big mods, can't start it though!

mywhite89

Registered User
I finally have my car ready to run but it wont.:) It cranks and throws out some good flames out of the open headers but will not start. Heres what I have checked so far with no luck. Kind of long but this is what I need expanded on.

turn key halfway, fuel pressure up to 38lbs.
checked and have good spark at least to the number 1 and number 4 cylinders
cranks over fine, starter seems extra loud, don't know if that is normal
timing is set where it should be, we moved dist. gear to every position possible just in case and still no start. We did notice that it at least kind of fires when distributor is in its correct place:rolleyes:
Put a known to work DIS and cam sensor in to test that, no change.
Listened while cranking over engine looking for enormous vaccum leaks that may cause a run issue, none found.
Computer is out of a 90 5-speed never used in this car, fyi

Other things that come to mind:
While cranking the vaccum gauge does not move, I have seen it fluctuate slightly a couple times.
While cranking, bypass valve does not move at all.
Vehicle has no coolant in it, gotta fix the leak at the thermostat housing. The coolant temp sensor to the computer wont shut me down will it?
crank sensor is brand new motorcraft, lined up good, firm ride light shuts off after 5 seconds with key turned halfway and does not come on while cranking. Does this mean it is most definitely good?
New bhj balancer.

I'm still back to the drawing board on this one.
Possibilities that I have thought of

Huge vaccum leak that I'm not seeing, *noting the boost gauge with pretty well no movement while cranking.
Compression problem, I don't have a gauge but when we cranked it over with no #1 spark plug in, it blew out some pretty hard air on my hand. On my hand meter, it seemed pretty normal:rolleyes: . I had the engine bored .030 over with .030 over pistons. Installation seemed normal. I don't have the tools to check ring gaps though.

Everything is tight I ziptighted every small line and tighted my intercooler pipes nice and snug. The only possible vaccum leak that I can think of could be the inlet plenum to the blower. I never took the plenum apart from the blower to make sure magnum powers sealed them together.

Ok, I'm done rambling guys. Can you think of anything else that I am missing or should check? I think I've pretty well covered all the easy dumb possibilities. At this point I am officially lost!!:)

Chris
 
Last edited:
another thought, possible knock sensor keeping me from starting, or neutral safety switch?
 
Last edited:
I see you bored it out, did you do a valve job and machine the deck of block & heads? you may be in dire need for some shorter pushrods. How much did you machine off each?

My lifters needed a whole lot of cranking before they sat where they were spose to.

Just a thought.
 
Your injectors firing? Look at the plugs. Are they wet from fuel? If so, you are gonna need ta dry them out before if fires. If they are dry, it is firing properly OR, the pcm is not allowing them to fire. You sure you have a good crank sensor?

Chris
 
looks like u and me are having almost the same problems.

hope we figure something out, cuz im about stumped too.
 
Your injectors firing? Look at the plugs. Are they wet from fuel? If so, you are gonna need ta dry them out before if fires. If they are dry, it is firing properly OR, the pcm is not allowing them to fire. You sure you have a good crank sensor?

Chris[/QUOTE

Injectors are definitely working, plug that I pulled was nice and wet. The more I think about it, I am leaning towards a bad crank sensor. I want to find a way to test it, so I know for sure. Tomorrow I am going to try and start it one more time when everything is dry in the chambers but I don't think it will start.
 
The breeze coming out the plug hole proves nothing, a compression test would be an excellent place to start, its standard procedure when building a motor and "should" indicate that your valves are closeing. As for the wet plugs, just "floor it" while you crank it. Also look for an upshift light which i suppose means a bad crank sensor.
 
Last edited:
I see you bored it out, did you do a valve job and machine the deck of block & heads? you may be in dire need for some shorter pushrods. How much did you machine off each?

My lifters needed a whole lot of cranking before they sat where they were spose to.

Just a thought.


I did everything. I worked with Dave Dalke and we put a whole package together for the internal part of the engine. The heads were good, I had them checked. Larger valves, re-sleeved.

How much is a whole lot of cranking?
 
The breeze coming out the plug hole proves nothing, a compression test would be an excellent place to start, if you havint done one already.

I'm going to grab a compression gauge and check the number 1 cylinder. I'm confident every other is the same or very close. No upshift light while cranking, I beat your edit:) lol

Good point on making sure the valves are closed, guess I may need to check every one of them
 
Last edited:
I only spoke up because; When I was torqueing down my rockers I noticed that each one pushed the valve open just a little, even though they should have been shut. I knew that hydro-lifters were "tricky" so I pumped oil in with an old fuel pump and cranked it for a minute or two until I verified they were getting lots of oil, then did an excellent compression test. This might be your problem, it would certainly explain the lack of vacuum, keep in mind im no expert.


Hope this helps

Tyler
 
Last edited:
Does the boost gauge fluctuate while cranking normally? I havent driven the car in soo long, I'm not sure. It is a close fit from the valves to rockers but mine did not move when I tightened the rockers down. I paid close attention to that, but at this point I need to take that into consideration also.
 
Last edited:
Hey... r u sure the cam sensor is aligned properly? Here's a link: Cam sensor alignment Just a thought. Good luck!

I always just kinda popped it in, and it has worked for me before. I'll try that. I don't own the alignment tool though.

For an update I unplugged the crank sensor, and tried to start. Upshift light now stays on and vehicle does not even try to start at all. Plug it back in and vehicle sputters like it did before again. Cranks sensor must be doing its job.
 
I always just kinda popped it in, and it has worked for me before. I'll try that. I don't own the alignment tool though.

For an update I unplugged the crank sensor, and tried to start. Upshift light now stays on and vehicle does not even try to start at all. Plug it back in and vehicle sputters like it did before again. Cranks sensor must be doing its job.

Okay - I don't think u need the alignment tool itself... The 2nd post on that link shows how to do it without the alignment tool, even with the BHJ balancer you have.

On the early style setup like yours, the spark (and injector) timing come from a combination of the cam and crank sensors. So if the cam sensor is off, it could be firing the plugs waay out of time. Who knows? :cool:
 
I wish my engine looked like that! :D

Looks like the lowest horsepower supercoupe to me!:) lol, thanks though.

I just checked compression, none to to speak of my friend!! Gauge never moved. With no plug in their, you feel a poof of air but thats it.

I know the valves are NOT hitting the pistons or anything like that, but I'm trying to figure out where the heck I went wrong. I'm gonna start tearing it down. Guess I better take some pictures unless I am able to figure it out myself. Back to work.

I don't think it is possible to put the cam in 180 off is it?
 
Last edited:
Back
Top