North American Turbocoupe Organization



TC 88 doesn't fire, no start
EricVH Offline
Member
#1
ok, so about a week ago, Something Bad happened, and now my car won't start. The starter turns, the fuel pump primes, but it doesn't seem to fire at all.

Here's my trouble-shooting path:
1) After the Bad Thing happened, the engine still would start and run, so I thought maybe I had a timing problem -- I just replaced the timing belt a couple months ago. With SPOUT out and a timing light on cyl 1, timing is 10 deg BTDC.

2) I thought maybe it was only firing on 3 cylinders, so I shut off the engine and pulled the #1 plug wire off the distributor, to see if it made a difference. After that, the engine never fired again, even after replacing the wire....

3) I came to NATO, and went through the "Diagnosing a 'no start' condition" in the FAQ. Results:
- a spark plug connected to the coil or to end of the #1 spark plug wire gives a spark
- the fuel pump runs for a few seconds at key-on
- #1 injector red wire has +12V whenever key is on
- test lamp on #1 injector gnd flashes during cranking

I didn't check the fuel pressure, mostly because I couldn't easily get the cap on the schrader valve off. But I don't really want to spray fuel everywhere, and I don't think that's really the problem.... (Not sure why not, because everything else seems ok.)

So what else could it be?

A couple other points on recent service:
- Back in May 2012 I changed the fuel pump -- FPF019 from Auto Performance Engineering.

- When I changed the timing belt, I foolishly started it late in the evening, outside, on the last day before it got really cold last fall, and couldn't finish that day. So it sat in the snow for a couple months with the hood not quite latched all the way (cuz I leave my tools on top of the radiator) and the front cover removed, until it warmed up enough for me to finish.

- About a month ago, after finishing the timing belt job, the alternator failed and I got it rebuilt. (Interesting side note -- just before it really failed, it would only charge after goosing the engine speed above 2000 rpm. The rebuilt one starts charging right after engine start.)

- And finally, since I changed the timing belt and corrected what I think was previously horrible timing, I thought that maybe I could go back to running 87 octane fuel. So the tank of gas it's running now is the first time it's had less than 89 in several years.

And, for background, here's What Happened:
I had just pulled out of the parking lot, everything fine, and was stopped at a stop light. I went to take off, and when I let the clutch out I thought maybe I'd popped it to fast, since I was trying to take off. But right after that the engine began running...rough.

I can't quite put my finger on it, but it was sort of missing. The clutch was making more noise, but it's had a squeaky bearing for a long time, and I'm not sure if the bearing suddenly got worse or it was just making more noise because of a rough engine. Pushing the clutch in quiets it down.

Everything seemed ok if I went about 30 mph in 3rd gear, but faster or slower, or a different gear, and it was rough. It stalled once, but I got it restarted. Idle sounded rough, until I concentrated on it, and then it seemed ok. I pulled into a parking lot and checked under the hood, and everything seemed fine, and the engine sounded fine then. Get back in the car, though, and it was...rough. If I stepped on the accelerator, it would make boost. (I didn't push it past 10 psi but the turbo sounded ok.)

It stalled again when I pulled into my destination parking spot, but restarted ok when I left, and I made it home, no change in performance. I parked it for a few days, and then started my troubleshooting, above....

Where do I look next??
stock (mostly) '88 TC, slowly deteriorating....
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Pete D Offline
Administrator
#2
1. Bad Thing. How hard were you on it starting up

2&3. The car has not started since #1, correct?

A. was the spark a strong, blue spark? If so that is good.
That tells use the spark system is good ( doesn't mean timing
is correct.

b. fuel pump is suppose to run briefly when key is ON, to prime
the system.
c. Red wire always hot, the EEC grounds the circuit to fire the injector(s)

Make sure the cam is in time, then the ignition timing. Then
I think you need to check the fuel system. The engine needs air, spark and fuel. It appears you have air and spark. Why won't the cap some off the schrader valve? Once the cap is off, run the fuel system diagnostics; http://turbotbird.com/techinfo/Fuel_Syst...ostics.htm
Pete Dunham


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EricVH Offline
Member
#3
>> How hard were you on it starting up
You mean when I was taking off from the stop light? Not very. I was probably into the pedal all the way, but only about 2000 rpm. I don't think the clutch was all the way engaged even when It Happened.

>> The car has not started since #1, correct?
After It Happened, the car sat for a few days, and then started fine a couple times. That's when I checked the timing. Right after that is when I pulled the spark plug wire, and it has not started since then.

>> was the spark a strong, blue spark?
It was blue. It wasn't as strong as I was expecting, but it was kinda sunny yesterday, so I'm not sure if that was a factor.

>> Make sure the cam is in time, then the ignition timing.
Hmm. That makes it sound like I need to take the front cover off again.... With the camshaft lined up to TDC1, the distributor rotor is a few degrees clockwise of where I think the #1 terminal on the cap is. (I wish there were better markings!) So, maybe my timing "correction" when I changed the belt actually made it worse?

>>Why won't the cap come off the schrader valve?
Probably because it's been on there for 25+ years without ever being taken off.

Thanks for your help!
-Eric
stock (mostly) '88 TC, slowly deteriorating....
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Pete D Offline
Administrator
#4
No, you don't have to take the front cover off to check the cam. You do have pry out the black, rubber/plastic plug to see the timing marks for the cam. See this article http://turbotbird.com/techinfo/CamTiming...t%20Up.htm

Go down to step 4 & 5 and read them, then and see the diagram between 4 & 5.

See the picture right after step 9-A. Shows the dist cap and where #1 should be.
Pete Dunham


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EricVH Offline
Member
#5
ok. It suddenly started raining, so I guess I'll have to take a look at this tomorrow....

thanks again!
stock (mostly) '88 TC, slowly deteriorating....
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EricVH Offline
Member
#6
Good news and bad news --

Today I checked the fuel pressure and the cam/crank alignment.

Fuel pressure after prime and during cranking was between 40 and 45 psi. After cranking, when the engine was stopped, pressure held at 40 psi for several minutes. (I'd love to continue with step 7 in the "fuel system diagnostics" faq, but I can't get the engine started....)

When the crank pulley TDC mark is at TDC, the camshaft mark is between the 3 marks on the back cover (pointing pretty much at the middle one).

The bad news, of course, is that the engine still doesn't start, or even give a hint of firing.

So:
- the fuel pressure is right
- the timing is right
- a test light flashes when connected to the injector connector, so the injectors are being fired
- a spark plug connected to the #1 plug wire sparks, so they're being fired

Is there a good way to test the strength of the spark? That's the only other thing I can think of that I can repair that doesn't start with "Remove the engine from the vehicle (refer to section 21-05)." I guess I can test compression....

I still don't understand what could have happened. The engine was running fine until I let the clutch out to take off at a stop light; and even though it ran rough after that, it would still start fine until I removed the #1 plug wire from the distributor.
stock (mostly) '88 TC, slowly deteriorating....
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