First drive and help needed on various issues

Stock FSJ Tech Area

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

First drive and help needed on various issues

Post by yuza »

Hi all,

I finally got the Chief back from the workshop after installation of a new clutch kit & new tires
First drive after purchase (2 months back) and several questions/helps immediately popped up!
I tried searching the forum and found only few topics related to the them, therefore forgive me if I open a new thread
It is a 1979 Chief, 4.2L with manual transmission

1) gas pedal is very hard, and not helping a smooth drive. I am used to drive-by-wire with my main car, so my right foot probably needs some re-learning, but I wonder what to check/replace to make it smoother

2) 4th gear engage makes a grinding noise (T176 transmission). Clutch is new as said, noise seems to come from the tower/selector than from the gearbox itself. Again, what to check?

3) instruments: just speedo and ammeter work, nothing else. I understood this may be due to several reasons but most common are poor ground and fuse, I have the workshop manual so I will start from there. Also downloaded the guide from Oljeep so I shall have everything I need to fix it

4) engine is running very rich, I can smell petrol at any speed! I guess a carb cleanup and ajustment is needed, maybe also a new air filter...

More to come, I just drove it 15km so far, but I can't wait to drive it again!

Thx
1979 Cherokee Chief 4.0L powered

PossumJr
Posts: 103
Joined: Fri May 10, 2019 8:04 am
Location: Eastern NC

Re: First drive and help needed on various issues

Post by PossumJr »

3) Since you already know to check the TSM you're off to a good start, but it can be a little vague in some cases with the gauge cluster diagnosis so if you need any help chasing gremlins holler at me, just went through the same thing on my truck and got real familiar with things. My recommendation is to go straight to pulling the cluster to clean the PCB contacts and pins and the contacts on the cluster connectors regardless of what the issue is as 40 years is a long time for surface oxidation and crud to build up. Another common issue is the voltage regulator for all three of your dead gauges is known for having problems (it's built into the temp gauge).

4) Has the carb been replaced by a PO or has any of the emissions equipment been removed?
1979 J10, 360/QT

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

Many thanks for being willing to help, I appreciate
Yes the plan is to remove the cluster also because I need to glue the speed glass, now floating around!
I will report my findings and surely ask for more help

As far as I can understand from below the car, the exhaust was modded, no cat is present, just a silencer (not silencing a lot) and a straight pipe that os too short and throw fumes inside

Buying a stock exhaust makes no sense due to transport cost, my plan here is to just prolong the pipe

I had a talk meanwhile with the PO and he suggested to play with the front af screws and go leaner, might be worth a try...?

Mpg is unknown since the fuel gauge does not work but I assume it sucks!
1979 Cherokee Chief 4.0L powered

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

Oh, and yes he replaced the carb with a stock one from US, I might post a picture tomorrow if it helps
1979 Cherokee Chief 4.0L powered

letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: First drive and help needed on various issues

Post by letank »

yuza wrote:Oh, and yes he replaced the carb with a stock one from US, I might post a picture tomorrow if it helps
yes, post pict of the carb and the air filter assembly with the various vacuum hoses, the later air filter enclosure need some vacuum to keep a flapper opened, otherwise it will run rich.

viewtopic.php?t=13892

try to see if you have the right carb with the 1.08 stamped on the driver's side ( or the left side of the jeep, if you are outside the country, not too sure which one)

the gauges need ground, and the CVR is part of the temp gauge

viewtopic.php?f=10&t=8334
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
User avatar

fulsizjeep
Moderator
Posts: 5012
Joined: Sun Nov 06, 2011 7:21 am
Location: Fruitville, FL
Contact:

Re: First drive and help needed on various issues

Post by fulsizjeep »

Welcome to the full size fun. I take it you are not in the US. When you say T176 tranny, I wonder what you really have because that was not available until 1980. Can you share pictures?
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

