what have I gotten myself into??

stangbanger67

Registered User
O.K. here we go. I'll start at the begining. I picked up a 89 cougar XR7. It was in pretty good shape and I picked it up pretty cheap, but it wasn't running very good. Hard starting, rough/wandering idle. I started w/ the basics- plugs and wires. No change. A friend let me borrow some parts from his car, (90 XR7) so I swapped the coil, module, and the computer. Still no difference. So I do a compression test. #3 cyl isn't holding so I tear it down and have the heads gone through, new fel pro gaskets, head bolts, timing chain, water pump. Then when i'm half way through putting it back together I find THIS WEBSITE and I get bit by the performance bug. MPII blower, MP plenum, MP 3 1/2" cai, 85mm TB, asp underdrives , 5% pulley, ported manifolds, 190lph fuel pump & 38lb injectors. Well as you might have guessed, I'm pretty excited. So I put it together-( very carefully) and the damn thing won't start. What do you think guys? CPS? Cam sensor?:( Its got spark and fuel. Just won't fire!!
 
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Automatic or 5speed? If Automatic, is the upshift light staying on while you ar cranking the engine? If so, problem with the crank shaft sensor.

I'd start with trying to pull codes. You may not get any but that is always the first place to try because it's simple.

Then I would check fuel pressure, to make sure you have pressure at the rail.

Then I would check the crank sensor and verify it is set to the proper gap. Without a crank signal the EEC will not even attempt to start the engine.

The link below is a walk through of testing the electronic ignition in general. It might help you test your components.

DIS Ignition System Testing
 
how about the starter? Perhaps you did everything right in the engine bay and the starter is just locked up or seized or somethin. Worth a check
 
If it has fuel and spark I'm not sure what more it would need. If it's the crank sensor, it won't spark. If it's the cam sensor, it could be sparking out of time. Disconnect the cam sensor and then try to start it.

If it doesn't start, turn the key off, and try again. Then if it doesn't start, turn the key off, and try again.

If the EEC can't see the cam sensor signal, it will try and guess when to fire. About one in 3 tries it will guess right and it should start.

If with the sensor disconnected it starts, but with the sensor connected it doesn't, that means your sensor is not positioned properly and it is giving the wrong information to the computer.
 
OK it has spark, so that rules out the crank sensor, right?? Ipulled the plug on the cam sensor but it still wont start. It pops like it wants to, but it won't. Cam sensor crapped out?? I also remember reading about a mod that had to be done to the 85mm t-body to get the proper tps voltage. could that be the problem??
 
The first and easiest thing to do is check for codes. If an electrical problem (sensor, wiring, etc) is bad enough to cause a no-start, it's likely it will set a code in the KOEO test. But it might not, so NO codes doesn't necessarily mean everything is OK electrically.

Also have you checked your compression? The reason I mention that I've heard the "popping" sound on another members car when the pushrods were too long and the valves weren't closing. It sounded really weird when cranking, kinda made a whooshing sound too.
 
TPS voltage should be .39 with the key on, engine off.

But if you are getting spark, then the computer is doing what it's supposed to. You're just not starting. Have you verified you have fuel? What is the pressure at the rail? Have you verified the Injectors are getting a signal to open? There could be a problem with the injector harness.

If you have spark, and fuel, it would have to at the very least back fire or something. How about have you tried sucking some fuel in through a vaccum line to see if it will fire that?

And rob has an idea too, something in the valve train not allowing compression to build. That would make it much less likely the engine will fire.
 
You might double or triple check the spark plug wiring. If you used one of the after market manuals, it seems like I remember one of them has the coil wiring diagram incorrect. If you disconnected the the cam sensor as mentioned above and tried to start it three or four times and it did not start, then the Cam sensor might not be bad. How did you establish that it is getting fuel? I ask because the crank sensor has 2 outputs; one goes to the DIS module and the other to the computer. If the computer does not get the correct signal it will not turn the injectors on correctly, but the signal to the DIS module can fire the plugs, thus causing the car to "fire" once in awhile but onot run. Kinda of a long shot......
 
Ok guys, please don't shoot me!!??!

I TRIPLE checked the firing order last night and well, guess what. I had the wires in the right place-ON THE COIL!- But when I ran them down to the motor, I set it up like a chevy's firing order!! The *** kickin line starts at the right.- I'm so ashamed! Guess I've been hangi'n around my buddy and his vette entirely to much latley. So I rearranged 'em- started right up. But it wandered at idle big time. from 500 to 2000 rpm. So I sprayed some starter fluid and found a huge leak on the lower intercooler tube. Tightend that up- purrs like a kitten! 21 on the vac. gauge. I'm syched! Just want to thank everyone who helped me out along the way. you guys are great.
 
this is FREAKIN GREAT!!!

HAHAHAHAHAHAHA I LOVE THIS THREAD!!!!!!! MADE ME FALL OFF MY SEAT LAUGHING!!!! its great how everyone here is so cool to help when we have problems, this is a great forum... but this thread should be saved in the archives or something!!!

by the way, awesome build man, bet it screams!!! you should get it dyno'd and tuned!!! get tons extra from that probably!!! would love to see a timeslip and maybe a pic of the beast... thanks, Adam
 
Well... That will do it. Good thing you found it. If anything , this helps reinforce why it's important you use logic and testing when figuring out what is wrong on the SC.

People get scared because they see a supercharger and the DIS ignition. But they forget it's a basic motor that needs the same basic things that any other internal combustion motor needs. It just gets some of them a different way.

Congrats... Maybe this is what some might call a teachable moment?
 
teachable moment....yes

Well, the motor is running now but I still have some things to do before I can dyno tune it / and see what she'll do. I gotta change the fuel pump. I have a 190 lph just gotta install it. Also have to get the exhaust addressed- Yes its stock-Yes I know thats not good for the mods I have. But it will be addressed soon. Until then I'll baby it. Spring time I'll have the gears installed, and go spank some honda punks!!!Oh yeah, I can't wait!!!:cool:
 
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