frank

Hello people,

I've just bought myself a Ford F150 4,9 1994 and I have a strange problem.
If the car is running sometimes he runs on 3, 4 of 5 cilinders and when I stop the car for short shopping and start the car again, most of time he runs very smootly on 6 cilinders. I think it's a problem with the hydraulic lifters or it's an electrical problem.
Maybe someone with the same experiance can help me further.

wde3477

Welcome to the site! I see that you are from Holland - I've been to Gennep a few times for a past job - very pretty countryside there.

The 4.9L engine has been proven very reliable - haven't heard of any lifter issues.

Are you getting any 'check engine' warning lights? If so, the computer has flagged something which may help troubleshoot your problem. Suggest to get the codes pulled with a code scanner.

If not, suggest to go through the ignition system first. The way you describe the problem, it seems that the failures occur when the engine is hot, then the problem disappears after things have had a chance to cool a bit. Suggests that the problem could be electrical.

Perhaps first check the ignition coil and plug wires - there are tests that can be performed with a voltmeter to prevent blindly changing parts on a trial-and-error basis. I don't have the specs for a '94, but for the '87-'91 model years, the plug wire resistance should not exceed 5000 ohms per foot (about 300 millimeters), resistance on the primary side of the coil should be between 0.3 - 1.0 ohms, and the resistance on the secondary side should be 8000-11500 ohms. I suspect the values for the '94 model year should be about the same.

Good luck, and let us know what you find.

NGM

I would inspect the cap and Rotor to start with.

MayDFXForceBWithU

One of my buddies had a bad spark plug wire and the mechanic told him it wasn't even firing so he was running on 7 cylinders. maybe check the wiring too?

BIG D

I had the same problem with my truck,ran fine when cold or just started,but when the engine was at operating temp. it would miss and be very sluggish,i ended up changing the ignition control module and it ran perfect afterwards,have had the same problems with other trucks at work also,once the ign. control module got hot it would start to fail,suggest replacing the module after you check plug wires, etc.

iluvmyford

most of the time a weak link in the ignition system can cause other parts to fail premarturely.

rednas15

i need some help, i sawed off my muffler its a 2000 f150 5.4 and now it sounds bad *** sounds really good, but now that it does not have a muffler should i go with the smallest piping?

Drakebuster

Has nothing to do with this thread.

frank

Hello,

Thanks for the fast replay,
Nice to hear you like our country, but I don't know anything from Gennep, it's a small town about 145 km from my city near the German border.

I do get several times the "check engine" warning but it make no differance if the engine is cold or warm. Sometime when I start the engine in the morning he runs immediatly on 5 cilinders and sometime he run very good on all of the cilinders.
Sometime I start with a cold engine he drives ok but a few minites later he runs terrible.
If I stop by a shop of something and start the engine then he runs smootly. I do think too that it's an electrical fault and have asking a friend of my if he can pull the fault codes with a scannner and he will on monday.

Alle the ingnition wires I have already changed.
If I have more information I let you know, thanks again.

frank

Thanks for the replay, I have changed already