ImageImage
1979 Cherokee Chief 4.0L powered

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

And here the pics of the carb
I couldn’t see any stamp or number on it
And air filter is mercruiser branded! Lol
ImageImageImageImageImageImageImage
1979 Cherokee Chief 4.0L powered
User avatar

fulsizjeep
Moderator
Posts: 5012
Joined: Sun Nov 06, 2011 7:21 am
Location: Fruitville, FL
Contact:

Re: First drive and help needed on various issues

Post by fulsizjeep »

Thanks. I meant pictures of the Jeep. From all 4 sides if you please.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

ImageImageImage
What I have on the phone, I can take more
Vin on the frame is J9, might it be that despite produced in 1979 it was a MY80?
1979 Cherokee Chief 4.0L powered
User avatar

fulsizjeep
Moderator
Posts: 5012
Joined: Sun Nov 06, 2011 7:21 am
Location: Fruitville, FL
Contact:

Re: First drive and help needed on various issues

Post by fulsizjeep »

Thanks. That looks good! It is not uncommon to see a year difference in Jeeps exported to Europe. Since this is left hand drive, it may not be an export. I am guessing it is an 80 or 81 despite the VIN. Starting 1980, they used T176 that mates to the NP208 transfer case and has a left hand differential on the front where the 1979 model was offered with T18 4 speed and Dana 20 transfer case which uses right hand side front differential. The rear axle for 80 and up would be AMC 20 instead of Dana 44. Also, those wheels are from 84-91 Grand Wagoneer.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

Yes diff is left hand on the front and right hand on the back.
So I have a Np transfer case and no dana44, thanks

So, back on instrument cluster, I just removed it
It looks ok, but few parts/wires seem missing (and someone has removed it already in the past)
Image
Image
A ground wire in the top left part (fan switch I guess) was disconnected
A couple of bulb holders are empy (are these bulb holders btw? What type of bulb should they get?)
Image
No hose connected to the fan/heating part, and nothing found behind the dash..is this wrong I guess..?
Image
Btw, when looking for lose connectors or flying wires, I noticed this below the steering column. Pink wire broken. What is this connected to?
Image

More to come tomorrow, thanks to everybody for help
1979 Cherokee Chief 4.0L powered

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

How can I test if my CVR works or not?
Or, if it is just a bad ground issue?
I am not too bad in mechanicals but a disaster in electricals...any easy way?
1979 Cherokee Chief 4.0L powered

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: First drive and help needed on various issues

Post by candymancan »

Pink is usually 12v power.red for these Jeeps. Since it looks torn on one end and cut on thr other. Id just reconnect the wires tbh. You do see the 2 ends in the pic right ?
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

PossumJr
Posts: 103
Joined: Fri May 10, 2019 8:04 am
Location: Eastern NC

Re: First drive and help needed on various issues

Post by PossumJr »

yuza wrote:How can I test if my CVR works or not?
Or, if it is just a bad ground issue?
I am not too bad in mechanicals but a disaster in electricals...any easy way?
In my case, I have a bench power supply which I used to verify function, but for most people it's probably easier in the vehicle for a so you have a source of 12 VDC. If doing it in the vehicle you will need to connect the red and yellow leads that went to the ammeter together as with that open there will be no voltage to the dash. You're going to need a multimeter and two jumper wires, as for the multimeter all you really need is a cheap analog one that can measure resistance and voltage, I think analog works best in this case. First make sure that you have continuity (low resistance) between the metal case of the temp gauge and the the ground pin. Reference page 1L-44 of the 1979 TSM for the cluster pinouts/connections. On the rear of the pcb you will see the three terminals of the temp gauge, each of which is labeled. S is input from the temp sender, A is 5V, I is ignition (12V). With 12V at terminal I and a good ground connection (you can use jumpers on pin E of the round connector for 12V, and the black wire on the rectangular connector for ground) you should see 5V at terminal A. There is a slight cavet though. The CVR is an electromechanical regulator; when it's powered a set of points vibrate to give an approximate 5V, it's far from a clean 5 VDC so using a digital meter on DC can give you some funny readings, this is why I suggest an analog meter (I had a brain fart when testing mine and never thought to try was using the AC setting to get a RMS value which might work well though). As long as you see a few volts even if in pulses, your CVR is likely fine (when I looked at mine my old Micronta meter showed regular pulses going from 4-6 volts when set to DC, your mileage may vary).
1979 J10, 360/QT

