Coil trouble . . .

[AMC-MJ]

They sold me the long round coil $35, i have the short square coil $75 !

 

Can the 2 be interchanged ? . . . Its snowing i am sure i'll have to report to work soon . . .

 

Mike

[Automan2164]

don't think the two are interchangeable...

 

Rob L.

[AMC-MJ]

:clapping: Wonderful :idea: hopefully i can limp it back to parts store . . .

 

Mike

[jteckmann]

Not interchangable.

 

I ran into this problem at the parts store a lot - their computer keeps wanting to give me standard GM ignition parts (which I assume go with the 2.8 V6 or the carbed version of the 2.5) and not the Renix TBI set up. Getting the right part for the Renix (especially the 2.5) is always more $$ because they're getting rare and not much is interchangible with them.

 

The right coil is the square type and has 2 prongs underneath where it fits into clips on top of the ICU. It's not really a good design, IMO - you'd be amazed at the amount of junk that builds up and is trapped under the ICO and between the coil.

 

I assume you're having the same problem you asked about in the earlier thread (starts/idles fine, warms up, starts sputtering or bogs under throttle)?

 

I had a very similar problem with my 2.5. Started and idled fine, drove under very light throttle, but as soon as I stepped on the gas it would bog down and die. First I thought bad gas or clogged filter. Changed those. Thought it was the pump, but I was getting 15psi at the throttle body. My TPS and CPS both checked out fine. I was at a dead-end, so I started throwing money/parts at it - new plugs, wires, cap & rotor (needed those anyway) and then another coil & ICU out of a junyard, no help.

 

Finally it dawned on me to check the injector itself :doh: Took it off and had the parts store test it, and sure enough it had failed - wasn't producing a spray, just dripping a constant amount of gas into the intake - enough to keep it running at low rpms, but not enough to make it go.

 

The right injector is expensive ($200 from NAPA!!!) and hard to find because it's specific to the Renix 2.5. But it looks exactly like/same dimensions as a standard GM-style TBI (just one injector instead of two). I did some research and found that the the flow rate for the Jeep is right in the middle between the ones used in the GM V6s and the smaller GM V8s. And those are 1/8th the price and readily available at junkyards. I wound up replacing mine with an injector I pulled from a Chevy 5.7. The truck's run fine ever since, and I haven't noticed any changes in performance/economy.

[AMC-MJ]

I was going say, the coil part they handed me looks different then the unit on my truck now . . . It has 2 big round plugs on one end and coil spark plug wire to cap connection point . . .

 

Mike

[AMC-MJ]

second coil, was the right shape but the wrong unit, but after three trip's i got myself the right coil for my truck . . .

 

$85 later we have a coil that fit's and the engine run's so all is good . . . I let it idle for about 40min then took out for a nice drive kinda getting on it and so far it ran smooth and steady as it should, truck seem to run alot smoother now not as much shake & shimmy to its idle . . .

 

Mike