TBI no start

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ferrum
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TBI no start

Postby ferrum » Fri Aug 04, 2017 11:36 pm

Since I had all the kinks worked out with my TBI install, my Cherokee has been very reliable until recently. About couple of weeks ago, when I jumped in my jeep to go to work, it didn’t want to start (cold start). Popped the hood and checked on two fuses related to TBI system which were go and tried again. It started up. Once I got to work, I checked on the wiring to the fuel pump which looked good. It didn’t give me any more trouble until today.

I went out to grocery store just before work go grab tub of ice cream and it worked just fine. After bowl of ice cream, I jumped in to go to work and no start (warm start). It cranks over but no go. I checked for fuel pump priming sound and it is there. I’m trying to think what could be causing it not start. Quick look didn’t reveal anything. At this point, I’m leaning towards my ignition being the issue. My ignition is HEI whiteskip version. I guess my Cherokee didn’t want to go to work tonight.

I have been thinking about getting some spare parts since I had issue couple of weeks ago but I really need to get some now. I’m just glad that at least it didn’t fail on me when I was at the grocery store. If anyone has suggestions I would appreciate it.
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will e
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Re: TBI no start

Postby will e » Sat Aug 05, 2017 7:04 am

Squirt a bit of starting fluid down the throttle bores and try starting. If it runs for a second or two you have a fuel issue, if it doesn't start at all you probably have a spark issue.
81 Wagoneer - 'WILL E' Retired

82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau Moab Seats/RCI 6point Harness/Hella Aux lights/tuffy console/killer32 sliders/custom bumpers and roll bar/WARN 8000/steering brace/CO2 Tank/CB/dual batts/custom TC skid plate

ferrum
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Re: TBI no start

Postby ferrum » Sat Aug 05, 2017 11:03 am

Once I got back from work, I tried to start. It started right up. I got intermittent issue. I'm going to give it some time try again in few hours see if problem comes back. I hate troubleshooting intermittent problem.
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will e
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Re: TBI no start

Postby will e » Sat Aug 05, 2017 1:21 pm

I hear ya. No start and won't start is so much easier. Do you have a fuel pressure gauge? I installed one and just love having it. When my electric fuel pump died in Ouray, and the truck along with it, I knew right away I had a fuel issue.
81 Wagoneer - 'WILL E' Retired

82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau Moab Seats/RCI 6point Harness/Hella Aux lights/tuffy console/killer32 sliders/custom bumpers and roll bar/WARN 8000/steering brace/CO2 Tank/CB/dual batts/custom TC skid plate

ferrum
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Re: TBI no start

Postby ferrum » Sat Aug 05, 2017 4:14 pm

I own a fuel pressure kit but I don't have gauge plumbed in. I started again with auto start while standing by it. Heard fuel pump come on and it started right up. Man this is going to bother me but I'm going to drive it till I get this figured out.

I want to get spare fuel pump just in case. My installed fuel pump came with Howell kit. Should I get the same one?
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babywag
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Re: TBI no start

Postby babywag » Sun Aug 06, 2017 10:01 am

Before throwing parts @ it, check the obvious. Poor grounds are a very common problem w/ TBI.
Especially with Howell, I've helped several guys w/ Howell issues, a recurring theme has been poor grounding.

Next time it won't start see if you get spray while cranking. No spray would suggest no cranking signal to ecm.
How is the ignition set-up? Timing control? Or Howell fuel only?
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

ferrum
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Re: TBI no start

Postby ferrum » Sun Aug 06, 2017 12:01 pm

I made sure grounds are good when I installed it. Fuel pump ground comes back to passenger side wheel well near battery as well. Battery cables are new. I checked on wiring connections to rule out the obvious stuff. Mine is Howell fuel only setup with HEI.

I'm not planning on throwing parts at this issue but since I live in Alaska, parts are at least few days away and this is my only daily driver at the moment. I need to get few parts that are hard to get right away on hand.

It started right up today and got me to work just fine and hopefully give me ride back home. Failure to start is on back of my mind and it kinda sucks.
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babywag
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Re: TBI no start

Postby babywag » Mon Aug 07, 2017 7:10 am

For TBI should use an engine ground point, not body.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

ferrum
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Re: TBI no start

Postby ferrum » Tue Aug 08, 2017 7:54 am

TBI ground is currently attached to my old coil mount. Fuel pump ground is attched to the body near battery.

Well, my jeep didn't start again this morning. I looked at the fuel injector while cranking by remote start. Fuel did get squirted during crank but it looked more like dribble than spray. I'm going to hookup fuel gauge when I get home. I hear fuel pump kicking on when I turn ignition to on every time.

How often do you guys change fuel filter? I haven't changed mine since I installed TBI which is approaching 3 years.
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Blake
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Re: TBI no start

Postby Blake » Tue Aug 08, 2017 12:15 pm

how did you crank via remote start? do you have some sort of aftermarket keyless system? I think I would at least consider that as a potential problem. Perhaps it is wired in such a way that it is supplying low voltage to the fuel pump relay?

what kind of TBI is this? My only experience with with GM junkyard setups which have worked very well for me once setup.

those injectors should be spraying full fuel during cranking, not a dribble. If you are not getting enough fuel during crank, then that could be why it's not starting sporadically. I think you should double check wiring to ensure the TBI itself (computer) is on a relay and not going straight from the key switch.

as far as changing the filter, well, that could be your problem. I was having some strange TBI behavior over the past few months that was getting progressively worse and worse. more of a lean condition and not a 'no start' condition and the problem was my 3 year old fuel filter. I honestly had forgotten to change it. I use those cheapy clear plastic ones with 3/8" nipples before the pump. then I have nothing between the pump and the TBI other than 3/8" hose.

ferrum
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Re: TBI no start

Postby ferrum » Thu Aug 10, 2017 5:45 pm

I have after market remote start system installed about 2 years ago by myself. It is not the cause of issue but nice when I need to start the jeep for troubleshooting.

I purchased kit from Howell fuel only. Had some trouble with cold drivability but it had been taken care of by New chip/program from HamiltonTBI.

Once I get it started, I don't seemed to have problems driving my jeep. I would think if I have issues with fuel pump/filter, something would show up during drive.

I thought my trouble may be in the ignition. I opened up the cap and found stuff on the terminals in the cap and rotor didn't look well. I purchased this large cap HEI 6 years ago. I cleaned up the terminals and rotor best I could and drove couple days.

Replacement cap and rotor showed up today. Once I replace cap and rotor it starts and idles better.

For those of you who have large cap HEI, how often do replace cap and rotor? On the rotor, I can see that it is worn but cap terminals were dirty and cleaned up. I would appreciate your opinions.
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FSJ Guy
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Re: TBI no start

Postby FSJ Guy » Sat Aug 12, 2017 2:32 am

It sounds like replacing the cap and rotor did the trick.

I am personally not a fan of aftermarket "HEI" distributors. I think the factory distributor (with or without the "large" cap) works just fine. YMMV.
Ethan Brady

http://www.bigscaryjeep.com

1987 Grand Wagoneer. Slightly longer than stock.

ferrum
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Re: TBI no start

Postby ferrum » Sat Aug 12, 2017 4:34 pm

If I knew what I know now, I probably went different route. It is what it is. I'm going to work with it best I can for now.
I kept all my old components just in case. I appreciate troubleshooting suggestions.
'76 Cherokee Chief


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