Help me get this car running good!

[Crazyhorse 21]

fuel psi is 32 psi, i just checked it.

 

IIRC most EFI systems like more pressure, the SEFI 5.8 in my bronco is running in the low 40's with the engine off (stock mustang 5.0 is supposed to be 39PSI). If the fuel pressure is too low it could cause the issues you're having. Is that 32 static (engine off) or at idle, or? With the vacuum hooked to the fuel pressure regulator it will run full pressure with the engine off (no vacuum), and full throttle (also no vacuum). At idle the manifold vacuum lowers the spring pressure on the diaphram and drops the fuel pressure. At idle, with 18" of manifold vacuum you should have 30PSI. I'll let you know if I come up with anything else.

[bnickel 10,004]

actually even mildly built 5.0's like to have around 40-45psi, i noted that above already. i suspect that this could be at least part of the issue, especially if the compression is as high as i think it i, more fuel pressure=less detonation problems to some degree and if the engine is detonating then the computer could be pulling timing out as well compounding the problem

[Trinitys 134]

that was at idle, i'll check the instructions on setting it iirc there was something special about setting the pressure and the vaccuum line going to it.

[Trinitys 134]

Before I start….this is long, I’m sorry!!!

Okay, I worked on the car this weekend; I think I got it a little better. It still has poor power and feels like to me that it’s not firing on all 8 and has poor idle quality. I also have a brake issue that I will be addressing shortly after this is figured out.

I started out by pulling the distributor to check the gear to make sure it’s in good shape as suggested.

I stabbed the distributor and set base timing as follows

Unplugged the spout

I put the motor on TDC #1. Verified #1 by pulling #1 plug and checking.

I have the cap marked for TDC and 10 Deg BTDC.

I rotated the engine by hand to 10 deg BTDC, I have an aftermarket damper that is very easy to read.

Then I pulled the wire from #1 and put a screw driver in it. Put the ignition to the on position. Rotated the distributor and held the screw driver close to a ground and as soon as it fired, I stopped rotating the distributor. Tightened the hold down.

Started the car.

Checked fuel psi and it was about 32. Unplugged the vacuum line and plugged the line. I slowly readjusted to 40 PSI, tightened the locknut. In the instructions it doesn’t say to reconnect the vacuum line, so I left it off and plugged. It didn’t seem to make a difference if it was plugged in or not.

 

I didn’t really check idle speed because I think my tach-dwell is broke or seriously in question…..I dropped it. it seems to be high enough when warm. So I never unplugged the IAC for any reason.

 

Then I unplugged the battery for 30 minutes or and restarted the car. It starts right up and idles roughly when warm and does not stall out like in the video.

I took it down the street to see how it would run and it is still pretty bad still.

 

Here is the list of stuff which, in my opinion could be off or wrong based on information I’ve gathered in the last week for several sources.

 

As suggected by others

 

Bad head/piston/cam combo. Compression is too high. I personally don’t know how to calculate my compression but did go over all the specs with the machinist when I was putting the combination together. My goal was 10/10.5-1.

 

Wrong plugs for my combination. Once again, I don’t know how to figure out which would be best for what I have. I also have not changed my plugs since I’ve built this motor, remember this motor has maybe 50 miles on it.

Incorrect base timing, it is 10 DEG BTDC right now.

I flushed the fuel line for about a minute before I connected everything up but could I have put foreign material into the injectors? I have an Aeromotive 10 micron post filter for the system.

 

 

Possible vacuum leak but I’ve looked and felt and sprayed wd40 and can’t seem to find much. I can’t really reach behind the intake, it’s pretty tight. Is there a way to check? How do I do a smoke test as someone suggested?

 

 

Improper valve seat sealing. I bought the heads from a friend and did not lap the valve in. could these maybe be bad valve/seat contact? How would I check?

 

 

Misadjusted rocker arms? I’ve never had aftermarket heads on any of my cars, everything was stock before. I now have Comp Cams adjustable rockers. I followed the directions to a “Tâ€â€¦.actually these are the ones I used….. “Adjusting Hydraulic Lifters for Proper Preload†http://cranecams.com/?show=techarticle&id=2

After I built the motor, I printed this out, removed all the plugs from the motor so it would be easier to rotate and did each cylinder just as the link suggests. I would like to think I did this correctly but how do you know you got it exactly right, you relying on the feel of the push rod for your adjustment.

 

If you've got this far, thanks for taking the time, please give me your 2 cents.

[69fastback393 0]

you might try setting the valves @ 0 lash. without the extra 1/2 to 1 turn

[bnickel 10,004]

the way i've always adjusted rockers is take the valve cover off and start the engine and back them off one at a time until they just start to tick, then tighten the nuts about 1/2 turn and lock them down. you'll need some rocker clips to do this unless you don't mind getting oil everywhere. i'm guessing your heads use the small plugs and not the large plugs like the 69 windsors used stock, if so just get a set of plugs for a 93 cobra application and that should get you in the ballpark, the you can adjust the heat range up or down from there.

