Help: driving through Mexico with some engine hiccups

[alaskajosh]

Suggestions?

This is a RD Mercruiser with the GM HEI distributor and all..

I don't know what clues might mean something but here's everything:

--Shortly before even leaving I had two instances where I was driving along the at hwy speeds and the engine just missed a beat.. just a brief hiccup, then right back to normal.

--Down here the first time I drove on a bad bumpy road I felt the engine was bobbling, missing, but is seemed to go away(I'm not so sure that's related to these other cases).

--Later that same day I reversed to look at some birds and the engine quit and wouldn't restart for several minutes... then ran normally.

--Shortly after that I had two cases, on blacktop and hwy speeds, where the engine cut out for a few seconds. It started back up on it's own with me doing nothing. **Interesting to note that the tach dropped off to nothing during these spells even though the key was on, the trans in gear, and the car moving along a 55mph.**

--Today, in stop and go traffic, it died and wouldn't start back up for several minutes. I would try and it would almost fire.. but then I'd try again and RrRrRrRrR... nothing, no fire. Finally it started and ran normally.

It's not been very hot so I don't really suspect vapor lock. I almost wonder about the ignition module thing in the distributor?? I've heard that those can give fits but didn't know if they'd behave intermittently like that. It seems to be happening more frequently and worse so I'd better figure it out.
Thank you for your time and consideration!
Josh

[83lee]

I'm not an expert on that motor, and I wouldn't want to lead you down the wrong path...but,

...two of my non-Rover vehicles gave me those sorts of problems, and it turned out to be a bad ignition module. Fine when cold, not so fine (and intermittant) when warm. The only way I traced it down was to hook up a high quality digital ohmeter when cold, then heat the module with a heat gun and watch it fail. I forget if this showed a dead short or an open circuit...?

Of course the easy way to trace this is to just buy a new one, install it, and see if it works better...but I don't know your availability down there???


I'm sure others will chime in and suggest you check your fuel filters, loose distributor wires, fuel pump, water in the fuel, etc.........

[stonefox]

No expert here either,But when I had similar issues I was told to check the gap on the points and it took care of the the issue.I didn't have all your symptoms ,but mine came on minor and got to thew point that I could barely drive it. Maybe i'm way off but its a cheap thing to check.
Good luck and tip a few cervasas for us :gulp:

[bkreutz]

I'd be looking at the ignition, since the tach gets it's signal from the dist, dropping off to "0" is a pretty good indicator of something not right.

[Mercedesrover]

Those HEI systems are pretty good but I do remember changing out coils from time to time. As it is intermittent I would start looking at ignition wires that are rubbing on something and grounding out from time to time. There's not a whole lot it takes to power up an HEI distributor...if it gets worse, consider rewiring the power to the distributor.

[frans]

GM HEI:
-Assuming you have done the obvious already like checking all the plug wires, fuses, fuel, timing, etc etc etc-

It prob. is your ignition coil ground or the coil itself. Take off the distributor cap, then unscrew the coil which is beneath it. There is a flat metal strip which is the ground for the coil. Check all the connections, clean and make sure the connections are tight. May want to put some grease on the connections as well.

If you see oxidation or welding of the ground strap in any point that is most likely your problem. If you don't, then it most likely is the coil itself.

If it is the coil you really should not have too much trouble finding another one in Mexico, they are a dime a dozen at any parts shop or wreaking yard.

The problem usually goes away after you let the vehicle cool down all the way (could be a couple few hours)

Mercedes Jim's advice is excellent for getting you to a town if your vehicle dies all together, at least you won't have to walk!

Hope your trip works well for you!

[alaskajosh]

Thanks for the replies!

I trust all the wiring. Just did a complete re-wire and it is sound. New and nice grounds.

I too suspect things in and on the distributor. I changed out the ignition module last night as I had a spare with. I'll look to pick up a coil even though I have replaced the coil relatively recently. The ignition module looked old and not so good. I suspect it's solved with replacing that.

Here's the trip for those who are interested:
http://alaskanrambler.wordpress.com/

Thanks, Josh

[westcoastkevin]

I just read your blog. Sorry about that Mexican mechanic and the headgasket. That sucks in the worst way. Good luck.

[SafeAirOne]

I'm glad you decided to press on. I'm certain you won't regret it, even if you encounter more hardships. Remember, it wouldn't be an adventure if it was an easy drive with an assured outcome.

BTW: Judging by the setting and the activity you describe, it sounds like "the mechanic" they referred you to was "the mechanic" in a Charles Bronson sort of way...