Hi guys, I just picked up my first TPI car and really don't know much at all about the system. It's a '91 305 TPI/5-Speed and it was parked for 3 years or so before I bought it. I drained the fuel, added fresh fuel and a new filter and fired it up. It was running a tad bit rough and I didn't think much of it because I still need to change the cap/rotor/coil and do a general tune up. Anyways, I took it around the block a few times(still running a little rough, but not that bad) and decided to take it to go put more fresh fuel in it. I turned it off, filled it with fresh gas, and it would not start-it wouldn't even fire. The only way it would fire at all was to hold it to the floor while turning it over and then it would only run above 3,000 rpm and not idle at all. I let it sit for a hour and "vent", then it fired and idled somewhat at 1500 rpm(very very rough), and I barely made it back home(belching black, very rich smelling smoke the whole time). I checked the o2 sensors in the exhaust manifolds and they are plugged in and working(is there possibly a missing o2 sensor after the converter, or is it only supposed to have the 2?), I also checked the fuel pressure when I changed the filter and it was right on. I don't think it's the ignition(cap,rotor,etc..) because it really didn't look that bad when I took it apart. It's driving me nuts.

Any help would be greatly appreciated, I just sold a exellent running TBI car to "upgrade" with the TPI--If I can't get it to work, I'll need to switch to a carb, and I really do not want to do that.

 

There is only one O2 sensor, in the driver's side exhaust manifold.

Your symptoms sound like a bad fuel injector. Did you check the plugs to see if any were wet with fuel?

You can also ohm the injectors while the engine is cold, and again when its hot. They should be around 15 ohms. Any less than 12 when hot and that's a bad one.

 

I looked at all the plugs I could get to and they pretty much were all wet/dark brown. How do you go about checking the ohms on the injectors, and do you check them while it's running or key on/not running?

Thanks for the help.

 

CTS? I'd check that first.........

 

Coolant Temp Sensor? I'll look at it but where is it and how do you test it?

 

It's one of the three on the front of the manifold. Can't remember which one it is right now.

 

.....Update.....
I checked the ohms of all injectors and got readings from .002(4 were .002-.006) to .014, so I would imagine that I found my problem. I ordered a new set this afternoon from John at FIC, we'll see what happens when they go in.

 

Those reading seem unlikely. You disconnected them first, right?

 

Yes, they were disconnected-I may have had my multimeter on the wrong scale(ie .014/.14/1.4/14) but John at FIC said it really didn't matter, it's more of a comparison test anyway. The low reading injectors are hanging open and letting the fuel drain into the cylinders and causing it to flood after it's turned off. That's why if I let it sit for a day, it will run okay for a bit (until the uncontrolled fuel richens it to the point of killing) because the fuel in the cylinders evaporates. As soon as I shut it off after any given time and try to start it within 3 hours or so it won't even fire because it's still flooded. The way I look at it, the injectors in the car are 17 years old-and the new ones are a much better design. It needed new ones no matter what.

 

yea what scale you use don't matter much.. just move the decimal point.. but an array of readings will tell you the condition of the elec coils of the injector. In our little club here we had an injector test day this summer. 1/2 the cars had at least 1 injector under 10 ohms.. all 30 members with multecs replaced them with FIC's bosch 3's// Jon gave us a group buy and threw in gasket sets. all the guys are tickled pink.. we all changed them the same weekend at a local lot we meet at. It was a fun day to see all those cars apart at once with all the guys pitching in. helping with all the installs. Not one leak. Just follow his instructions.

 

You can send money to my paypal account, same email address.


Glad you got it figured out.

 

I only figured it out with some help from my new friends.
I gotta get the new ones in yet, but I'm 99.9% sure that the stock injectors are toast.

 

If not, my guess is the diapharm in the fuel pressure regularo went south and has a split in it...

Check the vacuum line going to the FPR and see if it smeels like fuel.

If so, then check the dipstick, make sure you're not "making oil", and sitting behind a time bomb.

