84 2.8 die's when tilted

Hi guys, the wifes new 84 2.8 auto trail xj stalls when it tilts to the left, hard to restart, blows out some black (rich) exhaust when it fires up, after we get it level...dont have a lot of experience with these carbs, if thats the issue. Gotta have it fixxed up right for tellico next year...first time testing it today, RE lift, not sure what size, was on the jeep when we got it, previous owner had 33" swampers on it, 31"s fit just right if you ask me..

The Rochester 2SE carb (or the CA version E2SE) is a complicated POS. It was prolly OK for citations and camaros, but it can't take the extreme angles of wheeling.
This is true of a lot of carbs.

The float is hinged on the left/outside of the bowl. When the vehicle tilts left, the fuel sloshes to the left in the bowl and the float drops thereby allowing the needle to continue to fill (overfill) gas into the bowl and flooding the engine.
The puff of richness on restart is the 'flooding' gas in the manifold burning off.

Over time, your float has probably bounced so much that it is bent and cutting off fuel too late.

Correction:
When the carb is rebuilt (kits were still available at AutoZone 4 years ago when I did mine, ~$20 IIRC), it is extremely important to adjust the float level to the PRECISE setting of the instructions. Even a tolerance of something like +/- 0.015" (1/32 inch) could be too much.
You could try to open just the top of the carb and adjust the float, but be careful! If the gasket tears even a little (and I estimate *90% chance that it will), then you need a kit for a new gasket.

One of the greatest advantages of FI in an offroading engine is that it isn't affected by gravity like a carb.

-Rick

thanks for the advise, I will check in to that this week, any other carbs that will bolt or adapt on? also did gm ever have a tbi for a 2.8 and if so how hard would that be to adapt?

www.webercarbs.com offers a kit specifically for the XJ 2.8, about $425 IIRC.
Holley has a 2bbl of the proper cfm (<300), but it, and ALL other american 2bbls TTBOMK are side-by-side, instead of inline progressive primary/secondary like the Rochester 2SE.

Neither the holley nor weber are 'feedback', so they are technically not emissions-approved for our engines.

At the same time that GM was selling carb'd-only 2.8's to Jeep, they were selling S-10's with FI (simple TBI's, I think).
There's a guy posting over in JU right now about the FI that he put on his 2.8; I think he's talking about a junkyard S-10 set-up.
This would meet EPA regulations, since it's a newer version of an engine originally-offered for the XJ model.

Be sure to get all sensors (including O2 in the exhaust), wiring, intake manifold, distributor, and the 'puter.
I understand (but haven't seen) that the Smog Pump, and its tubing to your exhaust manifolds, are NOT compatible with FI (since it injects air into the exhaust and screws-up the O2 readings); you could keep your manifolds and plug them, or grab the manifolds from the donor.

Also, it might use a different catalytic converter, since I *think* our cat is single-stage (only unburned hydrocarbons are controlled) while *most* FI systems use a three-way cat to also control CO and NOx.

Hope this helps.
-Rick

I've been having this problem even on the street around corners. Found the TBI posts over there a few days ago and PM'd him about the set up. So far I have this much:

I am going to do a full write up on it when I get some time.... You will need the intake manifold, TBody, ECM and all sensors, etc. Plus, I bought a new harness from Painless Wiring.

Well, here is more stuff you will need:
A 90-93 2.8 S10 is a good donor.
Make sure when you pull the ECM, it has the service #1228062
The in tank fuel pump assembly for an 85-86 2.5 TBI XJ
The wiring is already there for the fuel pump power.
The ECM in the S-10s are behind the glove box.
Also get the vapor canister from said vehicle.
The same send/return lines currenly in your XJ are the same as the EFI model, but you will need to upgrade to "fuel injection" hose.
A weld in 02 sensor "bung".
Wiring harness from the donor truck, or you can buy one from Painless at around $280 (MUCH easier).
I will send more info as you need it!

This is from two different replys but you get the idea.

thanks all, will try to rebuild/recarb first but the FI option would be nicer...I'll see if I can pick up a donor vehicle for the whole set up.

