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92 Bronco no start after engine swap

Projectjunkie

Whatever
Joined
May 19, 2020
Member Number
306
Messages
2,869
Loc
Tucson Az
It started and ran and sounded decent for 45 seconds, I was about to shut it off, add coolant, triple check everything anyways...

So after doing all that, it just cranks, I was running out of time, I didn't actually do a spark test, but now I'm thinking it's flooded

Timing, at this point, was set by verifying TDC comp and dropping the dist in

After attempting to start, there is a very loud rhythmic tapping from the engine, possibly the top, like a solenoid clacking for 30 seconds, an off chance, maybe a fuel line making a noise hydraulically?


The long boring background

The truck drove in on 4 cylinders, blown head gasket, and 3 of the injector pigtails eaten by rodents

Truck was originally a 5.0, somebody installed a 5.8 at some point, maybe from a van, as the fuel lines were a little wonky, and the rear lifting eye was gouging the firewall

He sourced a "ran when parked" 93? 5.8
I'm not sure how long it'd been sitting, or the condition of the injectors. The harness was completely different, so I cut out the injector pigtails and used the original harness

I'll be at the truck in 30 min and hoping for some suggestions when I get there.

Thanks
 
My guess on being flooded is due to a fuel smell, not popping off on ether, and I gave it a really long crank at the end there, and it was trying to fire



Likelihood of stuck injectors coming from a parted out unknown truck?
 
Still using that shitty TFI module ignition? Had issue with those liking to fail unexpectedly.
 
If it doesnt fire off ether, than you can rule out the injectors, for now.


I hate to be that guy, but really need to verify spark. Test the injectors/harness with a noid light. Then get back to us.
 
posford said:
Still using that shitty TFI module ignition? Had issue with those liking to fail unexpectedly.
Click to expand...
Ok, the tfi is the flat one on the side of the dist with the flat connector used later in that era, correct?


That's what the engine came with, I swapped the dist that out drive in with, it had a round pigtail coming out of it
 
Projectjunkie said:
Ok, the tfi is the flat one on the side of the dist with the flat connector used later in that era, correct?


That's what the engine came with, I swapped the dist that out drive in with, it had a round pigtail coming out of it
Click to expand...
Same had the module on the dizzy, some had a box on the inner fender. Been years since I've fucked with it so details are fuzzy.

arse_sidewards you got 2 cents?
 
TRINDU said:
If it doesnt fire off ether, than you can rule out the injectors, for now.


I hate to be that guy, but really need to verify spark. Test the injectors/harness with a noid light. Then get back to us.
Click to expand...
You're right, but towards the end of my 7 minute troubleshoot, I'm thinking injectors are sticking open, flooding cylinders, and ether wasn't helping

That's my leading theory, at the moment
 
Your mind is going 100mph isn't it.
Been there.

Have to take a step back, deep breath. Start with the basics. Have spark? Have fuel pressure?

Ignition coils used to go bad from just sitting too long. Completely unpredictable.

ran 45 seconds, fuel tank empty? Pump stop?

Bent push rod? I have had a couple 5.8 bend push rods after they had been sitting a while. No rhyme or reason.
 
Tiha said:
Bent push rod? I have had a couple 5.8 bend push rods after they had been sitting a while. No rhyme or reason.
Click to expand...
Would be consistent with the tapping sound wouldn't it?

For fuel pressure throw a tire pressure gauge on the schrader valve on the fuel rail
 
posford said:
Same had the module on the dizzy, some had a box on the inner fender. Been years since I've fucked with it so details are fuzzy.

arse_sidewards you got 2 cents?
Click to expand...
Modules usually fail intermittently when hot at first.

PIP/distributor sensor failure can give the same intermittent dying or running like shit when hot symptoms.

Anything 92+ should be new enough that it has the module on the fender. The fender modules basically never fail compared to the distributor mounted ones.

I agree that if it's not running or backfiring at you off ether you need to test spark.
 
Some clarification...


The tapping is with the engine off, after running

The coil, dist, harness is all components that the truck drove in on last week

The injectors, fuel rail, came with the engine that sat an unknown amount of time
 
Projectjunkie said:
You're right, but towards the end of my 7 minute troubleshoot, I'm thinking injectors are sticking open, flooding cylinders, and ether wasn't helping

That's my leading theory, at the moment
Click to expand...

I've never had a old gas injector stick open, I've had them clogged due to varnish though.

Pull a few plugs and that ought to decide your fuel theory.
 
posford
arse_sidewards
TRINDU

Base timing pointers?

I am also considering the balancer slipped, I'm not sure I cloud have been 30deg off. 180 sure, but I double checked it pointing to #1 after engaging the teeth, with the pointer on zero mark


Idling at 1200

FWIW, my obligation was to swap engine, tighten bolts, no leaks, not chase the million driveability issues these trucks are known for
 
Fuck looking at timing pointers and using lights. Let it idle until it warms up, pull the SPOUT connector, connect a vacuum gauge where the booster usually goes then advance the distributor until the vacuum reading stops going up then back it off a hair.

1200 isn't a bad cold idle. Most EEC-IV will idle fast until it warms up at which point it wants to be at 750 or so.
 
arse_sidewards said:
Fuck looking at timing pointers and using lights. Let it idle until it warms up, pull the SPOUT connector, connect a vacuum gauge where the booster usually goes then advance the distributor until the vacuum reading stops going up then back it off a hair.

1200 isn't a bad cold idle. Most EEC-IV will idle fast until it warms up at which point it wants to be at 750 or so.
Click to expand...
This, I've also done it by ear with okay results. My old duraspark shit wanted weird timing before I went HEI
 
arse_sidewards said:
Fuck looking at timing pointers and using lights. Let it idle until it warms up, pull the SPOUT connector, connect a vacuum gauge where the booster usually goes then advance the distributor until the vacuum reading stops going up then back it off a hair.

1200 isn't a bad cold idle. Most EEC-IV will idle fast until it warms up at which point it wants to be at 750 or so.
Click to expand...
Number one problem on a 302-351 swap is people fuck up the firing order. 302 non-HO is a different firing order than a 351W or 5.0HO. There is no way fix this on an EFI without either a cam swap, computer swap or a programming chip. Just swapping the wires will NOT work.

Ford trucks of that era are speed density batch fire injector systems (exc MAF SEFI in 94-96 Broncos and F150), and that means that four (4) of your injector events and four (4) of the O2 readings are going to be wrong per engine cycle.


Your base idle only increases in EEC-IV by 72 RPM until you hit 160°F - then decays to 0 RPM by 180°F. Base neutral idle on a 5.0L Mustang is 672 RPM - the trucks are not far off.

Base timing with the SPOUT unplugged is 10° BTDC.
 
FordFascist said:
Number one problem on a 302-351 swap is people fuck up the firing order. 302 non-HO is a different firing order than a 351W or 5.0HO. There is no way fix this on an EFI without either a cam swap, computer swap or a programming chip. Just swapping the wires will NOT work.

Ford trucks of that era are speed density batch fire injector systems (exc MAF SEFI in 94-96 Broncos and F150), and that means that four (4) of your injector events and four (4) of the O2 readings are going to be wrong per engine cycle.
Click to expand...
Sounds like a whole bunch of shit that's not a problem with a 300 :flipoff2:
 
Turned the distributor till it idled at 1000

Got it on the road, had decent power, didn't hear it ping, I'm washing my hands of it.

This is my 2nd favorite looking truck, right behind a 79 dent, but I just hate the electronics on these
Maybe someday I'll restore one and really geek out about how they work



Thanks for the help gentlemen
 
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