Got fuel and spark, does not fire up

[SuperchargedSHOguy]

This is my personal 94 mtx with issues. Car has a 3.2 with shoshop stage 2 cams. Car has spark and fuel but does not fire up. I have tested all sensors multiple times and all grounds are present. Every wire has been tested out in the entire harness to make sure nothing went bad. Timing has been redone probably 5 times today. This car has not been fired up since the heads with cams have been installed- they were in a working car and I removed them today from my engine to make sure they did not have any bent valves from improper timing since I was told the engine is now interference with the cams.

Is there any special ways this needs to be timed to get it to fire up? I have called everyone I know who may know the answer but they are as perplexed as I am. A couple times I have had a backfire out the intake which leads me to believe the timing is off but everytime I check it is correct. I even pulled out a spare set of heads to check the cams and they are installed correctly in both heads.

Again, all sensors are working. All grounds are present. I'm trying to get it running for the FSHOC meet this Friday. The 3.2 is running all the correct 3.0 pieces as well.

 

[hawkeye18]

Just out of curiosity, how did you check for spark? Are you sure it's a strong spark? The DIS/Coil might have gone bad/weak. Also, make sure the fuel is spraying at the right time... fuel pump might have gone south... or the fuel itself might have gone bad!

 

[Storm-Chaser]

I presuming you've check fuel pressure at the shradder valve and spark at the plug-end of each plug wire. Did you test the injectors (ie. noid lights)? Have you pulled any plugs to see if they're showing signs of fouling (ie. excess gas)?

I had a somewhat similar issue with difficulty starting/occasional backfire through the intact while trying to start - and it was the coil.

 

[SuperchargedSHOguy]

Spark is very bright. Fuel pump is brand new. Fuel pressure is perfect. Injectors are firing and can be verified with a test light for pulse. Fuel is brand new 93 octane.

 

[sho_sc]

This is my personal 94 mtx with issues. Car has a 3.2 with shoshop stage 2 cams. Car has spark and fuel but does not fire up. I have tested all sensors multiple times and all grounds are present. Every wire has been tested out in the entire harness to make sure nothing went bad. Timing has been redone probably 5 times today. This car has not been fired up since the heads with cams have been installed- they were in a working car and I removed them today from my engine to make sure they did not have any bent valves from improper timing since I was told the engine is now interference with the cams.

Is there any special ways this needs to be timed to get it to fire up? I have called everyone I know who may know the answer but they are as perplexed as I am. A couple times I have had a backfire out the intake which leads me to believe the timing is off but everytime I check it is correct. I even pulled out a spare set of heads to check the cams and they are installed correctly in both heads.

Again, all sensors are working. All grounds are present. I'm trying to get it running for the FSHOC meet this Friday. The 3.2 is running all the correct 3.0 pieces as well.

What was done to the SHO prior to this happening?

 

[93rev2sev]

How many times have you checked the spark plug wireing order? It's super simple but it's all I can come up with.

Get a timing light to make sure the number one plug is fireing at(near) top dead center...

 

[Phoenix]

I may sound stupid (because you prolly have more experiance with SHOs then me) But Ive seen backfires with wires not hook up correctly (firering order)

Spray some gaz in the TB , if it tries to start (or might even start) , then its fuel related.

Is the braided ground behind the intake hooked up?

Is the DIS all 4 bolts tight (really , 3 bolts only makes car dont wanna start)

...

 

[hawkeye18]

omg, yeah, I didn't even think of that. Are you sure the wires are hooked up right? I know the chilton's has the order wrong. If you hook it up, it won't barely start, and if it does, it'll sound totally gnarly, only in a bad way (ask me how I know ). And yes, the wires are *supposed* to go on bass ackwards.

I think the order is... 1 2 3
.............................5 6 4

but don't quote me. Wait, yeah, do quote me. I'm looking at the 89 SHO engine book (the one I bought, ford! the one I bought!) and that's what it says. the 1 2 3 plugs are going to be on the right side, with 1 at the top.

Hope this helps...

 

[AREA 91]

Any codes?
When you checked the timing, was it just the intake cams? Did you check the exhaust cam sprockets?

 

[stangeater]

wow, I know you've checked it 5 times, but it sure seems like a timing issue? That sucks.

 

[SASHO91]

Guys, i'm sure Chris knows what he his doing, and can get (atleast ) the firing order down.


You know Chris, this sounds like an instance I had a few years back with a buddies ATX. We checked EVERYTHING, had fuel and spark just as you do. But still noda. So, we picked up the only thing left, the ECT. Fired right up.
But, that was atleast 3yrs ago, so i'm not 100% on that, but that's what I do recall about his car not starting.

You've tried the WOT while cranking right?

