235 inline 6 running of fuel injection

[drummin89]

YouTube - 235 inline 6 fuel injected

all that is really left is to just load the tuning software onto my laptop and set the egr so that it will never come on. Currently it has a slight high idle, at about 900rpm. Im going to check for vacuum leaks as that can cause it to want to idle high.

If anyone is interested and as time allows I will post a list of everthing I used. The basics are a 4.3L V6 TBI unit, sensors (some not used) and harness (unused circuits removed) out of a 88-92 Chevy 1500 w/ of coarse a 4.3L V6.

See the link in my signature "Various pictures of my 52 Chevy 3600" to see my photobucket album. TBI conversion pictures are under album "TBI conversion".




Dammit I made a spelling mistake in the title, oh well.

[1-ton of fun]

nice project, looks great, good use of junkyard stuff. that efi should help with mileage and driveability.

[hotrodsbyray]

would love to see more detailed info, parts list, how-to's!

[dwcsr]

nice work,,,very inpressive! Post what you can on the parts list.

[drummin89]

thanks for the compliments


I will be working on a tech tip that will be posted in the tech tips section at stovebolt.com

[drummin89]

OK im putting together a rough draft how-to on installing Throttle body injection on these older inline 6's, but this can also be used for other vehicles as well if you pick the correct donor vehicle.

Anyways it will become a tech tip over on the stovebolt.com board and here as well. Before I get that finished I plan to post a basic list of everything needed.

[rss396]

Subscribed. What distrubutor did you use? Crank sensor, cam sensor, map sensor, coolant temp, oxygen sensor, and spark advance. Cool !!!! Points and carbs suck compared to simple TBI fuel injection. My opinion.

[drummin89]

For the distributor I used a modified to fit, GM 250 Inline 6 HEI distributor. To make it computer controlled I removed the stock ignition control module, vacuum advance and mechancial advance (welded the mechanical advance arms so they would not move) and wired in a 8 pin GM ignition control module that I removed from the vehicle I got the throttle body unit and harness from (a 91 Chevy K1500 pickup with 4.3L V6). The module would not mount in the distributor so I remotely mounted it on the passenger side inner fender (as you can see in the video).

The only sensors used are the
Throttle Position Sensor (TPS)
Idle Air Control Valve (IAC)
Manifold Absolute Pressure Sensor (MAP)
Coolant Temp Sensor (CTS)
Electronic Spark Control Module (ESC) used for the
Knock Sensor
Electronic Timing Control Module (ETC) used for timing
O2 Sensor

No cam or crank sensor is used in this setup. The computer uses the ETC module which sends a pulse to the computer when a plug fires. The computer also uses this pulse to know when to fire the injectors.



Im working on the tech tip and am almost done with it. Its getting to be a few pages long already but I wanted to fill it with as much info as possible.

[drummin89]

I worked on it a bit more today. Working out the bugs that come with doing something like this.

I believe its getting a bit more fuel than needed. It starts up nice, runs nice, revs nice but when I let it idle for a long period it starts to struggle. Nice thing about fuel injection is that it won't let the engine die. I took the air cleaner off and from the top you can watch the idle air control valve (IAC) coming to save the day. When the engine starts to see it struggle, it opens up the IAC and the rpms pick back up, then repeats and it continues to do this unitl I shut it off or rev it. Revs fine even when its doing this. Took the spark plugs out and they seem a bit wet, not horribly, but wet. The spark plugs are black, mostly because of the 4bbl. This week I'm going back to the u-pull-it yard and will pickup a 2.8L injector unit to see if it corrects the problem.

Also have to get a can of starter fluid to see if there are any vacuum leaks around the adapter plate I made to mount the TBI unit.

[drummin89]

OK, have a question. Can't quite tell from just watching, but I was wondering if the computer fires both injectors at the same time or one after the other or ???

I was thinking, what would happen if I unplugged one of the injectors? I still plan to try the 2.8 injectors, won't get to the yard until saturday though.

Anything else I should try from the 2.8?


Did a bit of researching and comparing of my wiring diagram to a 2.8L V6 diagram from a 88-92 s10 and the wiring is the same, so when I go to the yard for the injector unit, I am also going to pickup a 2.8L computer.

This leads me to my next question, do I also need a 02 sensor from a 2.8 or will the one I have work and what about the map sensor, grab one too?

[Daniel U]

Very cool mix of old and new!

