North American Turbocoupe Organization



2.3T running terrible when warm...
Thill Seeker Offline
Junior Member
#1
Hello everyone, new poster long time reader here. I recently acquired a 2.3T swapped car. I honestly think it's got a good amount of potential but at the current moment no so much.

On a cold start, it's great. Very smooth and boosts well.. But once warmed up the idle bounces around a bit and driveabilty is pretty poor, not smooth at all. The car littlery bucks around.

First thing I did was gap the plugs at .30, that helped a little but not much. The car has a FP gauge inside and it's reading around 41psi while the car is idling (with vac line on). From what I've read that's about right.

I'm also trying to figure out what parts are on the car. So far I've figured out it's a '88 Turbo coupe motor, volvo FMIC, 255lph pump, kirban adjustable FP regulator, adjustable cam gear, 35 pound injectors (brown tops), 3G alt, big VAM and a LB3 computer.

Here are some pics, to help:
http://i9.photobucket.com/albums/a87/pay...G_0502.jpg
http://i9.photobucket.com/albums/a87/pay...G_0504.jpg
http://i9.photobucket.com/albums/a87/pay...G_0505.jpg
http://i9.photobucket.com/albums/a87/pay...G_0506.jpg
http://i9.photobucket.com/albums/a87/pay...G_0498.jpg
http://i9.photobucket.com/albums/a87/pay...G_0508.jpg
http://i9.photobucket.com/albums/a87/pay...G_0510.jpg

Also a video showing how poorly it drives:
http://s9.photobucket.com/albums/a87/pay...G_0512.mp4

I've pretty much narrowed it down though.Came home from work last night and hopped in the car and took it around the block. Ran perfect! UNTIL the engine bay (and motor, temp was at 125 and coming up) got some heat into it then it started running like crap with bucking and all. So if I had to take a educated guess, I'd say it's something dealing with spark (wires/cap/rotor, coil, TFI module). Something heat-sensitive.

I also did a little digging earlier and found the ECT sensor (in the upper intake near the FP regulator) was disconnected. So I hooked it back up and I undid the battery for now to let the computer reset. I'll go outside in a bit and see if that did anything.

Please post up if you have some incite on this problem!

-Mike
-'91 Mustang w/ '88 TC motor... The daily
-'88 Mustang w/ T-70'd 5.0... The race car
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Pete D Offline
Administrator
#2
ECT is in the lower intake , in between the middle two fuel injectors. A bad ECT does not always set a code. There are no sensors in the stock 87-88 upper intake. There are a couple on the throttle body.

Have you pulled the codes from the EEC. What are the code numbers, for each section of the test?
Pete Dunham


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Thill Seeker Offline
Junior Member
#3
Quote:Originally posted by Pete D:
ECT is in the lower intake , in between the middle two fuel injectors. A bad ECT does not always set a code. There are no sensors in the stock 87-88 upper intake. There are a couple on the throttle body.

Have you pulled the codes from the EEC. What are the code numbers, for each section of the test?
Sorry, dunno why I said upper. But yea the ECT sensor in the lower, between the two injectors.

I pulled some codes with it KOEO:

81
83
85
88

I actually just went outside and hooked up the battery and low and behold it runs 100x's better. Doesn't buck or anything now. I rechecked for codes but still get those same 4. One of the codes is for a shift soloniod I think, the computer is from a auto TC but the car is a 5 speed.

I did feel a SLIGHT miss nearing the redline (6k)and the wideband is reading 10.0:1 while WOT, but other then that it drove perfect and made 15psi.
-'91 Mustang w/ '88 TC motor... The daily
-'88 Mustang w/ T-70'd 5.0... The race car
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Pete D Offline
Administrator
#4
81 is a problem with the stock boost control solenoid. Is your uunplugged electrically?

83 relates to the cooling fans. Circuit is open

85 relates to the auto trans.
Pete Dunham


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Thill Seeker Offline
Junior Member
#5
Pete, for 81 it is. I have a MBC. 83 I have a aftermarket electric fan, and for 85 like I said I have the LB3 computer from a auto TC.

Ok, just fired it up again and it's back to bucking and missing.

What should I set fuel pressure at? How do I do it on the 2.3T? Disconnect the vac line while it's running?
-'91 Mustang w/ '88 TC motor... The daily
-'88 Mustang w/ T-70'd 5.0... The race car
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Paulie Offline
Banned
#6
Check FP and make sure the cat is not plugged. More than likely you have no cat!! Check the timing and make sure it advances. And also check the compression.

FP should be 40 with the vacuum unhooked. Also check spark energy and the wires. Cap and rotor. Alo check the PCV VALVE. Also check the TPS and VAM for a good voltage sweep. Also check for vacuum leaks and boost leaks. Good luck
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Thill Seeker Offline
Junior Member
#7
Quote:Originally posted by Paulie:
Check FP and make sure the cat is not plugged. More than likely you have no cat!! Check the timing and make sure it advances. And also check the compression.

FP should be 40 with the vacuum unhooked. Also check spark energy and the wires. Cap and rotor. Alo check the PCV VALVE. Also check the TPS and VAM for a good voltage sweep. Also check for vacuum leaks and boost leaks. Good luck
I checked the FP, makes right at 40psi with vac on at idle. It does have a cat, it's not plugged though. How would I check spark energy and the wires? Cap had some corrosion in it, so I cleaned it up and it seemed to help. Rotor looked good. I haven't checked the PCV valve, will do that. TPS and VAM are good. Car makes 25inches of vac at idle, and it's very quiet under the hood at idle.
-'91 Mustang w/ '88 TC motor... The daily
-'88 Mustang w/ T-70'd 5.0... The race car
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Jeff K Offline
Administrator
#8
40 psi with vac line ON FPR is WAY out of spec on the high side. FP should be 39-40 psi with vac line OFF. With vac line off, this will not change with RPM, load, etc. Depending on idle vac, with vac line ON FPR, press should be around 30 psi.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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Thill Seeker Offline
Junior Member
#9
Quote:Originally posted by Jeff K:
40 psi with vac line ON FPR is WAY out of spec on the high side. FP should be 39-40 psi with vac line OFF. With vac line off, this will not change with RPM, load, etc. Depending on idle vac, with vac line ON FPR, press should be around 30 psi.
Wow, I thought it was 40psi with the line on. I'll change that ASAP. On the 2.3T cars, you adjust it while idling correct? Would you plug the line or just leave open as a vac leak?
-'91 Mustang w/ '88 TC motor... The daily
-'88 Mustang w/ T-70'd 5.0... The race car
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SHOcoupe Offline
Member
#10
Check your ignition. I recently had the exact same issue with my Tbird.

The problem was plugs and wires.
I had aftermarket plugs and wires, and these engines are already very sensitive to spark.
Once the wires heated up, I couldn't boost more than 12psi without it bucking and missing.


I bought BRAND NEW Motorcraft plugs (gapped to .029) and Motorcraft wires (bought 5.0L wires because they have the angled boots), and now it runs perfect.

If your wires are too close to the turbo or header, then you will have problems (heat = resistance).

I ended up spending wayyy too much money chasing down a simple problem (new ECU, ECT, ACT, checking for leaks, dissy, cap, rotor, tfi).
88 TC, FMIC, GT35-1 .70 A/R, 42lb Injectors, MS2 p&p, Custom upper manifold, junk heap Stinger header, 3 inch exhaust, Accufab FPR, Bo-Port 1.9 cam, Oversized valves, ported head, Stage 3 clutch, 22psi.
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