PhilisDiller

The picture I took is with it at true TDC

The trailing edge of the rotor is just a hair before the beginning of the metal for spark 1.

Just thinking about it logically, I can’t imagine how it could be off that much and not be the harmonic balancer. The thing is that I’m not driving this truck right now until I can get the closed loop issue figured out. I’d rather not throw money at it right now unless it’ll improve how it runs. The fiancé is asking how much more money I’ll spend on this broken truck 😢 once it’s running good, she won’t worry so much about how much $ I spend on it 😈

I just confirmed true TDC using a screwdriver and got an average mark between the marks I made with the screwdriver maxing out both CW and CCW. The notch in my harmonic balancer is at 20 degrees. there’s nothing else that would cause it to be off that much right? It’s gotta be the harmonic balancer

Ah dang, is there a reliable way I could tell that it had slipped before I buy a new one? Looking at the mopar 33002920AC and they are about $130. I need to reference the fuel injection manual but I thought it used the flywheel teeth to determine timing. so aside from a risk of the harmonic balancer failing, am I wrong in thinking that a slipped harmonic balancer shouldn’t be causing any of the issues I may be having?

I’m not sure what you mean here. I didn’t see anything in the write up about it being .020” past. I checked the rotor at the 12 degree timing true TDC and the trailing tip of the rotor lines up exactly with the beginning of the spark 1 metal piece. with the degree timing mark set to 0, the trailing tip of the rotor is lined up at the middle of the spark 1 metal piece. I don’t understand why my 0 crankshaft balancer mark wouldn’t line up with true TDC... is it possible the PO messed with the timing or is this normal? Everything I’ve read leads me to believe it should be 0 when at TDC

Okay I think I answered my own question. It was at TDC exhaust stroke. I did another rotation to compression stroke (hence the pressure test) and as expected I’m still 10-12 degrees off. It’s more like 12 degrees. The trailing edge of the rotor is lined up perfectly with 1 when it’s at the 12 degree position. My guess is the PO already indexed it.

I’ll be picking up a vacuum gauge next week after a road trip that starts tomorrow

Hey all, I cut the window in my distributor to index it and it looks like it’s waaaaaay off. Almost 180 degrees off. See picture I wanted to verify exactly what top dead center should look like. I can’t fit my finger over the spark plug hole to feel the pressure from the cylinder, but through the spark plug hole I can see the top of the cylinder rising up as the timing mark on balancer approaches the 0 mark. Here’s my issue, as I’m watching cylinder#1 rise, it actually reaches true TDC when the balancer mark is between the 10-12degree mark. As I continue to rotate the crankshaft bolt clockwise towards the 0 degree mark, the cylinder actually travels downward a bit. Is this normal? I thought true TDC should be when the crank balancer mark is at 0? I’m not sure why the photo is upside down. It’s right side up on my phone when I upload it.

I'm sure it's feasible. Unless you have concerns about the quality of your wiring all the way through, I would definitely solder eliminate the C101. Took me about an hour and a half. Also, you can eliminate some of the shoddy ground crimps that they do from the factory. I would imagine that a harness swap would probably take 3-4 hours at least. What's the reason you want to swap? What's your ground resistance at the MAP and your ground resistance at the O2 sensor? I think I've seen different dash clocks throughout the years so you'll probably have some issues there.

I love my buckets, although I haven't sat on a bench before. Regarding the color, I love the blue interior. Tough decision there man. I bet the gray seats would look good with the blue interior.

Good to know! I’ll have to take her for a long cruise on the Highway then. I can get some mpg numbers too for reference. Just got to get temporary registration... been test driving her around with a farm plate. Haven’t tried registering/emissions yet, knowing I’ll fail.

Hahaha it was dinner time with me lady, so that took precedence. well, I took her out for a spin and it looks like it’s able to maintain closed loop decently while cruising at a steady speed and throttle. But if I am going up or down in speed, a lot of the time it fails to keep closed loop. Also, it’s now failing to keep closed loop at idle again... I can see right as ST is approaching 0, the o2 sensor start to swing but it’s too late and it fails into open loop. okay, since my fuel pressure is good, the issue shouldn’t have anything to do with my fuel pump right? I am going to try and reindex her tomorrow, but other than that I’m stumped... I know I post way too many videos, but this little REM is helpful and I had me lady take a 2 part video driving with and then I took another one idling after the drive (Don’t mind my comments at 30 seconds on the idle video. I forgot open loop was 6.9mS pulse width before the drive too.)

So I received the injectors and installed them today... she can maintain closed loop at idle now! Still not perfect though because the ST has to drop down to 10-30 to maintain idle. The swings in o2 voltage are a bit long... I haven’t taken her for a drive yet but I’m happy i made some progress. Can Anyone make sense of why I’d be at the ST level? ive attached a video of her idling where I had warmed her up already and then shut her off. I reset the LT to 128 by holding the battery cables together. The video I took is right after I started her while warm and was still in open loop.

