86 GT needs help

[cptsnoopy]

Hi all,

Just picked up an 86GT 2.8 automatic. The price was right because a couple of years ago the owner shut it off to go into the store and when he tried to start it again, no dice. Since then it was worked on and left to sit for most of two years with no success in getting it running right. So, I think that this will be a good vehicle to learn about fuel injection and ECM's and such. Before I received the car they had replaced the ignition module, the pickup coil, the ECM and had the injectors serviced. Some time during all of that the fuel pump gave out. So when I got it, I changed the fuel pump and got the fuel sender working again. Then tried starting the car and all it would do is fire/misfire and would remain running if the accelerator was held about 1/4 throttle. But is was missing something terrible. Since the ignition module and pickup coil was replaced recently, I only installed another new ignition module and tested the pickup coil with an ohm meter. It checked good according to the haynes manual. So a new cap, rotor, wires, plugs and ignition coil were installed also. Result? Now the engine would not fire at all! I traced this back to the rotor of all things... The new one and old one look identical but putting the old one back in at least got the engine to fire a little... In the mean time, the injectors were sent in to be cleaned and tuned up again since the fuel had some contamination in it and I could not be sure it did not get to them. I broke down and installed a new pickup coil and now the car seems to run better but not drivable yet. Only able to get up to thirty miles an hour! For some reason, cylinders 1 and 3 are not firing. 2,4,5 and 6 all make the engine run rougher when the plug wire is pulled but pulling 1 and or 3 does nothing. After driving the car from its previous owners house to my house I finally got the ECM to store a code 33. It is the only code we have got so far. Is there any simple way to test the MAP before trying a new one? also is there any condition that would cause a false code 33? Can the O2 senser cause problems and not get a code? I still suspect there is something wrong with the ignition but I am running out of ideas. Oh, I forgot to mention that the EGR tube was cracked at the plenum mount and was welded back together. It seems to be holding ok. When we checked the vacuum it was around 15inches of merc. at idle at approx 1100 feet above sea level. does that seem ok? Next item to check is compression... Thanks for any and all suggestions

[cptsnoopy]

Compression test. dry test, ie no oil added to cyl. 5 compressions per cyl.
#1 133
#2 124
#3 128
#4 135
#5 133
#6 122

values are plus/minus 5 or so...

I changed the O2 sensor and the MAP sensor. no significant change in performance.

when I drove the car about 6 miles to bring it home, the cat became red hot and it smelled hotter than a normal cat. I think that is because cyl's 1 and 3 are not igniting and the unburnt fuel is going into the cat. Now I am wondering if the cat was not already clogged do to this happening before I got it.

Next test. unbolt the exaust from the y-pipe and see if it breathes better...

A question about the distributor...
the base plate on mine is slightly warped, it apears to be because it is aluminum and was pressed on the the dist body... this causes the dist cap to not sit just right, it can be rocked slightly and who knows if it is just right with the screws tight... has anyone else noticed this on their Fiero?

[cptsnoopy]

Ok, just fired it up with the exaust disconnected from the y-pipe with about a 3/8 inch gap. Huge improvement! Even though it is still missing at least 2 cylinders it has much better throttle response and higher revs... Now back to problem number one. Has anybody else experienced distributor problems even after replacing everything except the body itself? There is spark going to 1 and 3, it is just not as strong as the rest. I will try trading wires around to see if it follows the wires...

[pcv]

Replace the distributor shaft. Its bent and no good. You will have to transfer the pickup on to the new shaft. And also replace the egr tube. Its bendable and leak at the joints. It makes a huge difference to your vacuum.
All the luck to ya.

[cptsnoopy]

I just went out and played around with the ignition for several hours. I am now convinced that it is at least firing the plugs on all cylinders. I looked at the dist shaft when i changed the pickup coil and it was true and smooth. no noticable play when installed. I had checked the egr tube and it is holding vacuum when I plug one and I replaced the gaskets on it and the egr valve.

the good news is that i figured out what the real problem is... I used a 24" piece of 5/16" dowel to "listen" to the injectors on the rear bank. and was able to hear number 5 ticking away while numbers 1 and 3 were silent. I am going to pick up a noid light to verify pulse at the injector plug. I am pretty sure that there will be a pulse because when I sent the injectors in to be overhauled I checked the continuity of the injector wiring harness and it was good even while moving and bending the harness around.

if there is a pulse at the injector, I am wondering if I could "jumpstart" the thing if it is in slight bind. I don't know how much it would take to do that. I'll report back... thanks for the suggestions

[cptsnoopy]

Update:

I welded in a new cat. Just need to install the exaust... I messed with the injectors. I don't have a way to check flow but that was supposed to be done three weeks ago when I sent them in to be serviced. Here are the notes:

Cyl___ohms__amps___volts
_1____11.5___4.8____12.0___completely silent, not working
_2____11.8___4.8____12.0___ticking smoothly, working
_3____11.8___4.8____12.0___very faint noise, not working
_4_____8.6___6.5____12.0___ticking smoothly, working
_5____11.5___6.1____12.0___ticking smoothly, working
_6____11.8___4.6____12.0___ticking smoothly, working

I was supprised that the resistance and amp draw were normal on the ones that are not working but the lower resistance #4 is working fine. I guess it is time to replace them all...

Do these values seem normal for an engine with 99K miles?

It looks like this car had four different problems, at least one problem caused by an earlier problem.

1) Bad ignition
2) Bad injectors
3) Bad Cat
4) Bad fuel pump (we think it got bad do to the car sitting with less than a quarter tank of gas for about 18 months in the AZ heat.)

No wonder I got the car for free... :-)
I'll only have about $1000 into it just to have it running right and then whatever it takes to get a nice repaint and interior. whew....

[cptsnoopy]

good news!, six brand new "standard" brand injectors and now it runs...