Finally done! sort of

backtobirds

Registered User
I spent the summer putting together an engine, complete with SSM heads, Comp cam, MPX, long tubes, etc. It will start, luckily, because if I didn't start it by the time Fall quarter at OSU kicked off the car was going over the nearest cliff. So anyway it starts and is very loud even with mufflers, but it sound good. The only problem is that it won't stay running, pretty much starts then dies right off. I did have my chip reburned with my new MAF transfer and cam specs.

My thoughts are that the fuel pressure isn't right since I am using an adjustable regulator, and I haven't had a chance to set it with the car running. Has anybody ever noticed what their cranking pressure is?

My other thought is that the timing is off. I put the cam pickup in as best I could, but when the Ford procedure is to set the crank 26 degrees past #1 TDC and set the sensor housing in between 6 and 30 degrees of the face of the block, it doesn't seem very accurate to me. Anyone know any tricks or a better way to get it in there?

Hopefully I can get it running so as to avoid the cliff plan and make next year's shootout :)
 
Other option for setting your cam position sensor is to use the tool. Is nothing more than a cap that goes on the synchronizer, looks like a cam sensor. If you are too far off it could cause your running problem I would say since that is directly related to injector timing. Make sure that is correct before you mess around with the FPR. I'd say the minimum fuel pressure needed for the vehicle to start is 30psi. Most SFI vehicles need 30-45psi to run....
 
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I did use the tool, but the Ford install procedure leaves a lot of wiggle room. I'm gonna pick up a TDC locator tomorrow and do it again, as well as break out the timing light to double check. I know the car takes 39-45 psi with vacuum off the pressure regulator, but I'm having trouble getting it dialed in without the car running. Maybe I can borrow my buddie's Mustang to do it.
 
Does not have to be exact, as long as you have the Crank set at 26 degrees ATDC. That is much more important than the exact angle that the scynro is dropped in. Make sure to double check the crank position...Usually if it is slightly off it will bog on acceleration (Lack of injector timing). If its way off it wont start....I would also try putting a vacuum gauge on it to see if you have any leaks causing your non-idling issue. I know its difficult working on a car that wont idle, especially when you are by yourself...Hopefully your not working on it with any nearby cliffs.....could be too tempting
 
Haha, yeah, it is tempting. I'm gonna go pick up a piston stop and find TDC again. I just remembered I have to do it on the compression stroke, and the motor is together this time. What fun this is lol.
 
Well, I went over and played with it some more today. I got a piston stop and verified the cam sensor, it was dead on.

On the fuel pressure, it holds. What gets me is that it seems to run rich because I keep fowling the plugs, but if I turn it down it will eventually get to a point where it won't start.

Just for poops and grins I got a compression tester and put it on the car, it made 150 psi. When I crank it the boost gauge needle creeps into boost just a touch, then goes to 5-10 lbs when it starts and is in a low idle. It will idle for a few seconds, then die. and it doesn't stumble or sputter out, it just dies, like I turned the key off.

I guess my next step is to get some new plugs, start with a low fuel pressure and increase it until it runs, and open up the IAC bypass. I'll try that tomorrow.
 
FPR should be set to 39psi key on engine off.... thats it. You start toying with that and you might as well throw your chip out, because the assumption that has been made with your tune is your running at 39psi static fuel pressure. After that everything falls into place if its working properly.

1- Double check all your IC connections, vacuum lines and so on to ensure no vaccum leaks. Make sure the vacuum line to the AFPR is on.

2- Check all eletrical connections and grounds are in place.

3- Make sure the fuel pump is running when the engine is running.

4- Can you keep the car running by coaxing the throttle?

Frit
 
It won't stay running if I get on the throttle. The reason I messed with fuel pressure is that my tuner said the C&L transfer sheets are way off. I talked to himtoday and he said we will just have to tune it. I may be able to get it to him Saturday.
 