[drummin89]

Ok did some more researching and thinking. The 3.1L which uses the same 2bbl tbi220 unit came in the 91-93 chevy lumina, 89-92 olds silhouette and 91-93 pontiac trans-sport. The wiring, like the 2.8 is also the same as the 4.3

I may buy at the yard 1 2.8 injector unit/pod, 1 2.8 computer, 1 3.1 injector pod and 1 3.1 computer and do some mixing and matching. A nice thing about the 3.1 computer is that it has a trigger wire for a cooling fan relay. Not sure if I should also get the 2.8 computer or not. The yard charges about $20 for computers. 3.1 is probably a bit closer than the 2.8 and the fan relay trigger is a plus.

I can try a few different combinations
4.3 computer with 2.8 injector pod
4.3 computer with 3.1 injector pod
3.1 computer with 3.1 injector pod
3.1 computer with 2.8 injector pod
3.1 computer with 4.3 injector pod
2.8 computer with 2.8 injector pod
2.8 computer with 3.1 injector pod
2.8 computer with 4.3 injector pod

anyone know or can get the specs on the 2.8, 3.1 and 4.3 injectors

not sure what sensors and that will interchange, I imagine the IAC, TPS and CTS won't make a difference, MAP might need to be changed and MAYBE??? the O2 sensor.

I also read somewhere that the vac port on the MAP must be pointing down. TRUE?

[drummin89]

OK a little update

I changed out the 4.3 injectors for 3.1 injectors and the stumble/struggle at idle was less frequent. IAC still has to save the day and keep it from stalling, but not as much as before. BUT (and I found out something by using a computer tuner) when the engine starts to warm up and gets around 130degF the computer wants to start to lower the idle rpm from 1000/900 to 600. When it starts to do this, the engine struggles and stalls. Im still guessing to much fuel.

I have a few more things Im going to try and then Im taking the leap to MS. I want to try the 3.1 computer as well as the 2.8 injectors. Im not positive that these will fix it but I have to try.

Ive been talking to EFI-DIY about the MS system and will be buying the unassembled kit and the 746/747 adapter board if the above don't work. Nice thing about the MS is if I ever switch to a different engine (inline of coarse) the ms is adaptable. Total for the MS system comes to about $400.

[drummin89]

Set the timing to zero (pointer and ball bearing on flywheel match up)

Installed the 3.1L computer and left in the 3.1L injectors. Let it idle until it got up to around 190 degrees and actually did better than I expected. Has a slight fluctuating idle but not bad. Idles around 800. The next time I have a chance Im going to experiment a bit more. Plan is to try both the 4.3 and 2.8 injectors with the 3.1 computer and see how it goes. Still wondering about the 261 running better with a 4.3 computer and 5.0 injectors. Maybe I will have the same outcome with the 3.1 computer and 4.3 injectors.

will see!!!

[drummin89]

The Throttle position sensor checks out fine, the map sensor I'm not quite sure on. I get 5.1 volts across terminals A (sensor return/ground) and C (sensor 5v reference), which seems correct. Across terminals A and B (sensor signal to computer) I get like 4.2 volts. Across terminals C and B I get about .3 volts. All this is with the key ON and engine OFF. From the testing procedure that I got off of a automotive repair site, this is backwards.

I have to test the IAC valve yet.

More than likely I will just end up purchasing a new MAP sensor anyways and getting a few IAC valves at the local yard.

[eventytoo]

Wow looking good

A few things

1. Whats your voltage durring crank- run are you using a relay? Its no less than 11.2 volts. Any less that 7 and it wont run.
2. Your ground cables are also big.. form battery to motor motor to cab cab to frame then frame back to motor.
3. Take an ohm meter and check the housing of the o2 sensor to the header. There should be no resistance the o2 sensor
needs to be grounded for it to work correctly.
4. Do you have any vacuume leaks? Are you shure? Are all your vacuume lines not in use pluged?
5. Your tps what is it set at at engine off full water tempature. Did you ajust this and tamper with its setting?
6. Your distributor you modifyed to make it work. When your setting the timing there should be no advance at all
from 1000rpm to redline. If your getting advance your not setting it correctly. Also im not shure if your to set it at O btdc.
I always assumed that it was 10 deg btdc but the timing marks wold say 0 and align on lets say a 4.3 5.0 and 5.7.
7. Your map sensor this is the most important of them all If it is not working correct everyting will be incorrect. You ask
if the position matters? YES it should be mounted is the stock position. Also if your using another port then what it was in
orignaly you will have problems. Do Not run a tee off the map sensor to lets say a vac gague. Also of your not using the
stock size and legnth vacuume hose you will have problems.
8. The coolant temp sender is it in good shape is it within book specs. The cold fuel enrichment relys on the sender.
The t-stat should be 20deg. Higher than when cold fuel shuts off and goes into normal mode.

