Fire from TBI

First I need to thank GTP Dad for his help with my oil in the radiator question. (I didn't know about the radiator cooling the tranny fluid.) Now here's what I've done & what's happening.
My GA is a '90, 2.5L, 4c, AT. I replaced the spark plug wires, plugs (changed these about a week before I tore everything else apart), valve cover gasket, thermostat gasket, air cleaner gasket & EGR gasket (EGR needs replaced but has to wait til I get more funds). I also scraped oil off everything I could reach. After I got her all back together she wouldn't start. (No surprise to me! Black cloud over my head gets bigger & darker over the last month.) So, I took off the air cleaner cover (this worked before), pumped the gas about 4 times and turned it over. Flames shot out from the TBI unit. I let it sit for a couple of minutes & turned her over again, without pumping the gas. Same thing!
Now the only thing I'm pumping is you guys for answers! I know I need to replace the tranny filter & gasket (the gasket is sticking out in a couple of places),the muffler is rusted off from the tail pipe & the EGR valve is needing to be replaced. I don't know what I did wrong or need to do to get my poor old girl running again. (At least long enough to get rid of her!)

I would double check the spark plug wire routing.

a bad EGR valve will make it run rough, but I'd say it was the plug wires. Unless its a quad 4, then i'd check the coils. Goul Luck \,,/

hi Penny,
welcome to AF.
yea 2.5L the Iron Duke, probably just crossed wires.

your firing order is 1-3-4-2

your pistons w/spark plugs go from left to right (looking into engine bay from the front of the vehicle) 1-2-3-4

trace your wires from coil to plug.

hope this helps,
chris
nrt racing

I was very careful not to mix the wires when I replaced them. I went from front to back, top to bottom replacing them. I don't see how I could have got them mixed up but I'll check it out anyway! My father-in-law suggested the choke might be getting stuck.
Before I did anything to her she had a stong fuel odor & went through about 1/4 tank in 30 or so miles! I had a hard time starting it after she'd been running a while, especially on hot days. Go to the store, be inside 10-15 min, come out & she didn't want to start. (Thats where I got the remove air cleaner lid.) I do remember she spit fire out once before when I was trying to get her going.
Also, it sounded kind of like an empty vaccumn after I got it running.
I'm checking your idea & Dads. Any more ideas in case neither works out? If any of you live in Oregon I'll chill the beer & BBQ the steaks if you'll come diagnose for me! :lol:

OK, I really don't think the choke is stuck (or the flappers in the TBI) as Pop suggested. I don't get the fuel odor unless I pump the crap out of the pedal.
Spark plug wires were another story! As I said I was darn careful the first time I put them on. After your suggestion I grabbed the old Haynes book & looked at their purdy pictures. I agree that in front of the valve cover they are from left to right (looking at the motor) 1,2,3,4. However on the back side, down where I can barely get my hand & can't see for crap, from top to bottom (according to the Haynes purdy picture) they are 1,4,2,3. The book says firing order is 1,3,4,2 just like you said. Doesn't make sense to me but thats what I did. That is not how they were though!
So now, I try to fire her off & she cranks away, with no flames. But...she doesn't fire off. Now what did I do ass backwards? I just need it to run so I can get back & forth to work! :banghead:

OK, I really don't think the choke is stuck (or the flappers in the TBI) as Pop suggested. I don't get the fuel odor unless I pump the crap out of the pedal.
Spark plug wires were another story! As I said I was darn careful the first time I put them on. After your suggestion I grabbed the old Haynes book & looked at their purdy pictures. I agree that in front of the valve cover they are from left to right (looking at the motor) 1,2,3,4. However on the back side, down where I can barely get my hand & can't see for crap, from top to bottom (according to the Haynes purdy picture) they are 1,4,2,3. The book says firing order is 1,3,4,2 just like you said. Doesn't make sense to me but thats what I did. That is not how they were though!
So now, I try to fire her off & she cranks away, with no flames. But...she doesn't fire off. Now what did I do ass backwards? I just need it to run so I can get back & forth to work! :banghead:


Penny, if you are quite sure the wires didn't come off in that order, put them back, but if it is possible they might have been crossed, leave them for the time being.
now get a hand mirror, or a dental mirror, something you could hold to the back of that firewall and actually "see" your coil packs. if they are the original ones from the GM factory, they will actually have numbers embossed on the tops of the coil.
I am pretty sure coil #1 will have the numbers for piston#1 & #4,
and coil #2 will have #2 and #3.
your firing order is 1-3-4-2, and the computer is actually controlling that, so all you need to insure is that (basically dot-to-dot) #1 coil goes to #1 piston/sparkplug, #2 to #2, #3 to #3, etc. (well you have a 4cyl, so only one more, but the same goes to an 8cylinder)
if these are correct, then you are correct, and it should fire (check fuel).
if the car has gas, and now you are sure it has spark, and it does NOT fire, then we have to look at other areas.

does the car have an EGR valve? if so, unplug the vacuum line to it, and try starting. if she fires, leave the EGR unplugged and drive it 'til you can replace it, or pull it off the engine and with the butt end of a screwdriver, knock the carbon out of it, and free up the diaphragm.
if no EGR, you may have what is called an IAC valve, similar to an EGR but computer controlled motor; still, two bolts to remove it from the engine and 'rap' it out of any filth and carbon build up.-----
scratch the IAC, I just went back and read your first post:
start with the EGR, if the plug wires are routed correctly, and EVERYTHING else, you scraped from the engine didn't include any loose electrical wires, she should fire... the other thing I might add:
with that mirror, look under the coil packs, there should be the control module, when you went to re-route the wires, make sure this didn't accidently get unplugged; otherwise, plenty of crank- no spark.
check your valve cover for tightness, and that no wires got pinched into it when you bolted her down (I wouldn't know to check these things, if we haven't already done this before).
the car was running prior to the maintenance, so it has to be something that was just recently done:
not T-stat, vavle covers would be vacuum leak, but not hnider start-up (unless what I stated earlier about wires),etc.
if she is still cranking, and not firing, have someone inside to crank the car, and you pull the #1 plug wire and rest it against ground (valve cover, shock tower, motor mount bolt, etc.), then have the person crank for you and watch- any spark? if so, you're good, if not,
maybe that control module (under the coils) just decided to go bad at the MOST inopportune time.
if she's still not running after this
email me or call;

chris
nrt racing
[email protected]
713.933.5773 (7A-10P central)

If Chiltons is my bible then you must be my god. I'mon it. Hopefully you're through with me!