1. Engine started running really bad with no power. He made it home, barely.
2. Engine would idle fast but die when accelerator pushed. Engine making lots of noise like it was only running on 3 or 4 cylinders.
3. Next day engine cranked right up but when idle decreased, engine died. Later same day, engine again cranked but would only run at high rpms, still sounded like it was running on 3 or 4 cylinders, with another cylinder or cylinders trying to fire every few seconds. Now engine will not start at all.
4. He found the fuel filter really dirty and replaced it. Still won't start.
5. We found several vacuum lines open where the previous owners had removed some of the emission stuff. Plugged all of them. Still no start.
6. Checked the fuel pump by jumping the plug and it runs and stops as the jumper is connected and removed. Pushed the schraeder valve while fuel pump running and seems to be plenty of fuel.
7. When ignition switch is first turned on, fuel pump is heard to run for a few seconds. Push schraeder valve and gas squirts for a couple of seconds, but fuel pump does not start again. Fuel pump will not start until ignition switch is turned off and on again.
8. Turned ignition switch on and cranked engine while checking voltage at fuel injectors. No voltage with digital meter.
9. Checked all sensors and all seem to be good..

Any suggestions at this time will be greatly appreciated. We have been on this problem for 4 days now.
Jim

 

I forgot to include a few things in the above post. It is a 89 with a 302. I just tried to crank the engine again. It acts like it is trying to start on a couple of cylinders, but never does.
I am going to pull the upper intake off tomorrow and pull the injectors. If anyone else has any suggestions, they would be appreciated.

 

Before you go tearing apart the engine, test a few things.

First is fuel pressure. A fuel pressure gauge is like $30. Test it, and then you remove all uncertainty.

Second is spark. It could be a bad coil - test it according to a Haynes manual (best $15 you'll ever spend)

Third - check your timing. It also sounds like the engine may have jumped time.

If your injectors aren't getting the correct voltage, then it's not the fault of the injectors. It could also be a problem with the PCM (computer).

Good luck, and keep us posted. Just an FYI, there is also a Bronco forum here on FTE.

 

andym,
Thanks for taking the time to reply. I too thought it may have jumped time. We rotated the #1 cylinder to TDC on the compression stroke and the rotor was pointing at the #1 sparkplug wire.
I also checked the timing with a timing light one of the few times that the engine would start. It was correct, but jumping around. I thought at the time that it was because the engine was running so bad. Now I wonder if the timing chain is stretched really bad. I will use a pull bar to turn the engine and see how much play is in the chain.
I checked the spark by using a screwdriver in the plug wire and letting the fire jump to ground. It would jump about 1/2 to 3/4 of an inch so I think it is good, even though it is not quite as blue as I have seen other TFI coils produce.
We pulled all the plugs and they are as expected, sooty. The first time we pulled them they seemed to be wet. The second time a day later, they are dry.
I'm not sure how to check the voltage at the fuel injectors, so I am not sure if that check that I did is telling us anything. Like I said in an earlier post, it does try to "catch" when starting on what sounds like a couple of cylinders.
The fuel filter was completly clogged so I think the injectors may have a lot of gook on them.
I'm at a loss except to pull the injectors and clean and check them. I will get a fuel pressure gauge as you suggested. I will check the fuel pressure before I pull the injectors.
Again,
Thanks

 

If the timing mark is bouncing around, then you're probably right about the chain being stretched out. The gears themselves might be worn as well.

First things first, though. Fix the timing problem, then see how things run. That may well be your whole problem, and you'll never need to pull the injectors or the manifold.

It sounds like your coil is good, but it never hurts to check the voltage just to be sure.

 

Ok, the timing is computer controlled there is a little plastic plug in a "spout" coming off the distributor harness, unplug it this will bypass the computers control on the timing see if it runs. If so start at the ignition module on the distributor and then move to the coil, or pickup in the distributor.

 

Thanks for the help. I pulled the little plug to take the timing off the computer and the engine still won't start. I'll know more tomorrow when I put a pull bar on the crank and see how far the engine turns before the rotor moves. I am open to any suggestions for checks. I don't want to pull the upper intake and all unless I have too. That center bolt on the inside of the upper intake looks like a bear to get to.

