Rough cold start... any ideas
#1
Senior Member
Thread Starter
Join Date: Oct 2004
Location: Cleveland Ohio
Posts: 680
Likes: 0
Received 0 Likes
on
0 Posts
Car: Formula, a big red brick.
Engine: A Ford 351 Windsor... ?
Transmission: Dodge 727
Rough cold start... any ideas
It takes about 4-7 seconds of cranking before the motor starts, and when it does, it runs very poorly in open loop. Once warn, it runs decently.
The fuel pump primes the system. Tried 2 or 3 key on's but that didn't help. Does the 7747 need to see a minimum Oil pressure before pulsing the injecotrs on a cold start?? Just shooting for any possibilities here.
The fuel pump primes the system. Tried 2 or 3 key on's but that didn't help. Does the 7747 need to see a minimum Oil pressure before pulsing the injecotrs on a cold start?? Just shooting for any possibilities here.
#2
Supreme Member
iTrader: (2)
Join Date: Jan 2002
Location: Moorestown, NJ
Posts: 9,962
Likes: 0
Received 3 Likes
on
3 Posts
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
The 4 secs when cold is normal for tbi. Takes some time for the fuel to make its way down into the runners. Theres no minimum oil pressure needed. Once the engine turns and the ecm sees reference pulses, it fires the injectors. May want to check fuel pressure if it runs like crap untill closed loop. Could also be a tunign issue. Has it just started doing this?
Last edited by dimented24x7; 08-27-2005 at 11:42 PM.
#3
Senior Member
Thread Starter
Join Date: Oct 2004
Location: Cleveland Ohio
Posts: 680
Likes: 0
Received 0 Likes
on
0 Posts
Car: Formula, a big red brick.
Engine: A Ford 351 Windsor... ?
Transmission: Dodge 727
Done it since I've owned it. One of those things I grew sick with in the past few months. Love TBI's durability, not a fan of these things, among others. FP is about 20+lbs at the top of the line at prime up. I either don't know how, or can't read the pressure while the engine is running. I never really looked into it that much.
I was hoping it would be an indincitive problem concerning a possibly fualty MAP or Oil switch.
I was hoping it would be an indincitive problem concerning a possibly fualty MAP or Oil switch.
#4
Supreme Member
iTrader: (2)
Join Date: Jan 2002
Location: Moorestown, NJ
Posts: 9,962
Likes: 0
Received 3 Likes
on
3 Posts
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
20+ is way too much pressure. Should start off at 12 psi or so and remain there during run. Definatly want to check that. That could be alot of your problem there if your close to flooding out the motor.
#5
Senior Member
Thread Starter
Join Date: Oct 2004
Location: Cleveland Ohio
Posts: 680
Likes: 0
Received 0 Likes
on
0 Posts
Car: Formula, a big red brick.
Engine: A Ford 351 Windsor... ?
Transmission: Dodge 727
20lbs pressure at the line.... I disconnected the TB inlet line, and taped my pressure gauge into that. I would assume the regulator would take it down to the 12-14lbs, but the regulator wasn't connected since the TB wasn't connected. Sorry for not being more specific.
#6
Supreme Member
iTrader: (2)
Join Date: Jan 2002
Location: Moorestown, NJ
Posts: 9,962
Likes: 0
Received 3 Likes
on
3 Posts
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Thats the dead head pressure of the pump. You need to hook the pressure gauge up with the tbi connected.
#7
Supreme Member
iTrader: (2)
Join Date: Jan 2002
Location: Moorestown, NJ
Posts: 9,962
Likes: 0
Received 3 Likes
on
3 Posts
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
it uses a three way return style fuel pressure regulator. So the whole system needs to be hooked up as it would be normally. In other words, the gauge needs to be in line.
Trending Topics
#8
Senior Member
Thread Starter
Join Date: Oct 2004
Location: Cleveland Ohio
Posts: 680
Likes: 0
Received 0 Likes
on
0 Posts
Car: Formula, a big red brick.
Engine: A Ford 351 Windsor... ?
Transmission: Dodge 727
If you can point me in the direction of a reasonably priced gauge, or way of tapping my gauge into the system, I'd look into it. As of yet, I haven't found a T-fitting that I could throw either inline with the Inlet or outlet lines, that I could hook the gauge up too reasonably.
Prehaps I'm just looking in the wrong places.
Prehaps I'm just looking in the wrong places.
#9
Supreme Member
iTrader: (2)
Join Date: Jan 2002
Location: Moorestown, NJ
Posts: 9,962
Likes: 0
Received 3 Likes
on
3 Posts
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
There are specialty gauges available that hook inline. Like 50 bucks, through. Can also use a barbed t-fitting and jsut cut and clamp it in on the soft supply line.
Thread
Thread Starter
Forum
Replies
Last Post