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Unread 06-21-2011, 08:50 PM   #1
Renegade578
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1981 CJ7 
 
Join Date: May 2002
Location: Anaheim, CA
Posts: 89
Howell TBI fuel pump problem

I have an 81 CJ7 with a 258 and Howell TBI. My fuel pump mysteriously stopped working in the crank position. When I first turn the key it engages for 3 seconds like normal and I have fuel flow, but when I turn the key to crank the pump does not engage. I contacted Howell this morning and they had me do a few tests and we determined the ecm was bad. Went and got a new one and the pump still doesn't work. I plan on calling Howell again in the morning. I was wondering if the eprom could have been damaged somehow. That is pretty much the only thing left that I can think of. I went ahead and replaced the ignition module so that can be ruled out. Anybody else experience anything else like this?

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Unread 06-21-2011, 09:02 PM   #2
JonB-CJ7
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1984 CJ7 
 
Join Date: Jul 2008
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I have had issues getting mine to start when I was having low battery issues. The pump would do its initial thing when the key was turned, but would not start until I jumped my jeep.
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1984 CJ-7, Howell fuel injection, D-44 front 4:11 Detroit Electrac,D-44 rear Detroit 4:11, T-19 trans, D-300/4:1 Lo-max gears, 33x12.5 SSRs, Full cage, Warn XDi 9000

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Unread 06-21-2011, 09:12 PM   #3
Renegade578
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Quote:
Originally Posted by JonB-CJ7 View Post
I have had issues getting mine to start when I was having low battery issues. The pump would do its initial thing when the key was turned, but would not start until I jumped my jeep.
I wondered the same thing so I put my charger on it to make sure the battery is full. Have not tried it with the new ecm and battery at 100% yet (although i did meter the battery and it was at 12.5 and 9.5 while cranking). Crossing my fingers that it will magically start up tomorrow morning before I call Howell back.
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Unread 06-21-2011, 09:25 PM   #4
PERK
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1983 CJ7 
 
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had a problem with the kit on a 304. would run fine for a while (usally a couple of miles) the would just die. let it sit and it would do the same thing. howell exchanged the computer twice. no dice...ended up being a bad fuel relay. $10.00 part and has never been a problem .
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Unread 06-21-2011, 09:28 PM   #5
jatepper
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I would start by disconnecting the power wire that goes from the relay to the fuel pump and check the voltage there during crank. This would be the only sure way to tell if the fuel pump is indeed getting power during crank.
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1985 Jeep CJ-7
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Unread 06-21-2011, 09:31 PM   #6
Renegade578
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Quote:
Originally Posted by PERK View Post
had a problem with the kit on a 304. would run fine for a while (usally a couple of miles) the would just die. let it sit and it would do the same thing. howell exchanged the computer twice. no dice...ended up being a bad fuel relay. $10.00 part and has never been a problem .
Did you have to get the relay from Howell or do local parts stores carry it?
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Unread 06-21-2011, 09:58 PM   #7
jatepper
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It is just a standard automotive relay. Either parts store or radio shack.
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1985 Jeep CJ-7
Automatic-258 I6- Detroit lockers front/rear - Superior 1-piece axles, Ramsey Pro 9000 Winch, Quick Disconnects, 33 BFG AT's, 4.10 gears, Howell TBI, DUI HEI Ignition, Ground Pounder Rear Bumper / Tire Carrier Combo, Handen Fab integrated winch plate front bumper w/hoop, ORF weld-in front sport cage.

USMC 1999-2004 Semper Fi!

Hood Hi-Lift Jack Mounts for CJ/YJ/TJ/JK

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Unread 06-22-2011, 09:57 AM   #8
Magical_Merlin
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You can jumper the fuel relay with a wire between the orange and red wire to see if the relay is bad.
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Unread 06-22-2011, 10:06 AM   #9
walkerhoundvm
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1981 CJ8 
 
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I think I had a problem with my relay right off the bat. Exact same symptoms as PERK. I had to take the relay apart to get it through the firewall hole, so I'm guessing I had things a little bit loose. I "jostled" the relay, without a BFH for once, and it's been smooth sailing since. I checked on a replacement relay, and at the parts store they were closer to a $20 part. Eventually I'll get a replacement to keep in the truck...
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Unread 06-22-2011, 01:55 PM   #10
Renegade578
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The relay is good. Talked to howell this morning and we determined that the tach filter on the wiring harness is bad. It is a custom part from howell and costs 50 bucks. Now I am wondering if my computer was fine. I had to give it to the parts store as a core replacement. Hopefully they haven't sent it in yet and will let me test it. About to head over there now.
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Unread 05-12-2012, 07:12 PM   #11
SLO_Ken
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I'm having the exact same problem as the OP. How did you and the Howell tech narrow the problem down to the tach filter? Did replacing the filter solve the problem?
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Unread 05-14-2012, 02:21 PM   #12
SLO_Ken
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Well, I just talked to Troy at Howell. What a nice guy!

Anyway, he had me verify that I was getting power to the fuse block (the three fuse block under the dash) during both "on" and "start", verify that the injectors were getting power to their "A" terminals [they are], had me disconnect the coil connector and tap 12V to the white wire and listen for the fuel pump to come on or the injectors to click [no]. He then had me try the same thing at B5 on the computer [same result, nothing].

At this point, Troy said that the problem was either the computer, or the tach filter in the Howell harness. He had me cut the purple wire going to B5 (to disconnect the tach filter from the harness) and try tapping 12V to B5 again. Success!!! The fuel pump cycled and the injectors clicked!

So now I need to either purchase a new filter from Howell ($50), or try to repair the damaged one I have. It's a pretty simple looking board (photo attached), so I'm going to try to repair it first.

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Unread 05-14-2012, 06:26 PM   #13
dslywalker
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Ken i posted a service manual for Howell the tech one.If you don't have it,it'll save you some bucks
Search Howell tech service manual
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Unread 05-14-2012, 06:59 PM   #14
SLO_Ken
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Yup, I saw that last week. I actually downloaded all the jpegs and combined them into a single pdf document. I went through charts A-3 and A-4 twice before calling Howell.
Unfortunately, the troubleshooting guide is pretty much copied and pasted from the GM TBI service manual,and therefore does not include any reference to the Howell tach filter.
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Unread 05-15-2012, 06:11 AM   #15
cmcstotts
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I had the exact same problem it needed the tach signal from my Summit MSD module. Fired right up once I connected the tach wire to the summit. I am having a flooding issue with my TBI at start up after running a few miles.
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