Help me PLEASE 4.7 stroker wont idle or run right....

[shortxjdoug]

ok here it goes. Purchased a 4.7 stroker block running a 12w 258 crank and what looks to be the KB dished aluminum pistons. Unsure of cam specs but its similar to the xtreme 4x4 cam for these motors. Stock refurbished HO head and intake running 24lb ford injectors and controlled by factory renix junk. heres the issue im at right now.

will start and idle rough when revved you can hear it missing by way of lowered rpm but its running smooth and no smoke or any other ugly symptoms. once the tps is calibrated right it will idle very rough and very low, it will then begin to cycle idling very high and smooth to falling on its face and stumbling sometimes causing it to shut off, carb cleaner to check for vac leaks but cant find any weve replaced or checked everything we can but it still does the same thing over and over... ive got a big ride in 3 days and unless i can get this licked im gonna be out of a jeep for the biggest event of the year

 

[BlueCuda]

Mines not a renix but I had similiar problems and my distributor was not installed correctly. I installed it old school with the rotor pointing at the #1 cylinder and that wasn't right. I installed it per the service manual and it was great from then on.

 

[shortxjdoug]

Mines not a renix but I had similiar problems and my distributor was not installed correctly. I installed it old school with the rotor pointing at the #1 cylinder and that wasn't right. I installed it per the service manual and it was great from then on.

how does the service manual say to install it?



on another note the renix before was lacking a block coolant temp sensor... will this provide the idling symptoms im seeing in this motor now?

 

[gradon]

Sounds like the IAC is on the fritz, but could also be the MAP(try blowing out the vacuum tube going to it). Many strokers have issues with the distributor not being indexed correctly(due to being removed and not reinstalled correctly), so you'll want to double check that.

 

[shortxjdoug]

Sounds like the IAC is on the fritz, but could also be the MAP(try blowing out the vacuum tube going to it). Many strokers have issues with the distributor not being indexed correctly(due to being removed and not reinstalled correctly), so you'll want to double check that.

ive put 2 different IAC's in it and even run it with it unplugged and im getting the same idle (granted it doesnt cycle up and down because the computer cant use the IAC to keep the motor running) dizzy is in and indexed properly weve double checked all of that

 

[Boostwerks.com]

Have you checked the timing?

 

[old_man]

Does it run OK at higher RPMs? If it runs better at high RPMs, it sounds like the distributor indexing is off. Rotate the engine so that the crank points to about 14 degrees BTDC, then pull the distributor cap. The rotor should be pointing to the wire for #1 cylinder.

Also double check the firing order. The order is on the intake manifold.

 

[jcshaney]

i think i would defently hook up that coolant sesor would not be there if it was not needed
my 2cents

 

[shortxjdoug]

Have you checked the timing?

we have checked the timing everything lines up where it should be at TDC it just passing the 1 on dizzy... firing order is right it runss better but not well at higher rpm's

 

[Dr. Dyno]

Try this:

http://www.angelfire.com/my/fan/dist_index.html

 

[old_man]

Have you verified the wiring order of the injectors? Don't rely on the length of the wires, go by color code only.

If the engine sat for a while, run a can of BG44k through the gas. Injectors are notorious for gumming up if left to sit for a while. I added used but fairly new injectors when I built my stroker. It ran like crap until I put in a can and before I got home it was like getting a new engine. Don't waste your time or money on the cheap injector cleaners. BG44k is the best. Lucas can be used in a pinch but still isn't as good as BG44k.

 

[RedHeep]

Doug swapped out injectors at the campground friday night for stock ones and his stroker now runs pretty well. I think I even heard it idling at some point on saturday.

The black smoke from the extra fuel out the tailpipe went away too

 

[FlexdXJ]

Doug swapped out injectors at the campground friday night for stock ones and his stroker now runs pretty well. I think I even heard it idling at some point on saturday.

The black smoke from the extra fuel out the tailpipe went away too

That thing hauls ass now! 19lb injectors can work with a stroker!

 

[PacificEd]

He reindexed the distributor the night before and got it running, rich but running. The 19lb injectors leaned it back out. Ran good the whole weekend.