Stalling when cold
Freshman User
Joined: Jan 2003
Posts: 35
Likes: 0
From: Victoria Canada
Stalling when cold
Hi Guys.
I have a 1989 Bronco 5.8 and have the following problem:
- truck starts just fine when cold, but after 30 seconds, will stutter and stall when starting from a stop.
- after a few minutes and the truck warms up, the problem goes away and the truck works just great, although it will "surge" a little at very low speed.
- I've replaced the plugs, O2 sensor, dist. cap/rotor and PVC.
- the computer reported that the TSP was malfunctioning so I replaced it when I noticed that the wires were almost pulled out of it.
This didn't fix the problem.
- the computer now reports that the MAP sensor is faulty.
Any ideas here? I don't want to just keep replacing parts when they might be just fine.
thnx in advance.
I have a 1989 Bronco 5.8 and have the following problem:
- truck starts just fine when cold, but after 30 seconds, will stutter and stall when starting from a stop.
- after a few minutes and the truck warms up, the problem goes away and the truck works just great, although it will "surge" a little at very low speed.
- I've replaced the plugs, O2 sensor, dist. cap/rotor and PVC.
- the computer reported that the TSP was malfunctioning so I replaced it when I noticed that the wires were almost pulled out of it.
This didn't fix the problem.
- the computer now reports that the MAP sensor is faulty.
Any ideas here? I don't want to just keep replacing parts when they might be just fine.
thnx in advance.
Freshman User
Joined: Jan 2003
Posts: 35
Likes: 0
From: Victoria Canada
Stalling when cold
OK, thnx. I took the air control valve off, cleaned it, checked the sensor with a tester - all looks OK. Put it back on but there was no change - still have the problem.
According to the repair books specs, the sensor doesn't need to be replaced, since it is within the testing specs.
I'm going to take my EGR valve off and try cleaning it - I'll also try testing the MAP sensor.
According to the repair books specs, the sensor doesn't need to be replaced, since it is within the testing specs.
I'm going to take my EGR valve off and try cleaning it - I'll also try testing the MAP sensor.
Freshman User
Joined: Jan 2003
Posts: 37
Likes: 0
Stalling when cold
I had the same problem with a '92 302. I did the same things you did but also took off the throttle body and replaced the throttle position sensor. I also replaced the air intake motor and cleaned (thoroughly) the upper intake manifold. It worked like a charm! She purrs like a kitten and doesn't cut out.
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Freshman User
Joined: Jan 2003
Posts: 35
Likes: 0
From: Victoria Canada
Stalling when cold
Hey all. I replaced the MAP (manifold absolute pressure) sensor (the computer was complaining about it) but it now is worse! Not only is the computer indicating the problem without the engine running, but it also showing a MAP trouble code when running!
Is there more than one type of MAP sensor? The auto part place I got it from swears that there's only one type. My book however, says that there is a "frequency" type and a "voltage" type.
What gives? (anyone?)
thnx
Is there more than one type of MAP sensor? The auto part place I got it from swears that there's only one type. My book however, says that there is a "frequency" type and a "voltage" type.
What gives? (anyone?)
thnx
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Elder User
Joined: Oct 2002
Posts: 573
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From: Medina, Tn.
Stalling when cold
Have you reset your computer since these changes ? If not, disconnect the negative battery terminal for about 10 minutes. I also read somewhere here to also leave the passenger door open when doing this but with the battery disconnected, I see no reason for doing this.
New User
Joined: Jan 2003
Posts: 13
Likes: 0
From: USA
Stalling when cold
[updated:LAST EDITED ON 01-16-03 AT 05:46 PM (EST)]I have that same problem with the same engine...
mine the rpms kick up and down... then when it gets up to temp its all good except the throttle response... when your in (N) or (P) if you rev the engine how fast does it kick up?? mine is terribly slow... what causes that? Oh yeah, mine is a 88' red/tan eddie bauer
mine the rpms kick up and down... then when it gets up to temp its all good except the throttle response... when your in (N) or (P) if you rev the engine how fast does it kick up?? mine is terribly slow... what causes that? Oh yeah, mine is a 88' red/tan eddie bauer
Freshman User
Joined: Jan 2003
Posts: 35
Likes: 0
From: Victoria Canada
Stalling when cold
My throttle response is just great either cold or hot - just a little hesitation when cold, as I mentioned, I have to give it lots of gas to avoid stalling.
I have a feeling that it may be related to my EGR valve. I took a look at it and I can see it moving when I apply throttle, but it *may* be stuck slightly open when in an idle state due to carbon deposits and causing a false reading to the computer. I'm going to take it off and give it a good cleaning this weekend. I know the EVP sensor for the EGR is OK as it passes my multimeter tests.
Also, just for laughs - I noticed that my rad was leaking while I was bent over the engine ... doh!
Boy! Can you say "backyard mechanic"!
I have a feeling that it may be related to my EGR valve. I took a look at it and I can see it moving when I apply throttle, but it *may* be stuck slightly open when in an idle state due to carbon deposits and causing a false reading to the computer. I'm going to take it off and give it a good cleaning this weekend. I know the EVP sensor for the EGR is OK as it passes my multimeter tests.
Also, just for laughs - I noticed that my rad was leaking while I was bent over the engine ... doh!
Boy! Can you say "backyard mechanic"!
Junior User
Joined: Dec 2002
Posts: 51
Likes: 0
From: USA
Stalling when cold
The truck That I have now. Used to belong to my mother. I have been taking care of it over the years when I can. It used to act up alot and I would spray carb cleaner into the 2 holes for the air bypass valve and it would run a little better. I think she finally had the throttle postion senser replaced and a new EGR. I have had the truck for about 2 months now and the idle was surging and almost stalling. I replaced the air bypass valve and it runs like new again. Repacing parts can get expensive. I've also had the oil pan and valve covers gaskets done and had a radiator put in. the radiator was only 3 years old. not to mention a front bumper where she wacked a deer. I need to replace the front timing chain cover gasket, but that can wait till spring. I'ts too cold up here right now to work on it.
Senior User
Joined: Jan 2003
Posts: 229
Likes: 0
From: Covington USA
Stalling when cold
On my older 85 Bronco EFI 302 I had the same problems. I rebuilt injectors, cleaned intake, replace MAP. Nothing worked. What solved the problem for me was to replace both the EGR and the TPS and it ran fine. Now can someone solve the same problem for me on my 86 N/A 351???
Scott
1986 Bronco 5.8L 4x4
-also in the stables-
1985 F-250 S/C Diesel 4x4
1967 Bronco 289 4x4
Scott
1986 Bronco 5.8L 4x4
-also in the stables-
1985 F-250 S/C Diesel 4x4
1967 Bronco 289 4x4
Freshman User
Joined: Jan 2003
Posts: 35
Likes: 0
From: Victoria Canada
Stalling when cold
Well, I took the EGR off, cleaned it up with carb cleaner and a brush and put it back on and the problem was solved! Runs smooth as silk! I guess if it happens again, I'll just have to get a new EGR valve.
All in all, better than spending $thousands on a new truck.
thanks to all who responded!
All in all, better than spending $thousands on a new truck.
thanks to all who responded!
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