 

My car is doing the exact same thing except for the fact that I can't keep it running long enough to get a block down the road once it warms up. I have checked the CTS sensor I replaced it just incase The FPR seems to be just fine runing a constant 40PSI. RacerX79 please let me know your out come once you get the new injectors in

 

Well, got the new injectors in and it fired up and ran perfect for the 15 minute run-in period, sounded great, idled at 900-1000 rpm...perfect. Turned it off, and it started right up again and ran fine-it never did that before! I decided to take it for a small test ride around the block-I did several starts and stops and it would stay running great and doing everything like it should. Then I come to the last stop sign and it kills. IT WOULD'NT START AGAIN!! . I had to hold it to the floor to get it fired and limp it home sputtering and blowing black smoke out the back--the same exact thing it did before I did the injectors.

Now, why would it run great for 45 minutes and then take such a radical turn and barely run at all? It seems like it's gotta be something simple, any ideas at all? Or is all hope lost for the TPI....

Oh yea, one other thing. I can unhook the battery and let it sit for 5 minutes and hook it back up and it will fire up, but run very eradicaly from 1500-2500 rpm, and then not start back up.

 

If I were you id check all the simple things just to know for sure nothing is causing the ecm to revert back to running the car like crap after it sits for that period of time.Open up the throttle body and see if if gummed with a black film..my Iac was butt ugly covered in crap and gave bad readings.Some intake cleaner fixed that,depending of being maf or map..check air filters and vacumm lines,pvc's are working properly,check the spark plugs also,they wont fail in telling you exactly how the car is running based on the tips of the plugs..too rich or too lean.Think of anything you can clean or check that wont give a actuall trouble and you will find the lil culprit Im sure and be roasting tires in no time again.All my eradic problesm were from dumb things..loose lines,bad plugs,clogged ports,bad egr and pvc,old vacuum lines were dry and cracked.Keep us posted

 

Damn I was hoping that would fix it so I acould give it a shot on mine. I have changed plugs, cap, rotor, coil, CTS. I still need to do wires and O2 sensor. My car also sat for 3 or four years. The plugs I pulled were black and fouled out. car would hardly run at all. new plugs equaled idle for about five minutes till the car warmed up a bit then died. cap and rotor got me half a mile down the road pulled back in driveway and died had to push it back to the garage. the plgs last time I checked were slighty brown.

 

Okay, I went out and checked codes this morning and it has a couple(it wasn't giving codes before). I've got "15-Coolant temp sensor circuit open" and "43-ESC signaling for prolonged retard too long". I would imagine one might lead to the other so I'm going to try a new CTS sensor. We'll see....

 

While your at it,its easy to check the esc module under the cap of the distributor.Mine was all nicely green and corroded and would malfunction while hot but never gave me a code untill it stopped working completly so dont over look that aswell.As said before..the lil things are what bite ya in the ****..esc modules are cheap and easy to replace..and for the comfort of knowing its 100%..replace it too.Soon enough that motor wont have any excuse to act up and you will know the motor like the back of your hand if anything acts up.

When I thought I had a bad cts..turns out the connector was just faulty..not the cts itself so use a multimeter and check the sensor when you take it out too.It you take a torch or even run it under hot water for a lil while and then meter it and it gives a reading other than being an open circuit then check if the wires mayb be pinched etc.

Tedious I know but I had fun chasing my issues and when all dialed in the motor ran hard..and then i popped it when the trans died and over revved the motor :S

 

Turns out the knock sensor was broken, and the cts was the original one in the car. I put the new knock and cts sensors in and changed the plugs and it seems to be running fine. I took it for a 40 mile or so ride today and it ran great the whole time. I think the knock sensor may have been the main culprit the whole time, but the new injectors work sooo much better than the stock ones. Thanks for all the help guys!!

 

Ya I got mine fixed to well it seems to be good so far. Replaced the pick up coil and solenoid in the distributor and it runs like a champ now