1989 318 TBI ignition questions

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ragtopfury

ragtopfury

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So here's the questions of the day, because some of you are smarter than me.
1989 318, factory 2 barrel throttle body. I'm switching to a 4 barrel set up.
Do I have to convert the ignition to a stand alone system, such as a mopar electronic set up? Pertronic, MSD?
If I leave the ECM plugged in, other than a check engine light on the dash, will the original ignition function properly? There is no crank sensor.
 
I converted a 88 d250 to 4 barrel carb,,,,but I removed the ECM,,,,,and wired in a Mopar style electric ignition,,,,
 
I've never worked on those. Does the ECU control timing? Easy to tell does it have a vacuum can? Does the rotor "spring" against a mechanical advance? I bet it's electronic. If so you'll need the TPS. You might have to "dummy" the injectors into the system to fool the ECU, IE pull the injectors out of the TB and connect them electrically, roll em up in a bag or whatever. "You might" be able to sub a couple of appropriate resistors to fool the ECU
 
Better to go with the mopar stand alone ignition.

Then you manually set your own timing, instead of having the onboard computer trying to adjust it for you through sensors: oxygen sensor, throttle positioning sensor all used wth the factory ECU.

Screenshot_20210402-080211_Gallery.jpg


90 318 TBI conversion to 4 bbl with points distributor on engine run stand.
20200711_214031.jpg
 
This will be in my Shelby Dakota that I'm building the 360 for. I have the parts to go mopar stand alone. Was us wondering if I really needed to.
As for losing the ECU, I'll have to also look deeper into if it controls any of the gauge readings in the dash.
Thanks for the insight folks!
 
Lockup converter on the transmission is a consideration too. They made a lockup type and a non lockup type in those years.

The original automatic to this '90 318 TBI was a non-lockup converter designated by the 2 pin terminal by the shift linkage.

3 pin terminals were for the lockup converters. Some folks have manually switched them for hot rod / non factory setups.

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Also as you know 360 is external balanced and the original 318 was internal balanced, so going to need that special notched out flex plate for the 360 setup with automatic.
 
I am looking at the same issue with my son's truck right now. 2 things I know are the Air Conditioning has a relay that would cut the AC compressor at WOT and the cruise control was run through the computer as well. Good luck with the change over!

Cley.
 
There are a few threads on FTO about this, good info I have a 88 I am thinking about doing also.
 
ragtopfury said:
will the original ignition function properly?
Click to expand...
AFAIK that 89 is a LeanBurn with NO V-can and a fixed rotor. The Vcan you see on the air-cleaner is a load sensor. It tells the ECU how hard the engine is working. Together with the Rpm sensor, The ECU determines how much timing it's gonna let the engine have. and it's never enough.
So while the OEM LB computer will run your engine ,
the only way you can tune that thing is if you can change the timing curve, so your D needs to have flyweights in it and a Vcan. Otherwise what's the point of installing the 4bbl? With retarded timing, it will still be the dog it always was.
The LB system is pretty relaxed about timing and is one of the reasons those engines are also pretty laid back.
But if your 89does not have a LB, then you still need an adjustable D and stand alone ignition system. As for a coil, I highly recommend the Accell big square top, with it's recommended ballast; it will fire anything at any gap all the time and mine was new in 1999, and it won't burn off your plug electrodes. My plugs were new in 2004 IIRC. Cheapest coil, in the long-run, I ever bought.
 
Yeah, you definitely can't use the TBI distributor. Best to use older style electronic or a points distributor.

Cley
 
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