 

another way to check for a vacuum leak would be to use a propane torch, tuen the gas on BUT DO NOT LIGHT IT, then slowly move the torch around the intake, injectors, throttle body etc, if the idle changes at all you've found your leak. it sounds like you your timing pretty close but i would go ahead and check it with a timing light just to be sure. i would also back the timing down to around 4-6 degrees instead of 10 because of the unknown compression ratio, at least for now anyway, let's get it running ok first then we can start playing with the timing.

 

when you took for the test drive could you hear any pinging at all or is too loud to really tell? also do you know what octane gas you're using right now? you need to be using at least 91-92 octane with that much compression and honestly you really should have aluminum heads with that much compression but i think we should be able to get it running ok without them for now.

[Trinitys 134]

Rocker clips? Not sure what you’re saying here. I could do it with the covers off and car running but I’d prefer not to.

Yep, small plugs....I’ll get a set on the way home from work, not real sure what’s in there now, can't remember that far back

I guess I’ll pick up a timing light tomorrow too, and barrow a torch from work.

No my exhaust is pretty loud so no nada on the pinging. I think that maybe in the future I may go with a head that has a larger chamber to bring down the C/R slightly. I would really like to have it around 10-10.5.

You know I have an extra room here at the house....feel like taking a road trip?? I’ll come get you!!!:ph34r:

[bnickel 10,004]

actually they are more apporpriately called rocker arm oil deflector clips and they are specifically for adjusting the rockers with the valve covers off.

 

i modified an old steel valve cover by cutting it open and bending the uper edge so that it made it's own deflector. cut it on the lower end and both sides and bent the resulting flap up and then back down 90 degrees in the center of the "flap". i won't be doing that again though, let me tell ya valve covers are tougher than they look. you can get the rocker clips from any online speed shop like summit or jegs.

 

http://store.summitracing.com/partdetail.asp?autofilter=1∂=MRG%2D1015&N=700+115&autoview=sku

[69BossMach1 10]

My 2 cents:

CR, Distributor gear, and cam are all fine. NO problem there. I've run that cam and 11.5 to 1 CR for years in a 302 with stock heads. This motor will actually be a strong mid-range RPM running SOB once you get the bugs ironed out.

Fuel pressure. you need more. 45 psi minimum.

Distributor and timing. Don't guess at timing the engine like that. Get a timing gun NOW. Set your base timing to 8 degrees BTDC. Make sure you are by-passing the electronic advance on the distributor and computer, if they have one. I dont use Mallory for anything so I'm not sure if there is a bypass on this model or not. One of the other guys on here might know for sure.

Make SURE you have the correct timing pointer for your Cam / Balancer combo.

What size of gas line is feeding your pump/ press. regulator, and fuel rail?

Test or swap out the coil, even if it's barrowed.

Back all of your rockers off 3/4 of a turn, even if they tick, to verify you don't have them overtightened.... alot of header noise in your video. Sounds like an exhaust valve might be too tight.

[bnickel 10,004]

My 2 cents:

CR, Distributor gear, and cam are all fine. NO problem there. I've run that cam and 11.5 to 1 CR for years in a 302 with stock heads. This motor will actually be a strong mid-range RPM running SOB once you get the bugs ironed out.

Fuel pressure. you need more. 45 psi minimum.

Distributor and timing. Don't guess at timing the engine like that. Get a timing gun NOW. Set your base timing to 8 degrees BTDC. Make sure you are by-passing the electronic advance on the distributor and computer, if they have one. I dont use Mallory for anything so I'm not sure if there is a bypass on this model or not. One of the other guys on here might know for sure.

Make SURE you have the correct timing pointer for your Cam / Balancer combo.

What size of gas line is feeding your pump/ press. regulator, and fuel rail?

Test or swap out the coil, even if it's barrowed.

Back all of your rockers off 3/4 of a turn, even if they tick, to verify you don't have them overtightened.... alot of header noise in your video. Sounds like an exhaust valve might be too tight.

 

 

he's already verified the dizzt gears is ok but your suggestion that it is ok without verifying whether he has the correct gear or not is a big no-no IMHO. the dizzy he has is for an efi/roller cam motor and he has a flat tappet cam in a pre roller 351w block. if for some reason that dizzy had the incorrect gear for a flat tappet cam it wouldn't take long for it to destroy the camshaft. when in doubt always verify. also 11.5:1 with iron heads can be done but it's not going to happen with an EEC-IV EFI motor because the computer will have fits. 10:1 or 10.5:1 with iron heads is really pushing the limit even with 93 octane fuel. in fact i'm still not sure that isn't most of his problem right now.