"when the engine starts to warm up and gets around 130degF the computer wants to start to lower the idle
rpm from 1000/900 to 600" This is cold fuel pulling off.

9. Do you have an air fuel ratio gauge? A vacume gauge?
10. What fuel pressure you got?
11.The injectors should be firing at the same time. A meter should tell you.

12. Your connector to the power side of the hei distribitor is an oe syle
snap in one. You kill the spark and not the fuel you will have major issues.
It will think its killing off and will poor fuel like no tomorow. I speak first hand
on this one. Watcing a hot gas engine diesel backwords not cool.....

The ecm is set up into cells invac @ rpm. One major key is the camshaft. You inline 6 may have different vacuume at blank rpm
and blank invac compaired to what you can get off the ecms your trying. Also weight of car to a truck gear ratio ect.
This is why without a custom tune your not gaining much over a carb.

All I can say is if you have a poor setup to begin with ( fulty sensors, leaks, incorrect wireing, poor timing, incorect tps ajust. ect)
You will never get it to run right. No matter what injectors stock computer or even a custom tune if the base calabraton is not correct it will
be like putting jam over moldy bread.

[drummin89]

1. I will check the voltage during crank when I get time. The starter solenoid gets activated through the starter post on the ignition switch.

2. Battery cable from battery to bellhousing is 4ga, from there I have 3 8ga ground wires, 1 to each frame rail and 1 to the cab.

3. I will also check to make sure there is 0 resistance where the O2 sensor is mounted.

4. I am pretty sure I have no vac leaks, at least not around the TBI unit to the adapter plate and the adapter plate to the intake. I sprayed starting fluid to see If I get a rpm change and all was fine. The only vac line off the intake is the one for the MAP. All unused lines are plugged.

5. TPS I did not touch at all.

6. The initial timing was set (with the bypass connector disconnected) to where the pointer on the bellhousing and the ball bearing on the flywheel line up. This is 10deg btdc

7. I will remount the MAP sensor so the vac port is pointing down. The vac line to the map goes directly to the map from the same port the donor vehicle used. Nothing tees off anywhere on that line. Size and length is correct.

8. Coolant temp sensor is new

9. Im looking at purchasing a Innovate Motorsports LC-1 wideband O2 sensor kit that also comes with a tuning/datalogging software so I can view what the sensors are sending back to the computer.

I have a vac gauge just need to hook it up.

10. Fuel pressure unknown. Pump is a new Carter P50001 external pump made for TBI systems. Feed line is 3/8", return in 5/16', just like donor.

Once I get the wideband O2 sensor kit and the datalogging software I should be able to see what is going on.

[yodi]

was wondering how u got the CPP power steering to work on ur 235, im pretty sure that they only work on V8's but i may be wrong. did u have to make any modifications to the pulley system? where on the straight six block did u put the pump/reservoir? i really want to install power steering on may GMC 270 straight six. thanks for the help

[drummin89]

came up with my own set of brackets to mount the pump where the gen/alternator was and then moved the alternator above the pump.

http://i175.photobucket.com/albums/w...p/100_0563.jpg
http://i175.photobucket.com/albums/w...p/100_0618.jpg
http://i175.photobucket.com/albums/w...p/100_0882.jpg
http://i175.photobucket.com/albums/w...p/100_0883.jpg

[drummin89]

These brackets work for 216 and early 235's, I'm currently working on designing brackets for someones 261 which will also work for later 235's.

Send me some pictures of the engine and I will see what I can come up with.

[yodi]

hella cool!!! looks hard and time consuming tho

[drummin89]

Not all that it looks. Some initial measurements and about 20 minutes on autocad. About another 10 and I get these.
http://i175.photobucket.com/albums/w...pbracket-1.jpg
http://i175.photobucket.com/albums/w...verside3-1.jpg

[yodi]

i dont have any pictures right now, but i think that all the GMC blocks are pretty similar to the chevy blocks, but again couldn't be sure

[yodi]

how did make the pulley system work out?

[drummin89]

Pulley system???

I will try to answer anyways....The power steering pump runs on the same belt as the crank and water pump. The alternator runs off the second groove of the power steering pump pulley. First I measured the length needed for the main belt (p/s pump, water pump and crank), bought and installed the belt and then measured for the alternator belt, bought and installed that. So far its staying quiet.