North American Turbocoupe Organization



Struggling under boost
Liquid_force Offline
Senior Member
#1
My '88 has been running relatively well, and I believe (I'll double check at lunch today) that it does fine as long as it's not good and hot.

The problem is, especially at highway speeds, is that when I get into it, it refuses to respond whenever the boost gets above 8-10 lbs. It just bogs down and won't even maintain it's speed. The temp guage never gets terribly high since I've wired in a manual fan switch, but as long as it's good and warmed up there's just no power under boost. Am I just going to have to deal with it until the end of summer?
88 TC -- Dark Blue 283k
RIP - 9/22/07
She was a great TC and went down swinging Smile
Now -- Me: A minivan, I'll spare you the details.
Her: '09 VW Tiguan AWD 2.0T 101k
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segfaultxr7 Offline
Posting Freak
#2
Have you checked for any codes yet? Done a Motorcraft tuneup lately? When I had this problem, it was a combination of a bad TFI module and fuel pressure regulator. The FPR is easy to check, just take the vacuum hose off of it, if it smells like gas it's bad. Does your tach needle jump around when it loses power? If so it's definitely an ignition problem, probably the TFI. The needle doesn't have to jump around for it to be bad though. Also, do you hear any noises like air escaping? Check your intercooler hoses, a lot of times people with leaky hoses say the car falls flat on its face after 5-10 psi. Good luck!
88 TC 5-speed
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Pete D Offline
Administrator
#3
pull the codes, check the I/C hoses and if that doesn't get it do a complete fuel pressure check. Smelling the line to the FPR is only part of it. I can send you the fuel sys diagnostics if you need them.

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NATO Member. it's not a vice, it's an obsession
"The nice thing about each new day is nobody ever used it before" Barnaby Jones
88 TC X 2, 86 SVO, mods list at
http://www.turbotbird.com/showroom/pd_88tc.htm
Pete Dunham


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Liquid_force Offline
Senior Member
#4
Well, since the initial problems under boost it seems to have gotten worse. I was on the highway last weekend and with the a/c on it wouldn't maintain 70mph. I had the cruise set and as soon as the boost gage came off zero the motor would start to stumble. After I ran out that tank of fuel it did better on the new tank, but still having problems at 8 psi or so. At least it will maintain speed on the hiway now though.

The FPR was new a couple summers ago. Fuel filter is like 6 mo. old. I guess I'll see if I can get anything from the codes.

BTW, someone suggested the KS. Is that a possibility?

[This message has been edited by Liquid_force (edited 09-03-2002).]
88 TC -- Dark Blue 283k
RIP - 9/22/07
She was a great TC and went down swinging Smile
Now -- Me: A minivan, I'll spare you the details.
Her: '09 VW Tiguan AWD 2.0T 101k
Reply

Pete D Offline
Administrator
#5
I doubt that the KS is a problem. One thing it could be is an exhaust restriction like a clogged cat. However a clooged cat can make it run hotter while not allowing the engine to breath enought so power falls off. Check the fueel system and then put a vacuum gauge on it. You should see 18-21" at idle. Manually operate the throttle and take it up to around 2000 rpms. Release the throttle so that it closes quickly. The needle on the gauge should instantly jump to 20+. If the needle hesitates before jumping up, that's a sign of an exhaust system restriction.

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NATO Member. it's not a vice, it's an obsession
"The nice thing about each new day is nobody ever used it before" Barnaby Jones
88 TC X 2, 86 SVO, mods list at
http://www.turbotbird.com/showroom/pd_88tc.htm
Pete Dunham


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Liquid_force Offline
Senior Member
#6
Quote:Originally posted by Pete D:
One thing it could be is an exhaust restriction like a clogged cat. However a clooged cat can make it run hotter while not allowing the engine to breath enought so power falls off.

It just hit 194k and has the original cat. Also, it was reading a little warmer than usual over the weekend.
88 TC -- Dark Blue 283k
RIP - 9/22/07
She was a great TC and went down swinging Smile
Now -- Me: A minivan, I'll spare you the details.
Her: '09 VW Tiguan AWD 2.0T 101k
Reply

GARNET88 Offline
Senior Member
#7
Mine did the same, under boost she would fall on her face!!! My first bet was no fuel...... I was wrong she was to ritch. I later found it to be the door in the VAM was stuck open thus giving me the ritch condition.Good luck! P.S. mine also got worse over time

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NATO Member
88 TC + a killer driver= one bird that can't be stoped!
2.5 in. side pipe exhaust with no muffler, K&N cone filter, Gillis set to 18 PSI...= the loudest TC knowen to man!It is time to build the Bitch of all 2.3's!!!!!!!
1988 Turbo Coupe
2.5" Stainless exhaust. Duals with flowmasters.
House of Kolor paint by: Glen Gordon
ROH Wheels
Lowered
Front Mount IC
Turbo Smart BOV
Gillis Boost valve
K&N
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bigred Offline
Member
#8
Look to see if turbo is glowing after driving awhile. If it is drop the down pipe and see if that helps. I had same problem and cat was clogged

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1988 TC T-5 swap,New Head,
Ranger Roller Cam,New brown tops.
3" cone filter(spectra)
,boost Set at 18 psi,No Knock sensor.
New 3"cat and 2.5 duals.
1967 F-100 Ranger short bed 352/2 barrel
1969 Pontiac LeMans
1988 E-350 Cargo van 351/C6
2000 Explorer 4.0 auto

[This message has been edited by bigred (edited 09-04-2002).]
1988 TC T-5 swap,New Head,Wiseco .030 pistons ,5.5 Crower rods ,balanced ,24x12x3 intercooler,T-3 .60
Ranger Roller Cam,New brown tops.
New 3"cat and 3"single SS exhaust
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Liquid_force Offline
Senior Member
#9
Quote:Originally posted by bigred:
Look to see if turbo is glowing after driving awhile. If it is drop the down pipe and see if that helps. I had same problem and cat was clogged


That sounds like an idea. Must be one LOUD ride though.

The car runs just fine as long as I'm not into it hard. As soon as that boost gage gets to 6 or 7psi there's just nothing there.
88 TC -- Dark Blue 283k
RIP - 9/22/07
She was a great TC and went down swinging Smile
Now -- Me: A minivan, I'll spare you the details.
Her: '09 VW Tiguan AWD 2.0T 101k
Reply

Liquid_force Offline
Senior Member
#10
Quote:Originally posted by GARNET88:
Mine did the same, under boost she would fall on her face!!! My first bet was no fuel...... I was wrong she was to ritch. I later found it to be the door in the VAM was stuck open thus giving me the ritch condition.Good luck! P.S. mine also got worse over time

I just ran codes...

Koer: 25(Yeah, I know), 73? and 76? does that mean I didn't give it enough throttle during the dyn. test? I ran it up to 3500.

Koeo: Cur. Fault: 85? 88?
Cont. Mem.: 27? 41, 42

Should I look into the VAF?
88 TC -- Dark Blue 283k
RIP - 9/22/07
She was a great TC and went down swinging Smile
Now -- Me: A minivan, I'll spare you the details.
Her: '09 VW Tiguan AWD 2.0T 101k
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