1970 Jeep Rebuild

Boy no kidding. I thought it was just me that happens to.

 

I didn’t get any pics yet but I dropped my intake off at machine shop on my break this morning and it was done when I took my lunch at noon. I should be able to get everything back together after work tomorrow if I get off on time.

 

NOPE!

 

I got the intake welded and installed on Sunday. My buddy at work has a Snap-On scanner he lent me so I can see where my numbers are at on my TBI system. ( have video but can’t post)
My MAP sensor is throwing a high voltage signal on cold starts. Once engine is warm and I clear codes it won’t throw the code until I do another cold start. My block learn numbers are a little high indicating running lean. I increased the fuel pressure and they came down to low and fuel pressure was at 25psi, way to high. I lowered the fuel pressure and it dropped to 10psi, I changed the setting several times and settled at 12.5psi. Block learn numbers are a little closer but still not where I want them.
The TBI is still searching for an idol. Was talking to Norcal69 and he’s thinking that my lack of vacuum in the motor is throwing the MAP sensor into a frenzy and causing the surging.
Ran out of time tonight so I’ll pick up again tomorrow.

 

Thanks for the update, Rob. I was wondering how it has been going.

 

Update?

 

I haven't got very much time to work on it, just hour here and there.
I did borrow a scanner from friend at work and have been able to run some numbers. I fought a low vacuum issue that was throwing a high voltage code for the MAP sensor. I was able to bring up vacuum up by advancing my timing up to 14* btdc. I also found a small vacuum leak at the adaptor plate for the throttle body, was able to run a thin layer of grease to fix this, now I’m getting 15 inches of vacuum at idle and 30-34 inches above idle.
I’m fighting an issue with the idle hunting from 600-1125 rpms. I have done the IAC calibration 5-6 times and it will settle in at 500-550 for about a minute then start surging again. I did get it to settle in to 500-600 and stay there. I took it for a drive around the block and about 2 minutes into my drive it started popping through the throttle body so I limped it home. When I pulled into the garage the idle was back to hunting between 600-1125 again. I havnt messed with it since Tuesday. I do have tomorrow off so I’m gonna mess with it some more.

 

I spent several hours on Friday adjusting several things to see if I could get this thing to run, it’s about 70% there but still needs tweaking.
NorCal69 and I have had more then a couple conversations about the tune that was sent with the Howell system not being right for a modified motor, so he shipped me his ECM with custom Prom chip to see if it was better suited to my motor, received it yesterday, thank you Kyle, extra cold beers will be paid on Rubicon trip.
I started off by calling Howell to ask a few questions and talked to Troy who after half listening to my question gave me the cure all fix to all my issues…NOT! Told to get rid of 8” vacuum line I was using on my MAP sensor and only use 1-1/2” line, this didn’t fix anything!

i installed new ECM with new chip. I was running 12.5 lbs of fuel pressure with old chip but this chip was not happy with that and was running Block Learn numbers at 140, which is way lean. I played with the regulator and have it set at 14 lbs and it was idling with Block Learn numbers at 128, where they should be.
It took several times for the IAC re-calibration to work and keep the idle at the set 600 rpm, this only happened after I noticed that the TPS sensor voltage was at 1.2 volts and needs to around .52 volts +/- .06 and got it adjusted correctly by slotting the holes in the TPS sensor so it could be moved. Also was running where I was getting no popping through Throttle body while stabbing the throttle in garage. Took it around block and it did run better but would pop through both throttle Body and exhaust while in 3 rd gear trying to accelerate. In 2nd it would wind up to 4k and not pop at all. Looking at my Block Learn numbers they were reading in the 140’s while driving down the road, lean.

I ran out of time to continue because wife has me doing honeydews but I need to add 1-2 lbs of fuel pressure to see if this helps with my Block Learn numbers and the popping through the throttle body and exhaust.

if anyone is looking at doing a fuel injection set up on their motor, it is not a plug and play, you need to read and understand what each sensor is and does and what effect it has on the system over all. You will also need access to a scanner to make any adjustments.

 

Definitely for the gm based systems. Way too many variables with each engine.