Well, I put new plugs in it today, but no luck. It still does the exact same thing. My tuner thinks my MAF transfer is way off (it IS a C&L), so I am supposed to meet with him Saturday to see if we can get it running.
 
Frit - what do you think about him trying to clock his MAF...? Or would that even be a factor in this case...
 
Got back from the tuner's shop. They can't figure it out either, but said it seems to be a timing issue. I agree. I checked the base timing with spout pulled, and it is at 6-8 degrees advance for the little bit the engine runs. Vacuum reads zero. I'm not exactly sure how an engine can idle with no vacuum, but it seems to. I double checked this with a gauge tool, not just the in-car gauge. Engine makes good compression, so the head gaskets should be good, and the valves aren't hung open. I plan on doing an intake gasket tomorrow and crossing my fingers. That could explain why it just shuts off, because the startup fuel tables are rich enough to account for the vacuum leak, but the normal tables aren't when it switches over. But of course that is one of a dozen possible reasons. I did have to lift the intake back up right after I installed it. I never had a problem doing that before, but who knows. It's the next thing to try.
 
Frit - what do you think about him trying to clock his MAF...? Or would that even be a factor in this case...

In this case its not a factor. The only time you would need to is if you have a sharp bend just before the MAF and your having trouble trying to dial in your MAF function.

Frit
 
I was told if you use the C&L transfer sheets you will need to adjust them accordingly as they can be way off. Not the same as throwing on a calibrated MAF for your particular injectors. Thats what the mustang guys have encountered. Can this be a MAF/injector issue?
 
Got back from the tuner's shop. They can't figure it out either, but said it seems to be a timing issue. I agree. I checked the base timing with spout pulled, and it is at 6-8 degrees advance for the little bit the engine runs. Vacuum reads zero. I'm not exactly sure how an engine can idle with no vacuum, but it seems to. I double checked this with a gauge tool, not just the in-car gauge. Engine makes good compression, so the head gaskets should be good, and the valves aren't hung open. I plan on doing an intake gasket tomorrow and crossing my fingers. That could explain why it just shuts off, because the startup fuel tables are rich enough to account for the vacuum leak, but the normal tables aren't when it switches over. But of course that is one of a dozen possible reasons. I did have to lift the intake back up right after I installed it. I never had a problem doing that before, but who knows. It's the next thing to try.

I thought so, but not after yesterday. I also put on a SCT Big Air 3000, per my tuners recommendation. I tore the top end down this afternoon. The intake bolts had backed out, and I could loosen them with one hand at the head end of the ratchet. I went ahead and replaced the gaskets since I was that far down. Good thing too, because they were soaked with fuel. I will check them tomorrow or Tuesday, and if they're good I'll put the rest of it on and go from there. If not, I'll get some threadlock and lock washers. Fingers crossed. If it was a vacuum leak, I may go back to the C&L. I do like it better.
 
I was told if you use the C&L transfer sheets you will need to adjust them accordingly as they can be way off. Not the same as throwing on a calibrated MAF for your particular injectors. Thats what the mustang guys have encountered. Can this be a MAF/injector issue?

I have yet to see any MAF out there that has a transfer sheet that was close, not just the C&L. I just did a car that had a older ProM and it was WAY out to space.

Frit
 
I just realized I haven't been on here for a while. Stupid school. Anyway, I replaced the intake gasket, and still no luck. So I decided to take off the front cover and verify the cam timing. It is perfect, but I did notice that the crank position sensor had some very light rub marks on it. Apparently the balancer vanes were just barely hitting. Not enough to move anything or send parts flying, but enough to leave a mark in the plastic. Also, I made the bracket out of plate steel, not making the connection that the pickup is magnetic. I made a new one out of aluminum, I'll see in a day or two if it works.
 
stock

You might consider putting as many stock parts on as possible (maf, injectors, tb, sc, tune) just to get it running and broken in. You don't really need it to idle perfectly to run it long enough to seat the rings (30 minutes).
 
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