73 CJ5 Hesitation Problems

73 CJ5 Hesitation Problems


73 cj5 304 3spd
Hi, I have a 73 CJ5 with a 304 3spd, 2bbl. I've replaced the carburator, and spark plugs. Timing been set to 5 btdc. Jeep starts and idles great it runs awesome until you floor it and it hesitates at higher rpms. Any suggestions or advice would be greatly appreciated.

  • Fuel Delivery problem, (restricted at higher RPM's)
  • Spark Issues ( only at higher rpm's would suggest within the distributor)
  • Vac leaks
Sounds like it only hesitates when you "floor" it right? So quick fuel delivery could be missing due to dirty fuel filter, pump not pumping good enough, dirt etc in the fuel tank, or again the above small suggestions.

You also mentioned you replaced the carb. Like for like, and jet sizes matched? Did you re-build yourself or rebuilt? etc.

Even if it was pre rebuilt, I might open it up to inspect float levels and other minute settings... There's a good article for the MC2100 / 2150 (can't tell for sure with air cleaner in pics if this is what you have...) http://www.therangerstation.com/tech_library/pdf_documents/motorcraft_2150_carb.pdf

~ JR
Thanks for the tips. The carburator is a MC2100. The one thing I didn't replace is the points, distributor cap, and rotor. I got back from driving it around today and now it wants to stall at idle and coughed out the carb.
What do the points and adjustment gap on them look like?

May be time to either buy new points, clean and regap, or get a magnetic / electronic pick-up like the pertronix upgrade.


~ JR
I bought a new set of points and maybe this weekend I'll get a chance to put them in. I also looked up the Pertronix ignition upgrade. For $70.00 looks like it would be worth it. Thanks again for the useful tips
Get rid of the points and HEI :chug:
You can go HEI or DUI like me, but you can also do this :

Team Rush Upgrade: http://www.jeep-cj.com/forums/f2/teamrush-ignition-upgrade-11416/

I did this: Davis Unified Ignition 40820BL - Davis Unified Ignition AMC Street/Strip D.U.I. Distributors - Overview - SummitRacing.com

But I'll warn you the top on this beast is HUGE and getting the vac advance on it positioned in a way for correct adjustment range is kinda a PITA.

But when I did it I also did this MSD Ignition 5520 - MSD Street Fire CD Ignitions - Overview - SummitRacing.com with it, though it's not necessary, all in all made pretty big difference. That is MSD's "budget Brand" i believe.

I have heard the team rush is a very good mod, and I trust Dave's reporting of it in that thread I linked above.


EDIT: I did try the original distributor with pertronix. It DID make a large improvement over the points. I changed it out only because my distributor has stripped out the holes that hold the pertronix part in (or where originally held the points in the correct location) which never let any of it stay within my adjusted ranges. So i figured GO BIG and did.

~ JR
I didn't see you were in Colorado when I posted last. In this altitude you need to bump your timming up you said you have it at 5btdc I run my stuff at a 8-10 and above.
Thanks JR, the info and links are really helpful and appreciated. I'm going to put the new points and condenser in and see if that at least cures the hesitation problem. If that does help then I'll decide what route to go for updating my ignition.

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a donation.

Help support Jeep-CJ.com by making a donation.
This donation drive ends in
Top Bottom
AdBlock Detected

I get it, I'm a Jeep owner and ad-block detectors kinda stink but ads are needed on this site. This is a CJ site, all the ads are set for autos (some times others get through.) I cannot make them just for Jeeps but I try.

Please allow ads as they help keep this site running by offsetting the costs of software and server fees.
Clicking on No Thanks will temporarily disable this message.
I've Disabled AdBlock    No Thanks