steelholder

Hello everyone, long time lurker first time poster. Im having issues with my 89 4.9 starting up reliably.It starts up ok (sometimes slow) when its cold. If I run it for an hr or so then stop for gas it takes a long time to start again, gives a very weak crank, sometimes none at all, have to wait 45 min then it can start again. I went to the LPS to test the starter and it passed the test. I then checked the power on my battery and gave me a good 12.7 before starting then a 14.6 while running. Does that mean its the alternator? Is there anything I can check on the alternator with my multi-meter before taking it out, how about my solenoid anything to check on that? Thanks guys.

wde3477

How old is the battery and have you had it load-tested? Are your cable connections from the battery to the solenoid to the starter, and to ground clean and tight? Offhand, sounds like the amps aren't getting to the starter to roll it - such as the battery isn't putting them out, or there's too much resistance impeding the current flow.

Battery voltage looks OK, not seeing a problem with the alternator, although it wouldn't hurt to have it load-checked with the battery.

Good luck, and keep us posted.

MPFit

I’ve got an 89 4.9L also. Same issue. My research has indicated it’s a heat issue at the starter. Once the engine bay gets hot, say from driving around for a while- the headers run right past the starter. It heats up the starter to the point of almost a ‘no start’ issue. It does a ‘whomp.......... whomp......... whomp.....’ but never catches. Wait 20-30min; starts right up.
I’ve installed a heat wrap around the starter which helped a small amount. I’ve read an actual heat shield (simple piece of aluminum between the headers and starter) can help more- even header insulation wrap. I do plan to do it all eventually- but it’s a recreational vehicle for me. And the gas station is only a mile away so I don’t worry about filling when I go straight from my house.
I did however redo all the grounds on my battery, starter, starter solenoid etc. they needed it- and my alternator charge went from 14 to almost 14.6.

steelholder

Thanks guys Ill have more time for this issue this coming weekend, I will be following chrisfixs video on YT regarding faulty alternators and testing with multimeter, Ill report back with and update.

steelholder

OK guys quick, late, update - I had the battery tested and was told that it was in good enough condition to keep my truck working. After having it charged it cranks very well and started up the truck every time for about 2 weeks after it was charged. I almost thought the issue was solved until yesterday, it cranked very healthily but no start. I thought perhaps it was low on gas as the gauge isn't always reliable and it sounded exactly like an empty tank, so I gave it a gallon and still no start. This time I cranked, it started off strong but as my attempts continued the crank began to weaken. Here are my concerns,

If the battery drains out again I'll have to solve that power issue before I can even go back to the futile crank(dang). If there is a power drain, I think it's the alternator as the battery and starter were tested. Could the alternator be the culprit although I had a very good and strong crank earlier? What do you guys think? How should I approach this?

88xlt

Maybe something else went wrong if you had a strong crank from your starter and the truck wouldn't start. I would check for spark through one of the spark plug wires. It sounds like you may need to charge your battery first.

Chris_1

iTrader: (1)

14.6 is what your alternator should be putting out - it doesn't sound like that has anything to do with the problem.
Get a charger on the battery and then you'll have to check for fuel pressure and spark. You should also go over all your starter connections including grounds and clean them up real good.
Your fuel pressure needs to be between 45 to 60 psi - the higher end of that would be better. I'd also suggest doing a bleed down test on the fuel pressure. Turn it on, note the pressure then turn it off. It should hold pressure for at least 10 minutes.

Steve83

Nothing you described suggests an alternator problem, but the battery terminals are always top-of-the-list for any electrical problem. Click this & read all the captions:


(phone app link)

Clean all the terminals on the heavy battery cables.


(phone app link)

If you ever see an actual symptom of a failing alternator, don't replace it. Upgrade to the 3G from a '94-96 truck (or many Ford/L/M cars of that era). It's easy & cheap using JY parts, and the alternator is much safer, more reliable, and more powerful.


(phone app link)

If the alternator is ever off the engine, clean its mounting surfaces:


(phone app link)


(phone app link)

That's all worthwhile maintenance, but it probably won't have much effect on your symptom. When it's cranking slowly, measure voltage across the starter relay's heavy lugs. If it's >1.5V, the relay is probably worn out, like this:


(phone app link)

The later-style relay is a better design:


(phone app link)

If none of that helps, the starter may be failing. But don't skip anything above, or you could end up replacing a good starter, and not fixing anything.

steelholder

Thanks guys, I thought it might be the alternator as my battery seems to be draining. I'll be going back in this weekend and updating soon.

steelholder

Hello everyone, strange issues persist. I replaced the wire that connects the push button start on dash and the solenoid (truck came with a push start not sure of that wire name) due to is degraded nature. I also had a friend let me borrow a good used battery of his to see if that might also help. At first it seemed to work but I drove it about 15 min turned it off and got that weak start again until finally no crank, I was close enough to home to get my car and jump start the truck, so yeah jump starting it did the trick, with the better battery in, where is the smoking gun?

That was yesterday, decided to give it another longer run today, did about 15 miles on the hwy. I was sure it would happen again but when I got back and turned off/and turned it back on, it fired right up. Opposite from what occurred yesterday with the same battery. I just tried turning it on now again about 30 min after the drive and a nice strong start again. My original problem happened when I drove it about 45 min on the hwy, stopped for gas, then got that nasty weak crank, it left me stranded for about 1 hr until it got enough juice to barely start again.
I dont trust the truck even after this recent drive.

** I have tested the starter and original battery (not the one that my friend let me borrow that is in the truck now) at the parts store machines and was told they were good to go. What do you guys think, do these recent symptoms have an obvious source?