90 F250

Anonymous-0 · Oct 21, 2009

Have a 90 f250 with 5.8 liter seems to loose spark , then will be ok for a week or 2 then act up again . ran good last few times i used it ,went to start it last night ,just cranks ....no spark whats the problem ??

omahagreg · Oct 21, 2009

My guess would be bad coil. Greg

david - or · Oct 21, 2009

Most likely the TFI module mounted to the side of the distributor has gone bad. This can be maddening because the problem is temperature sensitive and intermittant. As you try to diagnose it, the problem goes away.

This is a very common problem with this era Fords, so much so that there have been class action lawsuits over the matter. Do a web search on "Ford TFI Module". Replacement modules, and the special tool to install them, can be found at any auto parts store.

Less likely, but possible, is that the Hall Effect pickup inside the distributor has gotten weak. This problem can interact with the TFI issues, making a really challenging troubleshooting problem since two different problems have to interact. This happened to me on a 90 Ford F150 with a 5.0

Anonymous-0 · Oct 21, 2009

Check the wire harness that plugs into the coil. I have seen tons of the connectors rusted away . They look good ,untill you unlock connector and pull pin out, usually half onf it is gone causing intermittant no spark

Anonymous-0 · Oct 21, 2009

same truck, same motor, same problem. Didn't have the equipment and knowledge to get picky on troubleshooting and local shops wouldn't touch it. Ordered an ignition coil and a distributor assembly. Put the distributor in and fixed the problem.
Haven't been on it in a while, but the folks at the forum below were always real helpful.

Dave

http://www.ford-trucks.com/forums/forum28/

RodinNS · Oct 21, 2009

Most likely the module...
Local garage here that I deal with ALWAYS used to carry a Ford fender module in HIS F350 wrecker in case he needed it... but it often got a rig going instead of a tow.
It was the first thign they'd try.

Rod

UncleTom · Oct 21, 2009

Had a ford Tempo did about the same thing. It would die on the road and start right back up. It was the hall-effect pickup in the distributor.

MF#1 · Oct 21, 2009

My memory is like that, works sometimes then quits! I was thinking Ford had a recall a few years back to replace an ignition item....it "may" have been the TFI module. I would at least run the VIN online and see what comes up. I've replaced one or two over the years, not hard to do.

barn E · Oct 21, 2009

Seems like there is a pickup coil in distributor that the wire flex with spark advance, so they are always moving back and forth. The copper can break inside and the insulation still holds it together but it will work intermittently. TFI is probably easier to change if they will let you return if not the problem. Fifty-fifty one or the other.

90 F250

Anonymous-0

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omahagreg

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david - or

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Anonymous-0

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Anonymous-0

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RodinNS

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UncleTom

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MF#1

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barn E

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