 

Well I had about an hour in the garage after I hung a ceiling fan in master bedroom and painted master bath.
I was re-reading NorCal69’s thread on his fuel injection install, and read in post # 164 that he had hooked distributor advance to the ported vacuum port instead of manifold vacuum port and was having some issues, until he put the vacuum advance on the manifold vacuum port.
I went out and looked where my vacuum advance was hooked up and I had mine on ported vacuum port. Changed it to manifold port and bumped up the fuel pressure by 1 lb and tried driving it around block again…. Success! Was able to row through the gears and no popping through the throttle body or exhaust!……one step forward.
Still running a little lean, Block learn numbers 140 and integrator number 135. I’ll bump up fuel pressure by 1lb at a time and test drive until I get closer to 128 on both numbers.
Right now I’m happy, I can actually drive it down the road. Now I can start fine tuning.

 

Whoohoo!

 

Glad you got it. What an ordeal. Seems like a lot of unnecessary drama with Howell.

 

I’ve had a couple sleepless nights. I was hoping for an easy fix and I’m glad that I was able to figure it out. Now I can get to fine tuning this thing.

 

I spent a couple hours fiddling with my fuel injection today. I can make the JEEP backfire through the throttle body consistently at around 2100-2300 RPMs in 3rd gear going down the road. It feels a little sluggish also.
I’ve re-checked my ignition system, timing is at 12* BTC with vacuum blocked off and the advance will add another 23* for an all in of 35*, new plugs, new plug wires.
Tomorrow after work I’m going to check compression on all the cylinders, this should let me know if I have something wrong with the valve train that might be causing the backfiring.

 

I finally got some time this week to play JEEP. I started by warming up the motor then pulled all 6 plugs, they didn’t look bad except #6 it was black and sooty. I had put new plugs and wires on when I put the fuel injection on. I checked all the cylinders and all were pretty close.

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#1, 3, 5 looked pretty good. #3 was a little more sooty but not to bad.
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#2, 4 looked good…#6 was pretty dark.



I had bought a new set of plug wires from DUI when I had got the distributor refurbishedd. But decided to try something and put back the old plug wire on #6. Took JEEP around block and it felt a little more zippy then it had and no backfiring through intake while accelerating. It did backfire through exhaust while down shifting. I’m running fuel pressure at 15psi, block learn numbers are 130-133 at 60 mph, so it’s a little lean, 128 is target number. I’ll kick up the fuel pressure to 16psi tomorrow and take it for a drive and see what I get. I also might add a little timing to the motor.

 

I took JEEP to gas station to fill up so I could take a drive to let the computer learn. I didn’t even make it around corner before this thing was backfiring through both intake and exhaust, so back in garage it went. I put timing light on it and it’s right where it was set at 12* advances to 35* with vacuum line connected and rpms around 2500-3000. Checked all vacuum outlets and all were capped. Put vacuum gauge on it and it was pulling 25-30 inches of vacuum. It was idling fine around 575-625 rpms. The fuel pressure was at 15 lbs.

I changed quite a few things when I installed the fuel injection like the distributor, plugs, plug wires, and new cam gear and distributor gear. I also changed all my fuel lines and filters.
So I wanted to go back with a known item that worked, so I took throttle body off and back on with the Holley!

'
Took about 2 hours to put carburetor back on and wire up a relay for electric fuel pump and reroute the fuel lines. I didn’t even adjust anything I just took it on a road test and it didn’t pop once.
That being said, it is the throttle body or the tune that is causing the backfiring.
I’ll get the throttle body back on and go from there.
at least I know if push comes to shove I can switch back to the Holley to run Rubicon this year if I can’t get fuel injection dialed in by May 1st.

 

What a PIA, (says the guy about to put FI in his jeep). Is Howell just no help whatsoever?

 

They have been no help at all. Kyle has been helping me as much as he can, he even sent me his ECM with his custom burnt chip. One day it seems to run and the next day not.
I have learned so much about fuel injection, it’s not that hard.
I’m watching your build very closely, because I’m gonna be building my 52 Willys pickup with a GM 6.2. Good luck with

 

How difficult is it to swap out the injector or test it for proper operation?

 

With the fuel pump running a 9v battery from the nearby smoke detector will fire the injectors.
Otherwise you use a timing light and look for a even spray out of the injectors. If the rig isn't running you can use a nearby motor to trigger the light and the smoke detector battery on the injector.

My kit (not from howell) had a stuck injector out of the box. My tbi kit like my carb rebuilder had me call before start-up and run through the checklist then I called with the injector issue and they talked me through the troubleshooting.

I need to look through the pictures again for the o2 sensor location. Another question I have is if the iac and tps were adjusted.