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

candymancan wrote:Pink is usually 12v power.red for these Jeeps. Since it looks torn on one end and cut on thr other. Id just reconnect the wires tbh. You do see the 2 ends in the pic right ?
I did cut one side before taking the picture
I'll try to reconnect and see what happens
1979 Cherokee Chief 4.0L powered

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

First drive and help needed on various issues

Post by yuza »

Ok I did the test you suggested and reconnected the pink wire below the steering column
Continuity between case of the temp gauge and ground pin on pcb is there
3A Fuse is ok
Red/yellow wires connected together
No voltage at pin A
Tested outside the vehicle with a motorcycle battery (positive to terminal I, negative from battery to tester, tester between battery negative and terminal A), I see 5V (battery is low in charge but still giving 7/8V)
And, measuring voltage out of pin E on the connector (key on, and negative to the black wire in the squared connector) I see no voltage at all
Does this mean I have no power to dash?
1979 Cherokee Chief 4.0L powered

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

I realized my tester is about to go, voltage reading is fluactating even when testing the car's battery, I need a reliable instrument to move forward
I plan to re-test everything and resolder the moving pins to exclude bad contact as a potential source of problems
I also need to understand what the POs have changed with regard to senders (coolant and oil) and wiring, since both seems different than what they should.
Oil pressure one has now a 2 wire connector and stock wire is disconnected, I wonder if it may even work now with the stock gauge...
Can anybody confirm what type of sender I should have and where they are located?
Oil pressure single wire just besides the oil filter?
Coolant temp on the left side of valve cover, again single wired?
Is the pink wire from the connector below the steering column (the one I just reconnected, see pics above) coming from fuel level sender?
Thanks
1979 Cherokee Chief 4.0L powered

PossumJr
Posts: 103
Joined: Fri May 10, 2019 8:04 am
Location: Eastern NC

Re: First drive and help needed on various issues

Post by PossumJr »

If the pink wire that is cut goes into the harmonica looking connector on the side of the steering column, then that is not related to the fuel sender, there are a couple pink wires on that connector that are in the light circuits. The fuel sender wire should come straight to the cluster out of the wiring harness I believe.

As for oil pressure there are two things down there by the oil filter. One is the two wire switch which goes to the choke on the carburetor, the other is the sending unit which has a single wire and looks like a metal can.

Temp sender screws into the intake manifold up front on the drivers side by the thermostat housing. Should only be one wire.

Provided they are all connected you can do a quick check by measuring resistance to ground from each of the sender inputs on the cluster connectors. Fuel sender is pink wire on terminal L on round connector, oil is third terminal on rectangular connector with purple wire, and temp is purple with stripe on terminal C on round connector (need to double check terminal lettering, but I think that's correct). Factory specs for the fuel sender calibration is 73 ohms at E, 10 at full; oil pressure should be around 70 ohms with 0 psi; temp will be 73 ohms at cold. That's not absolute, but 1 kohm plus means there's a problem somewhere.

Something I forgot to mention before, another quick check to get an idea if you can expect a gauge to function is measuring resistance from terminal to terminal referencing the values on page 1L-43 of the TSM. All the gauges here function using simple heater coils which heat up bimetallic strips, so if the coil is there and within resistance spec it likely will work.
1979 J10, 360/QT

Topic author
yuza
Posts: 130
Joined: Wed Mar 27, 2019 10:26 am
Location: Italy

Re: First drive and help needed on various issues

Post by yuza »

Thanks, will do these tests next saturday
Btw, in this pic tou can see my oil pressure sender
Image
1979 Cherokee Chief 4.0L powered
Post Reply