I second the REM as a must have item for any renix owner. I’ve been diagnosing some issues with my truck idling and I can’t imagine how much more stressful it would have been without this device. If you’re on the fence, just buy it. It’ll save time, money and headaches. Thanks a million Nick, you’re awesome.

I just did my connector elimination and had 3 or 4 wires that didn't go to anything. I just terminated them and made sure the ends were insulated. I don't know about the oil sender though

@Ωhm I like the explanation! I hope the different injectors solve my problem too. does anyone know what the specs of the OEM injectors on an 87 4.0 are? edit - the renix FI manual says it should have 16 ohm resistance. Well looks like The ones in there currently are definitely not 16. I just hope I haven’t fried anything on my ECU yet with the different resistance. It’s a remanufactured ECU already. I wonder what f’ed up the old one...

I ordered some remanufactured Bosch 746 injectors that will be here next week. The ones that are in there now are no-name 700 injectors. my hope is that the no name 700s are just junk, because it seems like the difference in these two units are negligible. Is there a reason why 746s are the go to injector to install, but not 700 or 710 from the fords? I've seen a few people installed the 710s, but I keep hearing that 746s are the way to go even though they seem similar enough... Also, pardon my ignorance, but how does the resistance difference between these two injectors impact the performance?

I tapped my intake and swapped in the correct sensor. I made a nifty contraption that utilized my brake booster vacuum line, a random brass pipe fitting, a cut up beer can and some tape attached to the shop vac nozzle to ensure no shavings could get past.The temperature is now correct - ambient air temp when cool and stupid hot heat soaked air when hot - just as the engineers designed it. Also, I looked at my ECU to make sure i had the correct one and found that this is a remanufactured ECU. IDK Who remanufactured it but it looks pretty new. See attached image. i went through and retightened my intake/exhaust bolts/nuts. They were all snug, but I got a 1/8 turn out of some of them. overall, the car doesn’t run any different. I took a long video of me driving around today and it’s really interesting watching the O2 sensor. It’s acting quite strange. The O2 reading after warming up was around 0.4v. while driving around at lower RPMs it stays pretty constant, but when doing heavy acceleration, the O2 starts fluctuating between 1 and 4. When I let off the throttle and fuel is cut, it reads a 4.8v. So it is able to sense the fuel cut immediately, but seemed to be finicky about when it wants to have the O2 swing. Watching my video again, it seems to only want to swing when it’s in closed loop driving and ST is bouncing around the low 10-50 range, but it also sometimes doesn’t bounce at ALL when in closed loop. you can see in the video - at 6:10 that as I’m accelerating in closed loop, the o2 doesn’t start swinging until the ST is quite low and then when I let off the throttle to shift the ST goes back to 128 and the O2 stops swinging. As the ST drops below 50 the O2 starts swinging again. During this time I have relatively constant throttle and driving conditions and you can see my duty cycle drop from 17% to almost 13% before the O2 levels are lean enough to be registered. It seems like the O2 is just stuck reading stupid rich until the fuel is trimmed a bit to be within more normal A/F ratios. Makes me think it’s getting way too much fuel. I even double checked my Injectors were opening/closing properly by placing a screwdriver tip against the body of the injector and the handle up against my ear. Can hear the little ticks on all them. Fuel pressure again is 31/39. Any chance these injectors could be knockoff ebay injectors? I’ve attached a photo.

Thanks for the great writeup! This is perfect as I've been getting ready to look into repairing my rust once the motor is happy

If you end up just doing the o-rings withou new injectors, make sure you save a couple of your old o-rings just in-case one of the new ones tear on the way in. They only give you 12 o-rings and if ones messed up, you're SOL. I found them to be very difficult to fit back into the fuel rail, but with vaseline and a LITTLE bit of wiggling, they will go in. If you wiggle at too much of an angle, the o-ring will bind and get ruined... don't ask me how I know

I just used Vaseline when re-installing the injectors with new orings. I can tell you they WILL bind and pinch/tear if you don’t use something like Vaseline. I’d also recommend just getting a set of injectors that come with the rings. You’ll pay $10-$15 for just the orings alone.

Fingers crossed on the intake temp sensor. I ordered the GM one recommended by Ohm and it’ll be here Friday. Picking up a tap set. Do you recommend taking the throttle body off to keep shavings out of the manifold? Or does the manifold need to be taken off for the install? anyone have a renix butterfly valve stopper bolt they would sell? It seems that renix jeeps don’t make their way down to Durham NC junkyards. I'm going to measure my valve gap with a spark plug gapper to try and get it to 0.004”. I’m thinking of just adjusting the bolt by grabbing the extruding part of the bolt with a wrench and rotating. I’d like to get a new one, but thinking temporarily.

I am looking for an orange with black wire. I see one in the harness where I elminated the c101. I also see a orange with black wire going into the EGR solenoid. I can’t find another one. on the passenger side of the engine bay I see another one but none of them are single wire connectors. This is the photo I’m using for reference. My wires should be the color right?

what’ll you let one go for? I just double checked and it is a 1/4” NPT. It was actually a pink wire. Anyone know what color the fuel pump relay wire is?