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- #61
Here's a pic of where I mounted the fuel pump relay. You may also notice the dirty blower motor. Since it was right there in my face I decided to clean it up. A trip to the parts washer, wire brush, sand paper and then paint.
My TBI adventure...so far
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- #62
Cleaned up the fuel tank straps as best I could. Primed and painted them. Then reinstalled the gas tank and plumbed the fuel lines (I didn't forget the grommets!). The previous owner had installed a bucket seat so that it sat directly on top of the tank bearing the entire weight of the passenger - no other support at all. It's no wonder it was leaking fuel at the seams. I will be looking for a stock bench seat to replace it.
I put 5 gallons of fuel in this morning. So far no leaks!
I put 5 gallons of fuel in this morning. So far no leaks!
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- #63
I decided to mount the ECM in the glove box as others have done. I drilled a 1 3/4" hole in the firewall under the glove box and then another one in the bottom of the glove box. I used a hole saw for this and the sheet metal laughed at my feeble efforts to drill it. By the time I finished the second hole the hole saw (which was new) was ruined. It was smoking and throwing sparks like a cheap sparkler. And while I was drilling into the bottom of the glove box I failed to notice the drill chuck was spinning against the exisiting wiring and tore it all to hell. So now I get to do some more wiring....
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Anyway, my intention is to fabricate a shelf that will cover the ECM and hide the wires. I used velcro to secure ECM and I still need to find a couple of grommets to fit these holes.
You may also see in the third picture a coil of green wire. If you have read any other posts on TBI wiring you will know that this is for the AC control and can be used to increase idle speed for winching.
.Anyway, my intention is to fabricate a shelf that will cover the ECM and hide the wires. I used velcro to secure ECM and I still need to find a couple of grommets to fit these holes.
You may also see in the third picture a coil of green wire. If you have read any other posts on TBI wiring you will know that this is for the AC control and can be used to increase idle speed for winching.
Slow progress? Compared to me you're covering ground like kudzu in summer.
For holes that big something like door edge protector might be easier to find than a grommet.
I used to run through hole saws fast till I started keeping the RPMS down and used lots of lube. They last a lot longer now.
Lookin good!
For holes that big something like door edge protector might be easier to find than a grommet.
I used to run through hole saws fast till I started keeping the RPMS down and used lots of lube. They last a lot longer now.
Lookin good!
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- #65
On Oxygen Sensors
The TBI system requires an oxygen sensor be installed in the exhaust. This means that a bung for the sensor must be welded onto the exhaust pipe within 12 inches of the exhaust port. This is what I had planned to do until a buddy hooked me up with a set of headers.
The issue of the O2 sensor complicates slightly with the headers. The stock GM setup uses a single wire sensor. From my reading I learned that when using headers a 3 wire sensor should be used. This type of sensor heats itself which apparently is needed because the sensor will be located farther from the exhaust port and won't warm up as quickly. This can create an error at the ECM and the system won't run properly.
To address this I went to Pick-n-pull again and snipped the O2 sensor pigtail from a '93 GMC Jimmy (the 3 wire sensor is common on GM vehicles of this vintage) and I ordered a matching oxygen sensor. I chose the AC Delco sensor (pt# 213-632) as I read some negative comments on the Bosch. I found it on Ebay for $66.00. The second pic shows the single wire pigtail next to the three wire. Also in the picture is a the sensor bung, $6 from Summit.
By the way, the three wire sensor is very simple...1 wire goes to the ECM (same as single wire sensor), 1 wire goes to a 12v source and 1 wire is a ground.
The TBI system requires an oxygen sensor be installed in the exhaust. This means that a bung for the sensor must be welded onto the exhaust pipe within 12 inches of the exhaust port. This is what I had planned to do until a buddy hooked me up with a set of headers.
The issue of the O2 sensor complicates slightly with the headers. The stock GM setup uses a single wire sensor. From my reading I learned that when using headers a 3 wire sensor should be used. This type of sensor heats itself which apparently is needed because the sensor will be located farther from the exhaust port and won't warm up as quickly. This can create an error at the ECM and the system won't run properly.
To address this I went to Pick-n-pull again and snipped the O2 sensor pigtail from a '93 GMC Jimmy (the 3 wire sensor is common on GM vehicles of this vintage) and I ordered a matching oxygen sensor. I chose the AC Delco sensor (pt# 213-632) as I read some negative comments on the Bosch. I found it on Ebay for $66.00. The second pic shows the single wire pigtail next to the three wire. Also in the picture is a the sensor bung, $6 from Summit.
By the way, the three wire sensor is very simple...1 wire goes to the ECM (same as single wire sensor), 1 wire goes to a 12v source and 1 wire is a ground.
