to adjust the tps to stop it from dying. i get no codes and there is no intake manifold leakage due to recent replacement. now that i think about it more sometimes when the car is on a small downhill slop while im waiting at a stop light the car will try to die like it normally does but it catches itself at about 200rpms and revs back up to 7-800 and repeats itself a couple times before leveling out. i noticed the other night the vacuum on my egr solenoid was bypassed so i hooked it up how it was suppose to be.... but still the problem exsists. couple thoughts in there maybe a few of you can brew on... the slope thing has me a bit puzzled

pandin

I had a vacuum leak, the screws that hold the TPI plate on the top of the TB were loose. As the TB heated up the leak was bigger and after a cool down, it was less (3 to 4 screws were loose). Just had to retighten them.

caid1985

Im having a bit similar problem, mine will die out at the idle after running about 30 to 40 minutes, its not exact. But mine wont start back, but if you let it sit and cool down it will. So whatever is causing mine to get ugly is something getting hot I assume. When mine dies though it acts like its outta gas. One thing though, mine has a plate blocking off the hole for the egr valve, so I dont know what kind of effect that has overall.

9014josh

iTrader: (1)

WE NEED TO FIGURE THIS OUT!

lbackr40

I have a 92 5.7 Heritage Edition. Mine does the exact same thing. Car runs perfect at startup and for the first 20 - 30 minutes. After that I get a rough idle at stops, occasional bog upon take-off; and occasional stall when shifting into reverse or drive. I also hear a slight ticking from the engine when hot.

Anyone know any TPI experts in Northern Illinois?/Southern Wisconsin?

9014josh

iTrader: (1)

whats weird about this is that my car seems to have been doing this les and less maybe... could this be something as stupid as a fuel filter maybe?

pandin

Plugged fuel filters act as governors, when they start to plug up. Below a certain pulse width everything is fine, above that value, it starts to run lean and will maybe not run over say a certain rpm/mph, say 50 mph. As the filter gets more plugged up, this rpm/mph leanness starts at a lower number.

Low fuel pressure at higher loads is another sign.

1quik4

Any updates on this.. I have the same problem and need to fix this!!!!!

KatsCam

Just a thought...
The only time my car has ever died, twice, years apart but a few times in a row, it was my O2 sensor, which regulates your ail/fuel mixture. Sounds crazy, but that small part controls a lot more and affects a lot more than you think it does.
Talking about the front one by the exhaust manifold. And it won't always throw code when it's going either.

1quik4

You may be onto to something here.. I will replace it with a new one and see what happens.. Hell, doesn't hurt I guess...

9014josh

iTrader: (1)

anyone figure anything out?

lbackr40

A set of remanufactured Bosch Type III's from FIC fixed my problem.

Njs305t/a

It could just need an idle speed motor

elco86

Do not know if you guys had this problem fixed but, my brother had the same problem on his '91 bird and we spent hundreds trying to fix it, from cats to TPS sensors, it turned out to be his timing was a bit off. His car would turn on with no problem and after warming up the idle would go low then catch and eventually die, mainly at stops in gear. Redo the timing by unplugging the tan/wht wire the proper way and it may help, just put it back to spec. Good luck.

89iroc-z559

the same thing was happening to mine and it was the fuel injectors that were messing up the computer got new fuel injectors and computer and it fixed the problem