 

I think I would still replace the ignition contol module (mounted to the distibutor) it;s only ~$20.

 

"4. He found the fuel filter really dirty and replaced it. Still won't start" and "8. Turned ignition switch on and cranked engine while checking voltage at fuel injectors. No voltage with digital meter"
some dirt could have gotten to the injectors and cloged them. that may have caused the moters to burn up or blow a fuse. if not that then follow the wires back to the computer and check them and the computer

 

On my 1991 EFI 302 I had a problem where it would run OK but after I drove it for a 1/2 mile it would die. I found that the ignition control module was working sometimes then not other times. The module was only a month old.

The only was I found this out was I hooked up a spark tester and ran it for a while.
hope this helps.

 

If he had no injector pulse its in the distributor, the pickup and ignition control module control the firing of the injectors.

 

Well, another day on the Bronco.
I built a test jig so I could better check the pulses to the injectors and found that they are firing.
I checked the play in the timing chain by turning the crank back and forth a little and seeing how far the crank moved in each direction before the rotor moved. It was very little, certainly not enough to cause any problems.
I then remembered that I didn't think the spark was as hot as I thought a TFI coil should be. I replaced the coil with the TFI coil from my CJ7 and the spark didn't look any different.
I replaced the ICM and the spark looks bluer and jumps further to ground. The spark plug that I used in the spark test also had a better spark.
After trying to crank the engine a few times, I pulled the #1 spark plug and it was very wet.
Now I know that I have spark and fuel. It was in time before this problem started so I don't think it is out of time.
Tomorrow morning I am going to turn the key on to pressurize the system with fuel and then remove the fuel pump relay and try to start the engine. There was so much fuel on the spark plug that I think it may for some reason be drowning the plug.
One of the earlier checks that I did on Monday was to pull a spark plug and it was dry but sooty. Now they are wet.
The only good thing about all this is that I want to put a 5.0 HO in my CJ7 and didn't have a clue about how fuel injection works. I think I am still clueless.
I am open to suggestions about anything else to check.
I would appreciate any ideas on why the plugs are so wet.
Jim

 

When I have problems with EFI I check codes-scanner is <$25 and if I have fuel problems I use a fuel gauge for ~$40. Depending on everything you've already done, I'd set timing again. Have you pulled the distributer? Sometimes you can set TDC #1 and have the engine fire on the exhaust stroke instead of the compression stroke. Sometimes the gear on the distributer that fits on a cam gear gets loose. Just another way of being "out of time". Distibuter wouldn't rotate at rotor though. I've bought trucks that were timed without removing SPOUT connector and they run but slow and exhaust manifold gets hot. I would not pull injectors or tear down engine without pulling codes or checking fuel pressure. I do not think your problem is fuel though. I've seen several change coils, ignition module or distributer and end up replacing the PCM. Aftermarket stores can generally get computers at a reasonable price. Just plug it in and check for results. The maxi fuses in the power distribution box near air filter can also blow and prevent computer or ignition from getting voltage. Haynes manual tells how to check injectors but I doubt they all just went out. I've had my share of trouble before too. I put a 302 long block into a LTD once and took forever to get her timed. It didn't run well and I took it to a friend's shop. I ain't no mechanic by trade. He thought computer was bad then figured out I got a 302 H.O. with 351 firing order. He switched some plug wires and it ran fine. I believe the truck ain't firing right yet. The plugs are wet because you have plenty of fuel but fire is not occuring at the right time in the cylinders. My 1/2 penny. Sorry if I overlooked some things. It's late. If you are thorough about everything else and plug wires weren't crossed etc.,. You have fuel and fire and believe timing to be correct, it'd run. If you could not get spark I'd change PCM. Without codes, fuel pressure, etc. we may have to start over. Sometimes by fixing one problem we create others. I don't want to disrespect your ability. I have a lot of experience in certain areas but some days can make the simplest mistake. You do sound very capable and I wish you the best of luck. Maybe I can re read it tomorrow and make more sense. My insomnia is about over.

 

Pull the red vacuum line off the Fuel Pressure Regulator and see if there's gasoline inside it. If there is, replace the FPR.