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Backfires and runs like crap

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Old 04-21-2013, 10:11 PM   #1
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Backfires and runs like crap

I did a quick search and couldn't find the same symptoms that I'm having. I have an '89 TPI 350 setup in my Jeep. Just about everything is new in it including MAF, ECU, memcal, MAT, CTS, TPS, IAC, rebuilt Bosch 3 injectors, distributor, EST, ESC, O2, plenum gaskets and I'm running a BBK 58mm throttle body (I know it's not needed but I got a great deal on it when I was looking at replacing the stock one since it was gunked up bad with broken bolts).

The issues I'm having is that the engine will have a hard start up, backfire, and just won't idle. I've set the TPS, IAC, fuel pressure never drops below 38 psi at any point, base timing is about 8 degrees, all compression ratios are good, and doesn't sound or act like any vacuum leak (sprayed everything down with no difference). I'm at my wits end with this setup as I just want to get the Jeep running again.

Any help is appreciated. I will be picking up a vacuum gauge later this week to check that out but there is plenty of vacuum in the line that goes to my vacuum canister.
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Old 04-23-2013, 07:41 AM   #2
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Re: Backfires and runs like crap

didnt notice you mention anything ignition related. i'd be checking spark - and also wire condition and especially routing.

And timing! There's that connector with a brown wire you need to disconnect to do the base timing. Is that thing even there?
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Old 04-23-2013, 01:02 PM   #3
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Re: Backfires and runs like crap

Thanks for the reply. The plug is there and I did disconnect it to set the base timing. The wiring harness is a mix between the Jeeps and Camaro's with the majoring being the Camaro's in the engine bay (basically just have the Jeeps basic functions still hooked up: headlights, wipers, start system, HVAC, and brakes).

The distributor, EST, plugs, wires, cap and rotor are all brand new. I will double check the wires tonight to make sure they are in the correct order but they should be as I replaced them one at a time. It's completely possible that it could be ignition related and would sure be a relief as I have spares of just about everything.
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Old 04-24-2013, 06:19 PM   #4
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Re: Backfires and runs like crap

Spark plug wires are all in the correct order (doubled checked just to be sure), plugs, cap and rotor all look good and there is spark getting to the plugs. It can never be that easy.
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Old 04-24-2013, 06:29 PM   #5
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Re: Backfires and runs like crap

now i'd be looking at actual data. do you access to a scan tool or a laptop running live diagnostic data?

I still think its ignition related, but you know how that goes!

Perhaps your timing mark is off? Those balancers - rarely - but do twist a bit. Are you certain youre not 180 off on the distributor?
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Old 04-24-2013, 07:10 PM   #6
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Re: Backfires and runs like crap

What is the fuel PSI?
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Old 04-24-2013, 07:13 PM   #7
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Re: Backfires and runs like crap

I'm definite the distributor isn't 180 off and have played with turning the distributor without the light attached to see if anything happens and all it does is runs worse.

Unfortunately, I don't have a connector for my scan tool to connect to the ALDL connector. As much as I hate to do it but might just end up taking the Jeep to a shop to see if they can figure it out as I have rarely any time to mess with it.
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Old 04-24-2013, 07:13 PM   #8
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Re: Backfires and runs like crap

Quote:
Originally Posted by TTOP350 View Post
What is the fuel PSI?
Fuel pressure never drops below 38 psi and go as high as 50 with just the pump on.
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