1997 Ford Escort SLUGGISH ACCELERATION, POOR MILEAGE, FLAKY

Tiny
SMIRSHKAHOVEN
  • MEMBER
  • 1997 FORD ESCORT
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 49,000 MILES
This car recently had new muffler installed. Sluggishness from dead stop noted shortly after along with what almost sounds like an exhaust leak in the front end - returned to shop and no leaks found. Once up to highway speed, car runs fine, however once warm the car idles rough (surging) when at a stop. Turning the A/C ON cures this problem so long as the fan runs (30 seconds). When the fan shuts off, rough idle returns. This rough idle sounds like a cycling 1 second surge in RPM. Rrrrrunh, rrrrrunh, rrrrrunh

New plugs, wires, fuel filter, PCV, serpentine belt installed. Sluggish acceleration improved, but could be better. Rough idle after warm-up continues.

Temp gauge flaky, accurate when working, but cuts in and out. Seems to be affected by acceleration and shifting between gears. Either reads correctly or not at all. This is a fairly constant state, IOW it fluctuates every few seconds rather than minutes or days.
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Tuesday, September 29th, 2009 AT 12:14 PM

10 Replies

Tiny
MERLIN2021
  • EXPERT
Get a can of spray Throttle body cleaner, start the car and spray around, pay attention to vacuum lines and manifold, if the idle changes, you found a leak. You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs!

The other possibilty is the idle air control, it, s bolted to the side of the throttle body.
How much of the exhaust system was replaced? Is check engine light on?
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Tuesday, September 29th, 2009 AT 1:12 PM
Tiny
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I have cleaned the IAC. It made no difference that I could tell.

The muffler, tailpipe and the s-shaped pipe leading to the muffler were replaced.

Will try the throttle body cleaner (can't use it in the throttle body though, according to a warning label at the intake).

Check engine light is not on.

Car has never stalled, by the way.
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Tuesday, September 29th, 2009 AT 1:21 PM
Tiny
SMIRSHKAHOVEN
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Does not appear to be vacuum leak. The surging idle doesn't change at all.

Since the car was warm already, it did display the idle from starting.

Don't forget the temperature gauge fluctuation.
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Tuesday, September 29th, 2009 AT 1:31 PM
Tiny
MERLIN2021
  • EXPERT
They now make a throttlebody cleaner, not carb cleaner, I now ford uses teflon coated TBI's but the newer TBI cleaner will not harm it! As for the Gauge, check the connector at the sender #33 in the diagram.
Is your check engine light on?


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It might be worth your while to go to a different muffler shop/ garage, sometimes when mistakes occur, they hide the errors!
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+1
Tuesday, September 29th, 2009 AT 1:51 PM
Tiny
SMIRSHKAHOVEN
  • MEMBER
Check engine light NOT on.

Will check the temp gauge connector now. Hard to see 33 though. Front of coil?

Just got back from a 20 minute run - heat blows hot, A/C cold, surge doesn't immediately start upon coming to a stop, there is a 15 or so second delay.

Gauge connections seem fine. Gave it a shot of DeOxit in case. Made no difference. But, gauge reads about 1/4 of the way to hot when it reads at all. Shifting gears while stationary drops it to no reading in reverse, otherwise it reads fine. Occasionally ticks downward. A different behavior than when driving, when gas pedal seems to have most effect.

And I didn't mean to confuse the issue with the muffler, but the gauge was already flaky before that and the idle may have been too. I always drive with the A/C on, so it was only when my non-A/C inclined wife drove that this issue came to light.
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Tuesday, September 29th, 2009 AT 1:57 PM
Tiny
MERLIN2021
  • EXPERT
Start engine, turn A/C off warm to operating temp, does the cooling fan(radiator) come on? Turn A/C on, fan should start with compressor. Ford recommends replacing thier IAC's, not cleaning them.
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Tuesday, September 29th, 2009 AT 2:34 PM
Tiny
SMIRSHKAHOVEN
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Yes, fan runs when A/C is on and it runs with A/C OFF if I let it sit and idle for for a while (most of our trips are short).

I know that Ford recommends replacing the IAC, but we are talking less than 50k on the car. I don't know how dirty these get, but it looked pretty spotless before cleaning and nothing that looked like grime was removed.

Do you think IAC is the culprit? More likely than EGR or possibly CTS?

BTW, I just pulled the vacuum line from the EGR while idling in park. The car did not stall. Clue?

Also, wife informs me she has seen a check engine light in the past (she can't say when - perhaps more than once), but it went out on its own. ?
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Tuesday, September 29th, 2009 AT 2:51 PM
Tiny
MERLIN2021
  • EXPERT
Let's try this, measure the resistance of the IAC:
IDLE CONTROL SYSTEM 1. Check Idle Air Control (IAC) Solenoid Resistance Turn ignition off. Disconnect IAC wiring harness connector. Connect DVOM positive lead to VPWR (White/Red wire) terminal of IAC solenoid wiring harness connector. Connect DVOM negative lead to IAC terminal. If resistance is 6-13 ohms, go to next step. If resistance is not 6-13 ohms, replace IAC valve assembly. 2. Check IAC Solenoid Internal Short To Case Turn ignition off. Measure resistance between each wiring harness connector terminal and IAC housing. If either resistance is less than 10,000 ohms, replace IAC solenoid assembly. If each resistance is 10,000 ohms or more, IAC solenoid is okay. If fault is still present, go to CIRCUIT TEST KE in TESTS W/CODES article for additional testing.
Let me know...and ECT(CTS)


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No Stall? It should not stall unless you apply vac at idle, this makes the EGR open, if it does not stall with EGR active, then carbon blockage is your answer, remove EGR and clean out the port under it all the way to the throttle plate, I use a coathangar for this, and TBI cleaner, clea EGR valve too, apply vac to the EGR, does the diaphram move? Could be loosing vac at EGR.
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Tuesday, September 29th, 2009 AT 3:01 PM
Tiny
SMIRSHKAHOVEN
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The first test gives me 11 ohms.

On the second, from one of the two terminals to the housing I get 9500 ohms, the other reads 0.

Let me say, my meter may not be 100% accurate, but I think it's close.

Did you catch my update to the last message regarding the EGR?

Thanks for sticking with me through this.
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Tuesday, September 29th, 2009 AT 3:20 PM
Tiny
MERLIN2021
  • EXPERT
Could be faulty, just barely! Will get worse before it gets any better. I did answer your question about the EGR, You need to apply vacuum at idle to open the egr, removing it does nothing! If it dosent stall or idle way down with a hand held vac pump, then it is caboned. EGR has no vac supplied at idle. Egr solenoid(EVR) has an electrical connector and two vac lines to it. Shuts off vac at idle and cold operation.
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Tuesday, September 29th, 2009 AT 3:43 PM

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