Origanally posted in the Bronco fourm but no replies yet.

Here's the story....

Bronco runs fine then starts pinging under heavy load about 2 weeks ago. Now it will hesitate bad from a complete stop unless I ease into it. This happens after it warms up. Checked timing and it was 20 BTDC w/o the spout and I noticed that the dizzy bolt was loose. Set timing to 10 BTDC reconnected spout, computer adjusted timing to about 13 BTDC. I seem to remember when I put in a new dizzy the computer took it way over 20 after the spout was connected. Still hesitates as before BUT if I keep the spout out it runs like a champ no hesitation no ping, hell it runs better then ever.

Details....
New in the last 6 months or so.
EGR valve and position sensor
O2 sensor
Dizzy and ICM
Idle air control

MAP and TPI both test good and there are no codes.

Is my EEC going out so that it is having trouble setting the correct timing or heaven forbid the dreaded timing chain????

Also can I run it without the spout connected?? Is this an option if say I have to replace the timing chain and cannot get to it for a couple of months?

Update: running without spout for a couple of miles and no problems. Runs very smooth.

Thanks in advance


87 XLT, 302 EFI, C6, 184,000

 

Are you getting any codes?

Drop the initial to 6 and see how she runs with the spout connected...did you have the initial at 10 before your problems started and it ran fine? I know some can run more or less advance than others but if it ran fine at 10 before then my suggestion is only a bandaide and not a fix...haha...good luck...someone should know this one.

 

no codes, reading 11. When I changed out the dizzy a couple of months ago it was set to 10 BTDC. Seems that the dizzy got loose and it was at 20 BTDC when I started having problems. I will set to 6 tomorrow and see what happens.

Thanks

 

with the spout connected 20* is normal. but with spout removed it should read 8-10 btdc. when you installed that dizzy are you sure the #1piston was at tdc . it could be your dizzy is off a couple of teeth. what kinda dizzy did you go with, and what was wrong with the original. the spout needs to be connected while your driving. Could also be the tfi module located on the dizzy being bad

 

the dizzy was replaced due to a bad stator so I went and replaced everything, rebuilt dizzy w/ new stator, cap, wires and ICM/TFI (Autozone).

Timing was perfect after that. Set to 10 BTDC. After spout connected EEC took it to 20 or so and truck ran fine.

Dizzy was loose when I checked it after the problem started so I broke out the light and re-timed it. Still having problems when spout is connected. Without the spout connected it runs fine.

Perhaps the NEW ICM/TFI is bad??

Which sensor takes over the timing when the spout is connected?

Thanks

 

The ICM, you said it's an AZ part it's probably bad. You don't have to replace the dizzy to replace the stator, I actually went through 3 AZ stators, I refuse to use their igntion parts on anything but a GM now..... I got my new one at car quest, ran fine after that. But yes, the new ICM could be bad, as could the new stator.

 

napa is also a good parts house. but yes i bet your TFI module is bad. after you set the timing. unhook the pos battery cable and then depress the brake pedel. this will allow all the power to drain from the ecu. then after sitting for about 5 mins reconnect and drive for 30-45 mins in various conditions. this will allow the ecu to relearn the timing that you had just set. this to sometimes helps. but would still replace other parts as well.

 

PROBLEM SOLVED

Truck died today and had it towed home, no spark.

I took off the ICM and took it back for replacement still no spark with the new one. Also replaced the coil while I was under the hood. NO SPARK

ok, ok let me pull the dizzy...... Hey what's that little metal square stuck to the octane rod???? A magnet??? THE MAGNET FELL OUT OF IT'S HOLDER...DOH!!!

That was it, no magnet, no signal to PIP, no spark from coil, etc. etc....

Took it back to AZ for LLT replacement. All is well......at least until the next problem.

A BIG thanks to all who replied

 

see its that autozone crap dizzy. should not have done that. I would have asked for money back and went some place else for better hardware. but if this happens again i guess you at least know what to do. Pull the dizzy and start all over again.