The TBI idea is valid, or you could do the boneyard crawl and dig up the top end of a later 3.1 with PFI. Corsica, Beretta, Camaro, Firebird, and S10 should all be good to go. Hell, grab the whole engine while yer at it!

The 2.8, 3.1, and 3.4 are all the same physical size and mechanically the same, but the FWD and RWD drive versions are a little different. If you get the whole engine, make sure it's RWD. Top end stuff will swap.

5-90

5-90 said:

The TBI idea is valid, or you could do the boneyard crawl and dig up the top end of a later 3.1 with PFI. Corsica, Beretta, Camaro, Firebird, and S10 should all be good to go. Hell, grab the whole engine while yer at it!

The 2.8, 3.1, and 3.4 are all the same physical size and mechanically the same, but the FWD and RWD drive versions are a little different. If you get the whole engine, make sure it's RWD. Top end stuff will swap.

5-90

Click to expand...

I think the SFI setup needs the timing case for the CPS located lower driver side; no casting to receive it in the carb'd versions.

Come to think of it, theTBI prolly needs this, too.

Fine, grab those too.

Another idea - the Megasquirt DIY Universal Fuel Injection Controller as put out by Bowling & Grippo. Yahoo! has an egroup on them as well (groups.yahoo.com/group/megasquirt, IIRC.) There are people using them as dedicated system controllers and as additional fuel controllers for forced induction, and everyone seems to be REALLY happy with it! I don't know that much about it (I've only just tuned in myself) but there's a wealth of information to be found just for the searching...

5-90

yellowxj.....

B4 doing the FI swap on the 2.8 I would serouly consider a 3.1 or 3.4 swap. If you have to get a doner for the 2.8 FI then why not just get a different doner? Plus the 2.8 was scrapped and redesighned for a reason. It was and is plagued with other problems besides the carb. One being oiling issues. And after you buy a 2.8 donor S-10 (which on ly came with the 2.8 by the way) you could get a junk commaro or firebird witha much better engine and newer. I looked at a 3.4 in a 94 cammero ot one time. Just food for thought. The easyest is the Weber by far!

Thanks all, I could get a 3.4 from the local yard for $550 but her 2.8 still seems solid, the motor has definitly been out before so maybe it was rebuilt once already. Seems like the carb might be the original(2??K) so it might be time for a new one. I'll try the rebuild kit first. I can also get 2bbl holleys pretty cheap (lots of guys I know race with them) do you think a holley could work with the intake? Did the 2.8's ever come with the HEI distributor?

yellowxj said:

I can also get 2bbl holleys pretty cheap (lots of guys I know race with them) do you think a holley could work with the intake?

Click to expand...

The bbl arrangement of the 2SE carb is inline, with primary venturi forward and secondary aft.
It's like a four barrel cut down the middle.
The bolt spacing is about 3" side-to-side at front, 2.5" side-to-side at rear, and about 5" front-to-back.
This doesn't seem to match Holley/Carter square, Spreadbore, Q-jet, or Thermoquad patterns.

This doesn't bode well to fitting a holley 2 bbl, which has conventional american side-by-side bbls on a single throttle shaft.
I doubt if the holley can be rotated 90* and run both barrels at once, because of the odd bolt pattern.
One advantage of progressive linkages (primary-secondary) is that the air flow thru the primary is optimized for low-to-mid throttle response, and that's where a low-speed 4wheeler needs the torque.

There's NO room vertically to install an adapter (unless the holley is significantly lower/shorter than the 2SE).

BUT,
Edelbrock makes a manifold.
It has a generic 'base section' that bolts to the heads; ($160, PAW catalog fall '97)
There are two 'top sections' available, each is about $85, PAW catalog fall '97)
* One fits the 2SE carb.
* The other fits 4bbl carbs with holley square pattern.
** This would work with the 'baby' Holley #0-6299 4bbl 390cfm carb ($386, PAW catalog fall '97), or any low cfm rebuilt 4bbl square pattern carb.
Note: The factory 2bbl manifold flows very well, and the edelbrock (in 2bbl form) doesn't flow significantly better.
160 + 85 + 386 = 631 > weber at $425.