 

[SuperchargedSHOguy]

Prior to this the engine was fine. I've had the heads with the cams installed for some time and finally decided to install them on the engine (mistake). Now I wish I left it alone.

Plug wiring is correct, all grounds are hooked up and the DIS/crossover tube is bolted down to ensure the DIS is grounded.

The cams were installed the same way the stock ones are- again I did not install the cams, they came off a running car already installed in a set of heads, all I have done is put them side by side to a stock set of heads and both cams are in the identical places with the cam sprockets in the same place so I know they are installed correctly. I swear the timing is off but it just is not. It almost seems like it is pushing air through the intake from the engine but we pulled the intake and fuel rails, plugged the fuel rail holes and put our hands over each intake port and they all tried to suck our hands into the engine so I know this cannot be possible.

 

[sho_sc]

Prior to this the engine was fine. I've had the heads with the cams installed for some time and finally decided to install them on the engine (mistake). Now I wish I left it alone.

Plug wiring is correct, all grounds are hooked up and the DIS/crossover tube is bolted down to ensure the DIS is grounded.

The cams were installed the same way the stock ones are- again I did not install the cams, they came off a running car already installed in a set of heads, all I have done is put them side by side to a stock set of heads and both cams are in the identical places with the cam sprockets in the same place so I know they are installed correctly. I swear the timing is off but it just is not. It almost seems like it is pushing air through the intake from the engine but we pulled the intake and fuel rails, plugged the fuel rail holes and put our hands over each intake port and they all tried to suck our hands into the engine so I know this cannot be possible.

Two things come to mind. First, I've had plugs to fowl so bad from fuel flooding that the SHO just would not start, even after setting over night. Had to change plugs. Second, is it possible that the timing belt/is off a lot? Like 180 degress off?

 

[hawkeye18]

I've thought about this a lot, and to me, it seems that as long as you have all three marks lined up, the timing should be good regardless of how many times you've rotated the cams and/or crank - as long as the belt is off. Once you line the marks up, and you get the belt on - correctly - the timing should be fine.

I assume you've done the whole "hold the throttle down all the way to clear the engine" trick?

 

[SuperchargedSHOguy]

Two things come to mind. First, I've had plugs to fowl so bad from fuel flooding that the SHO just would not start, even after setting over night. Had to change plugs. Second, is it possible that the timing belt/is off a lot? Like 180 degress off?

I am thinking about getting a few new plugs tomorrow while I'm out since they have abour 20k on them but I doubt this is the problem. I have the intake off the engine again tonight and I may just slap on a set of stock heads and see what happens...

Stupid question, but I thought it was impossible to be 180 degrees off on these engines unless you don't line up the marks on the crank/cams- I was always told to just line up the marks. It makes me want to say the timing could be 180 off but how would it be 180 off? I have not had this happen before, this is not the first engine that I have had to retime or put one together, it is the first one with more agressive cams though...

And yes, I have done the "hail mary"- hold petal to the floor while cranking and pray for it to start, lol

 

[St Louis SHO]

Is the Timing belt on with the crank mark facing the front of the car? (I'm sorry, I kinda figure you're not this stupid, but have to ask.) And like Josh said, ECT is VERY VERY important.

- James

EDIT: Which way is the Engine wiring harness hooked up? White injector plugs to the rear?

 

[Storm-Chaser]

Define "very bright"

How did you measure fuel pressure? How did you validate the pressure regulator is working (pressure change with vacuum)? Did you pull the plugs (emphasis on plural) to verify they are getting fuel and none are fouling?

Did you test all the injectors? Did you use noid lights or something else in their place?

Fuel type and octane are irrelevant (within reason).

You need to find out what's going on inside the cylinders.

Spark is very bright. Fuel pump is brand new. Fuel pressure is perfect. Injectors are firing and can be verified with a test light for pulse. Fuel is brand new 93 octane.

 

[Mr Anonymous]

Do you have access to a compression tester/gauge? If so, that would probably be the next thing I'd check.

Also, set the motor to 0 deg. TDC, and pull the cam sensor. Where is the shutter wheel?

 

[TYSHO]

First, I've had plugs to fowl so bad from fuel flooding that the SHO just would not start, even after setting over night. Had to change plugs.

Exact thought, mine were shot with just a few thousand miles after some flooding. At times when the engine seemed like it was about to fire up or catch, it would cough back through the intake.


Edit: When my plugs fouled out, it was within the first two start attempts or so. I wouldn't rule them out that easily.

Good Luck on the fix, Chris.

 

[SuperchargedSHOguy]

White injector harness to the rear, black to the front- check. ECT changed out, check. I'll do the FP test again today and get ahold of a compression tester since the intake is back off and check the cam shutter wheel at TDC and update everything else tonite. Thanks for the help so far guys.