Nice job! I'm watching closely to this one.....I'll be swapping a TBI v8 into my cruiser soon. Anyway I have done the 4.3 TBI conversion on my jheep CJ7 and, while I know it's a little different application, both the carter and 8153 fuel pumps gave me serious problems at WOT and on grades such as Kinsbury and spooner. Fed up, I called the guys at Howell injection and the guy told me that, while these fuel pumps are deigned for TBI units, they are rated at max psi on a good cool day and when they get heated they won't produce the psi needed under WOT. He told me to put a fuel pressure gauge on there, drive it around and see for myself and he was right. That 8153 after running for a while was only putting out 10 psi and when I romped on it would drop to 2 psi causing stuttering and sputtering. So I got the Howell fuel pump rated at 35psi and it has worked great. I also asked if there was going to be a problem with the fuel pump putting out more pressure than needed and he said no. The TBI unit has a pressure reducer built in and any extra fuel goes out the return line and back in your tank. He also mentioned that the fuel pump stays cooler and lasts longer cause it doesn't have to achieve it's max everytime it's used. Just throwin it out there in case you come into the same problems I did.....I actually threw the carter away when I was mad but am keeping the 8153 around as trail spare....
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- #67
Thanks for that input...I had a tiny sliver of doubt when I ordered it because of the pirate post referenced earlier in this thread. Your comments are really making me nervous about this pump now. I installed the in-line pressure guage so if there is any indication that this pump is not performing, it's outta there. I'll do what you did and keep it as a back-up.
By the way, nice to get some input from a local guy. I've grown up in Reno and spent a lot of time around Tahoe. Hopefully I'll see you out on the trails soon...I'll be the one in the FJ40 with the crazy desert camo paint and a sweet running fuel injected V8
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just wondering if you used a special fitting for the tbi fuel ports to go to the rubber hose and if so where from
you can get the grommet off eBay. just search grommets and you should find it, that's what i did for the 1 3/4 hole i cut.
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- #70
No, nothing special. You can see in this pic the hard fuel line connections to the throttle body when I was tearing it apart. I just cut them off leaving enough of the hard line to slip into the 3/8" I.D. fuel line I used.
So in the picture with the gas tank, which one is the fuel line and which one is the return line?
I would assume the top one is the return line, and use the stock pickup line...
He talked about this on page 2. The one one top is the return. He bought a new fuel sender that had a return line built into it.
I'd add a fuel pressure gauge.
You also have a lot of elbows in the return. If you find your fuel pressure is to high it's probably because of a restriction in the return line.
You also have a lot of elbows in the return. If you find your fuel pressure is to high it's probably because of a restriction in the return line.
I'm in the middle of doing the same thing. But stuck on the wiring harness. can you post where you got your scamatic for the wiring? Or can you post a detailed diagram of yours? So far your post are great. I have had all the stuff for quite sometime but started doing after seeing your post now I'm stuck on the wiring. any help would be great. keep up the good work.
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- #76
Actually, the Auto Zone web site has some great wiring diagrams. Try this link:
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Or you could try this link right here in the tech section. Nice write up with lots of diagrams:
TBI 350 Installation - Land Cruiser Tech from IH8MUD.com
I found this one very useful too. I happend across the link to it on another forum while doing some google searches. The guy that posted it color coded it - just follow the black lines:
http://filebox.vt.edu/users/bmcninne/TBI_ELECTRICAL_MODIFIED.pdf
Finally, here's one more link to a website with some great information on TBI "how to" stuff, not really diagrams. I've emailed the guy (his name is Van and he's super cool) with questions and he was very helpful:
GM TBI Conversion Tips
Hope that helps. I'm planning to post up a list of all the links to various websites I've referenced along with part numbers and prices for everything I've used once I complete the conversion. Good luck!
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- #77
Only two 90's - I thought that was pretty good but I will keep an eye on it.
And I did install a fuel pressure guage
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- #78
Here's a few pics of the oxygen sensor going in. I decided I didn't want to take the time right now to put on new headers and mess with the exhaust. I'm eager to get this thing started 
. The headers can go on once its running and I've worked out all the bugs.
I dropped the passenger side pipe and drilled an 11/16" hole on the top. I then welded on the bung. Keep in mind that I can count the number of times I've welded anything on one hand. I cleaned up the welds as best I could with a grinder and shot some header paint on the raw stuff. Reinstalled the exhaust pipe, threaded in the O2 sensor and connected it.
. The headers can go on once its running and I've worked out all the bugs.I dropped the passenger side pipe and drilled an 11/16" hole on the top. I then welded on the bung. Keep in mind that I can count the number of times I've welded anything on one hand. I cleaned up the welds as best I could with a grinder and shot some header paint on the raw stuff. Reinstalled the exhaust pipe, threaded in the O2 sensor and connected it.
Um you are going to want to put that O2 sensor where it can get a reading from both headers. Putting it on one side means that the computer is only going to get feedback from one side.
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- #80
I don't think it matters. Every other setup I've seen on a V8 has it on one side or the other.
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