Car Finally Runs, But Runs Very, Very Crappy!

5

5.0 Mustang Man

Founding Member
Jun 21, 2002
234
0
0
New Mexico
#1
I finally got all my starting problems fixed and got to drive the car for the first time with my new Trick Flow Twisted Wedge heads, FRPP 1.6 Roller Rockers, Trick Flow Pushrods, Trick Flow Street Heat Intake, and C&L Downpipe to match my C&L 73mm MAF Sensor. The problem is, the car is running horrible. It is very eratic, wont idle at all, it just dies instantly after you put it in neutral, and it backfires pretty often. These are not extremely loud backfires but my friend was driving behind me tonight and he saw flames come out my exhaust every time it backfired. It also has the ocasional intake backfire. I have the fuel pressure set at 42 with the vaccume line off, timing has been moved all around and the higher it is, the better. I have new Autolite 3924 plugs, fairly new wires, and new cap/rotor. The mods are as follows:

Stock 91 5.0 HO Rotating Assembly, Stock Cam, TFS Twisted Wedge Heads, FRPP 1.6 RR's, TFS Street Heat Intake w/1" Phenolic Spacer, TFS Tall Valve Covers, BBK 70MM T/B, C&L 73MM Mass Air Sensor w/ Downpipe, FRPP 24* Injectors, Stock Fuel Pump, MSD Blaster Coil, FRPP 9MM Wires, ASP U/D Pullies, BBK Long Tubes, BBK O/R H Pipe, 2 Chamber Flows, And lots of drivetrain stuff, but that shouldnt matter :)

I know the stock fuel pump is not helping but I dont think it would make the car run this bad, and I know it should be ok with a stock cam, correct? If anyone has any ideas on what stuff I should check, it would be great. I really need to get it to atleast idel, it is rediculous!
 

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#2
is it idling high? check for vacuum leaks if it is. get a can of carb choke cleaner and spray it around your intake and TB gaskets, see if that affects your idle. did you tighten down your rockers right?

check those 2 things and see if either of those are the problem.
 
#5
I checked the plug wires twice and they are correct. I also adjusted the TPS to .996 so that should be good. It didn't help though. What else do I need to mess with? The farther I turn the timing, the better it will run but I have the distributor turned all the way until it is so far that the water neck blocks it from turning any farther. It is kind of scary with the timing like that but it doesnt ping. Please help me!!!!!! I have to get this thing running right!
 
#6
OK, just for ****s and grins, I hooked up the stock mass air meter calibrated for 19* injectors and the car will atleast stay running when I let off the gas. It still backfires somewhat but it seems much better and this is with a MAF meter that isn't calibrated for my 24* injectors. So, does this meen the sample tube in my C&L is bad or could the ford electronic module on the top be bad? I cant get it off to put my other one on right now because I need a tamperproof torx bt but I can try it tomorrow. Is there any hope that this could be one of my biggest problems? Also, when I did the head swap I completely eleminated the smog pump and lines. I have now noticed that there is one line missing from my vaccum cannister. It is not the one that runs up into the passenger side fender, I dont know where it went to, I think it went to the smog lines that were above the passenger side header. Is this line needed? Thanks for all the help.
 
#7
things to check...

see if the plugs are fouled
see if your wires are bad
see if your injectors are bad (one or more of them)
check your idle air bypass
make sure youre setting the timing with the spout connector out

just a few things for now :nice:
 
#9
Check the wires again, make sure you used the HO firing order! Try unplugging the MAF altogether and see if it runs any better. Also try turning the idle up, you will have to reset TPS after this. PULL CODES. Does it run any diffferent when cold? What do the plugs look like?
 
#11
Well the distributor wasn't removed ever and the Autolite 3924 plugs are brand new. I cant really mess with it tonight but I have lots of time to mess with it tomorrow. If I cant figure it out I might have to just take it to Mustang Muscle Perf. which is really close to my house, I just hope I don't have to because I'm broke!!!
 
#12
I just drove the car again and discovered something. I have been using a valve cover breather since before and after the heads/intake install. While I was driving, all of a sudden the car would actually try to idle. It was a high/surging idle, but atleast it didnt die. When I got back and opened the hood, I noticed the breather fell out of the fill tube and quite a bit of oil was all over that side of the engine. The motor was still running and I put the breather back on and the car instantly died. I pulled it off and started the car again and it stayed running, put the breather on, and it died. What does this mean? I'm totally stumped and starting to get really frustrated with this. Thanks for the help.
 
#13
You dont have a PCV valve? Have you hooked a vacuum guage to it? What does it read at idle? Can you turn up the idle and make it idle? Reset the TPS after adjusting the idle. Many people are having probs with the C&L stuff. put the stock air box and tube back on and see if that helps. there has to be a simple explaination for this. ttt.
 
#16
We finally got it to idle, or atleast somewhat idle and I'm able to leave the valve cover cap on now. When I push in the clutch, it slowly drops down in RPM's and finally will idle at about 800 RPM's but it is very rough. It doesnt die though. It has very small intake backfires every once in a wile on idle and it has very bad popping out the exhaust when driving. Is this a sign the the roller rockers are too tight or too loose? I thought I adjusted them right but maybe not. I can also hear what I think is either a header leak or ticking but only when the motor is revved and held at a certain rpm, not on idle. That is why I dont think it is a header gasket because it should do it on idle also. The timing seems best at about 16* with the spout out and 93 octane. There is no pinging.
 
#18
that sounds like un-metered air to me. you have a bad intake leak somewhere. make sure one of your gaskets didnt slip or you didnt warp your intake when you installed it. your car sounds like its running lean.
 
#19
I just got the upper intake off so I can adjust the roller rockers again and I could smell gas real bad when I took the intake off. The back four runners of the intake were damp with raw gas and the upper to lower gasket was soaked with gas on the last four runners. Why is there so much fuel on the back four runners not burning? What else should I do to stop this while I'm adjusting the rockers? Thanks.
 
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