Author Topic: REBUILT HT4100 AND LIITLE POWER  (Read 2358 times)

DAVE DOLAN

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REBUILT HT4100 AND LIITLE POWER
« on: January 06, 2005, 03:04:30 PM »
THE HT4100 WAS COMPLETELY REBUILT- INCLUDING NEW OIL PUMP
YET THIS CAR WILL NOT GET UP A STEEP STREET AT OVER 30MPH
NOR WILL THE CAR MAINTAIN 65MPH ON HILLY HIGHWAYS-  IT STRUGGLES
JUST TO REACH 70MPH ON A FLAT ROAD- THE CATALYTIC CONVERTER
IS UNCLOGGED- ANY IDEAS ON WHAT WRONG AND WHAT TO HAVE THE
REBULIDER DO WHEN THEY TELL ME THAT THE MOTOR JUST WASNT EVER VERY POWERFUL- I KNOW THIS- BUT I DONT THINK CADILLAC WOULD OF
SOLD ONE WITH THESE CAPABLITIES IN 1984

Mike #19861

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Re: REBUILT HT4100 AND LIITLE POWER
« Reply #1 on: January 06, 2005, 05:33:13 PM »

 While the HT4100 is no power house, it is able to easily keep up with traffic and can cruise easily at 70 mph+ speeds. There is something wrong here.

 I would bet it is an ignition timing problem, if you have eliminated the possibility of a restricted exhaust.  Make sure the distributor has been correctly installed. I know in a RWD car, this can be a bear to get at. Then be sure the timing has been correctly set as per the sevice manual. This should clear up the problem. Also, it has been found that by advancing the base timing a few degrees more than what is recommended can really wake up these engines with no ill effects.

 If this does not clear it up, make make sure the cam timing is correct. This can be a big job to ascertain, but it may be necessary to clear up this possibility. It is suspect with a freshly rebuilt engine.

 You can also check for DTCs to see if any exist. If so, diagnose for and repair. Perhaps this could be part of the problem. Over or under fuelling caused by a defective sensor can cause a lack of power and adversly affect fuel economy. Verify a good ECM as well.

 I would recommend obtaining the correct factory service manual as well. Such symptoms are outlined in section 6E.

  Mike

Randall Ayers McGrew CLC # 17963

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Re: REBUILT HT4100 AND LIITLE POWER
« Reply #2 on: January 06, 2005, 05:37:27 PM »
I second Mikes advice here (not that I know anything of what he knows).  My 77 Eldorado was a total DOG until we replaced the distributor and then it ran worse, if that was possible.  We later learned from the Cadillac dealer in Denver (a long running name with supporting older Caddies) that you have to know a little trick to get the damn thing to settle into the correct gear space, otherwise it is off and the engine does NOT like it.

Good luck!

Bob Chesnutt

  • Guest
Re: REBUILT HT4100 AND LIITLE POWER
« Reply #3 on: January 07, 2005, 01:03:14 AM »
I canat say this is your problem, but the 4100 is very critical on the routing of the plug wires.  They have a problem bleeding through to another wire and that misses things up.

Correct routing of wires is shown in the 1985 shop manual.  I expect it is also in 84 shop manual and others.

JIM CLC # 15000

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Re: REBUILT HT4100 AND LIITLE POWER
« Reply #4 on: January 07, 2005, 03:12:20 AM »
01-07-04
Dave,has the fuel filter been replaced? If not, I would suggest replacn it, on age/mileage alone.
I had an 86 Cad and the only time it loss power was when the fuel filter needed to be changed. I had to replace it two times in twelve years.
HTH
Good Luck, Jim

Robt.Vonheck via SanDiego Calif.

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-Rebuilt HT4100 with little Power...
« Reply #5 on: January 07, 2005, 09:39:37 AM »
dear DaveDolan:   -YOU DONT HAVE TO SHOUT!  Please learn what your PCs keyboard/Shift-key is for, as it makes reading much easier you see...    :-)   ~Bob vH